The &ldquo;reflect&rdquo; package is a useful library in the Go programming language that provides functions for working with reflection.&#xA;Hey! did you know that I wrote a completely Free Go programming language tutorial?, you can find it directly in the top menu bar or clicking this box. What is reflection in programming? Reflection is the ability of a program to inspect its own structure at runtime. This includes the ability to examine: types, values and metadata of objects in memory.

Go with Reflect: Boost Your Code's Flexibility

Almost all modern web applications perform some form of streaming, from video platforms to live streaming. In this post I explain how streaming works with HLS in such a simplified way that it will bring out your inner purist.&#xA;I leave you a minimal example of streaming in Go here in &#xA;&#xA;<a class="markdown-link" href="https://github.com/EduardoZepeda/go-hls-streaming-example" rel="noopener" target="_blank">my github repository</a>&#xA;, in case you want to see the code.&#xA;<h2 id="introduction-to-streaming">Introduction to streaming</h2>&#xA;Videos and audios contain a lot of encoded information, so their handling and downloading strongly impacts the bandwidth and usage of any server.&#xA;Streaming is a process that allows us to continuously send small amounts of information, in the case of audio or video, which can be stored or generated by a webcam or microphone in real time.&#xA;<h3 id="whats-wrong-with-the-http-protocol-for-playing-videos-and-audios">What&rsquo;s wrong with the HTTP protocol for playing videos and audios?</h3>&#xA;Normal users don&rsquo;t watch the complete audiovisual materials, yes, even you skip the paid advertising of your favorite influencers and sometimes you only watch 10 seconds of the video of some internet tutorials. If we were to use the HTTP protocol, the normal user would download a huge file, only to see a fraction of it. And he would have to wait for the download to complete before he could start playing it.&#xA;As you probably already know, sending the full video to all users would be pointless and consume huge amounts of bandwidth and I bet you don&rsquo;t want to make your cloud providers richer.&#xA;The solution? Streaming; an on-demand model, where each user receives only what they consume of the audio visual material, a little at a time, and if the user closes the video we do not send them the rest.&#xA;<h2 id="streaming-protocols">Streaming protocols</h2>&#xA;Before you start, you should know that there are quite a few streaming protocols, each with its own particularities that you can delve into on your own:&#xA;<ul>&#xA;<li>RTSP</li>&#xA;<li>RTP</li>&#xA;<li>RTCP</li>&#xA;<li>HLS</li>&#xA;<li>MPEG-DASH</li>&#xA;<li>HDS</li>&#xA;</ul>&#xA;I will explain HLS, why? Because HLS uses the HTTP protocol, so it does not require specialized servers, and it is compatible with any device that connects to the Internet. Finally, we add that lately it is a popular protocol for video streaming.&#xA;<h2 id="the-hls-protocol">The HLS protocol</h2>&#xA;The HLS protocol is a protocol based on HTTP, developed by Apple (yes, the same Apple), so any device that can connect to the Internet will be compatible with this protocol. HLS uses TCP underneath to send the information, avoiding the potential packet loss of its counterpart, UDP. And, as icing on the cake, HLS reacts to changes in internet speed and prioritizes the sending of lighter versions of our files (with lower quality, of course). The player in conjunction with the HLS library takes care of this automatically and you don&rsquo;t have to worry about the details.&#xA;<h2 id="preparation-of-the-files-for-hls-on-the-server">Preparation of the files for HLS on the server</h2>&#xA;Video transmission using HLS is carried out in several steps. First, the video is encoded and divided into segments of fixed duration. Then, these segments are uploaded to an HTTP server and provided to the user&rsquo;s media player via a playback index, a file with extension M3U8, which is a simple text file containing information about the available video segments. The segments can be uploaded to a CDN for higher performance, and some CDNs can even handle the entire process of encoding and segmenting your video.&#xA;To implement the protocol on the server side we need two steps:&#xA;<ul>&#xA;<li>Coding</li>&#xA;<li>Partitioning</li>&#xA;</ul>&#xA;<h3 id="coding">Coding</h3>&#xA;HLS requires our files to be in a specific encoding, so first we need to encode our media file to H.264 or H.265 (quite popular nowadays), so that any device can read them.&#xA;<div class="mermaid">flowchart LR&#xA; Video-->h.264&#xA; Video-->h.265&#xA;</div>&#xA; &#xA; &#xA; If your original file is not in that encoding, you can use tools like &#xA;&#xA;<a class="markdown-link" href="https://ffmpeg.org/" rel="noopener" target="_blank">ffmpeg</a>&#xA; to convert it.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-bash" data-lang="bash">ffmpeg -i &lt;input&gt; -vcodec libx264 -acodec aac &lt;output.mp4&gt;&#xA;</code></pre></div><h3 id="partitioning-and-creating-an-index-for-hls">Partitioning and creating an index for HLS</h3>&#xA;Then, the video or audio that we need to place in streaming is divided into several parts, generally with a few seconds of duration and, in order to know in which order each part goes, an index will also be created.&#xA;<div class="mermaid">flowchart LR&#xA; Video-->index.m3u8&#xA; Video-->index0.ts&#xA; Video-->index1.ts&#xA; Video-->index2.ts&#xA; Video-->indexn.ts&#xA;</div>&#xA; &#xA; &#xA; Partitioning for HLS can also be performed with ffmpeg.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-bash" data-lang="bash">ffmpeg -i &lt;tu-video&gt;.mp4 -profile:v baseline -level 3.0 -start_number 0 -hls_time 10 -hls_list_size 0 -f hls index.m3u8&#xA;</code></pre></div>The index that stores the order of each generated segment is a file with ending m3u8, whose content looks something like this:&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-bash" data-lang="bash">#EXTM3U&#xA;#EXT-X-VERSION:3&#xA;#EXT-X-TARGETDURATION:13&#xA;#EXT-X-MEDIA-SEQUENCE:0&#xA;#EXTINF:10.333333,&#xA;index0.ts&#xA;#EXTINF:9.750000,&#xA;index1.ts&#xA;#EXTINF:13.458333,&#xA;index2.ts&#xA;#EXTINF:9.083333,&#xA;index3.ts&#xA;#EXTINF:9.208333,&#xA;index4.ts&#xA;#EXTINF:8.333333,&#xA;# ... RESTO DE FRAGMENTOS ...&#xA;#EXTINF:2.416667,&#xA;index24.ts&#xA;#EXT-X-ENDLIST&#xA;</code></pre></div>Each segment of the video is numbered in ascending order, each with a ts extension so that you know where it belongs.&#xA;<h2 id="hls-at-the-customer">HLS at the customer</h2>&#xA;That was the hardest part, now we just need to pass the index to our client and the client device will do the following:&#xA;<ol>&#xA;<li>Download the index,</li>&#xA;<li>Read the table of contents</li>&#xA;<li>Obtain the segment you require for the video according to the table of contents.</li>&#xA;<li>Add it to the playback queue</li>&#xA;<li>Read the index again to get the next segment and repeat the process.</li>&#xA;</ol>&#xA;All of the above with Javascript, the HLS player library is already developed and takes care of all this automatically.&#xA;<div class="mermaid">sequenceDiagram&#xA; participant Client&#xA; participant Server&#xA; Client->>Server: GET index.m3u8&#xA; Server->>Client: index.m3u8&#xA; Client->>Server: GET index0.ts&#xA; Server->>Client: index0.ts&#xA; Client->>Server: GET index1.ts&#xA; Server->>Client: index1.ts&#xA;</div>&#xA; &#xA; &#xA; <h3 id="example-of-hls-at-the-client">Example of HLS at the client</h3>&#xA;Look at this super simple example:&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-html" data-lang="html">&lt;script src=&#34;https://cdn.jsdelivr.net/npm/hls.js@latest&#34;&gt;&lt;/script&gt;&#xA;&lt;!-- Cargamos la librería mediante un CDN o tu propio servidor --&gt;&#xA;&lt;video controls id=&#34;video&#34;&gt;&lt;/video&gt;&#xA;&lt;!-- Cargamos la etiqueta de video --&gt;&#xA;</code></pre></div>And now we proceed to load the index, or in another way, the file&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-javascript" data-lang="javascript">var video = document.getElementById(&#39;video&#39;);&#xA; if(Hls.isSupported()) {&#xA; // Si soporta HlS &#xA; var hls = new Hls();&#xA; hls.loadSource(&#39;http://tuservidor.com/ruta/index.m3u8&#39;);&#xA; // carga el índice&#xA; hls.attachMedia(video);&#xA; //Una vez cargado el índice reproduce el video&#xA; hls.on(Hls.Events.MANIFEST_PARSED,function() {&#xA; video.play();&#xA; });&#xA; } else if (video.canPlayType(&#39;application/vnd.apple.mpegurl&#39;)) {&#xA; video.src = &#39;http://tuservidor.com/ruta/stream&#39;;&#xA; video.addEventListener(&#39;loadedmetadata&#39;,function() {&#xA; video.play();&#xA; });&#xA; }&#xA;</code></pre></div>If you were to examine the browser you would see that the video is loaded bit by bit, and as it is needed, the browser requests the next video segment and automatically adds it to the playback.&#xA;<a href="https://coffeebytes.dev/en/stream-your-videos-and-audios-a-simple-introduction-to-streaming-with-hls-for-your-applications/images/hls.jpg" aria-label="Download HLS index and video snippets in browser">&#xA;&#xA;<figure>&#xA; <img class="md-image" width="1000" height="535" loading="lazy" src="https://coffeebytes.dev/en/stream-your-videos-and-audios-a-simple-introduction-to-streaming-with-hls-for-your-applications/images/hls.jpg" alt="Download HLS index and video snippets in browser"/>&#xA; <figcaption>Download HLS index and video snippets in browser</figcaption>&#xA;</figure>&#xA;&#xA;</a>&#xA;<h2 id="preprocessing-of-videos-for-hls-on-the-server">Preprocessing of videos for HLS on the server</h2>&#xA;If you will be in charge of processing the videos yourself, you may want to implement a service that will take care of encoding the videos to h.264 or h.265 and then split them into segments. After that you may want to link them to a notification system that lets your application know that the video processing is finished and can be played.&#xA;You may also want to have variants of the video with different quality, to be used in case of a slower connection on the client.&#xA;Of course, all of the above already depends on your architectural needs.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-bash" data-lang="bash">#EXTM3U&#xA;#EXT-X-VERSION:6&#xA;#EXT-X-STREAM-INF:BANDWIDTH=1210000,RESOLUTION=480x360,CODECS=&#34;avc1.640015,mp4a.40.2&#34;&#xA;index-360p.m3u8&#xA;&#xA;#EXT-X-STREAM-INF:BANDWIDTH=2283600,RESOLUTION=640x480,CODECS=&#34;avc1.64001e,mp4a.40.2&#34;&#xA;index-480p.m3u8&#xA;&#xA;#EXT-X-STREAM-INF:BANDWIDTH=3933600,RESOLUTION=1280x720,CODECS=&#34;avc1.64001f,mp4a.40.2&#34;&#xA;index-720p.m3u8&#xA;</code></pre></div>With this you have the minimum to create a basic example and go from there on your own.&#xA;

Almost all modern web applications perform some form of streaming, from video platforms to live streaming. In this post I explain how streaming works with HLS in such a simplified way that it will bring out your inner purist.&#xA;I leave you a minimal example of streaming in Go here in my github repository , in case you want to see the code.&#xA;Introduction to streaming Videos and audios contain a lot of encoded information, so their handling and downloading strongly impacts the bandwidth and usage of any server.

Stream your videos and audios: HLS for your applications

In my post about &#xA;&#xA;<a class="markdown-link" href="https://coffeebytes.dev/en/basic-characteristics-of-an-api-rest-api/">the basic features about a REST API</a>&#xA; I mentioned to you that, besides REST, there were other types of APIS, one of them is gRPC, which is derived from RPC, so let&rsquo;s start the post talking about the latter.&#xA;<h2 id="what-is-rpc">What is RPC?</h2>&#xA;RPC stands for Remote Procedure Call, which, in simple words, refers to invoking code execution on one machine from another machine, usually a server, in such a way that, to the programmer, it appears that the execution was performed locally.&#xA;<h3 id="how-does-rpc-work">How does RPC work?</h3>&#xA;The more detailed process is as follows:&#xA;<ol>&#xA;<li>The client makes the call by sending a message to the network.</li>&#xA;<li>The call includes a procedure to encode the methods, request types, and response type in the appropriate format.&#xA;request and response type in the appropriate format.&#xA;(&#xA;&#xA;<a class="markdown-link" href="https://es.wikipedia.org/wiki/Marshalling" rel="noopener" target="_blank">marshalling</a>&#xA;). This procedure is called the stub.</li>&#xA;<li>The server receives the request and uses the stub to decode the data into the appropriate format of the RPC environment and to know what to execute and with what information.</li>&#xA;<li>The task is executed on the server and a response is generated as a result.</li>&#xA;<li>The response from the server is encoded using the stub and sent to the client.</li>&#xA;<li>The client receives the response and decodes it in the appropriate format.</li>&#xA;</ol>&#xA;<a href="https://coffeebytes.dev/en/unleash-your-apis-potential-with-grpc-and-protobuffers/images/rpc-esquema.jpg" aria-label="Schematic diagram of gRPC operation">&#xA;&#xA;<figure>&#xA; <img class="md-image" width="1080" height="669" loading="lazy" src="https://coffeebytes.dev/en/unleash-your-apis-potential-with-grpc-and-protobuffers/images/rpc-esquema.jpg" alt="Schematic diagram of gRPC operation"/>&#xA; <figcaption>Schematic diagram of gRPC operation</figcaption>&#xA;</figure>&#xA;&#xA;</a>&#xA;Did you notice I mentioned data encryption? Well, one aspect of RPC to note is that it requires both client and server to use the same programming language, which makes it a disadvantage in environments where multiple programming languages can be mixed.&#xA;Now, let&rsquo;s go to gRPC.&#xA;<h2 id="what-is-grpc">What is gRPC?</h2>&#xA;Google took into account the shortcomings of RPC and decided to improve it by creating gRPC.&#xA;gRPC emulates RPC with the advantage that it does not need to use the same programming language to perform machine-to-machine communication.&#xA;And what happened to data encryption? Well, Google developed Protocol Buffers (or protobuffers) to use them as the default format for gRPC in the exchange of information between machines and achieve better performance than other formats such as JSON or XML.&#xA;<h2 id="what-are-protobuffers">What are protobuffers?</h2>&#xA;You have probably worked with APIs and have noticed that, when communicating with an API, there is an exchange of information; you send information to the API and it returns a response. This exchange of information can take place in different formats, plain text, XML (if you are old school) or JSON (the most popular today).&#xA;For this exchange to occur, the information must be serialized when it is sent and then deserialized.&#xA;<div class="mermaid">graph TD;&#xA; JSON-- serialización -->data;&#xA; data-- deserialización -->JSON;&#xA;</div>&#xA; &#xA; &#xA; Protocol Buffers (protobuffers from now on) are a completely language and platform agnostic format, which gRPC uses to serialize and deserialize structured data only that, instead of using JSON, XML or another format, it is done directly in binary. This, as you know, makes it much more efficient than using a more human-friendly format like JSON.&#xA;<a href="https://coffeebytes.dev/en/unleash-your-apis-potential-with-grpc-and-protobuffers/images/protobuffers-grpc.jpg" aria-label="The compilation of the .proto file is unidirectional, while the serialization deserialization is bidirectional.">&#xA;&#xA;<figure>&#xA; <img class="md-image" width="1400" height="800" loading="lazy" src="https://coffeebytes.dev/en/unleash-your-apis-potential-with-grpc-and-protobuffers/images/protobuffers-grpc.jpg" alt="The compilation of the .proto file is unidirectional, while the serialization deserialization is bidirectional."/>&#xA; <figcaption>The compilation of the .proto file is unidirectional, while the serialization deserialization is bidirectional.</figcaption>&#xA;</figure>&#xA;&#xA;</a>&#xA;<h3 id="how-to-convert-information-with-protobuffers">How to convert information with protobuffers?</h3>&#xA;Simplifying, to create the necessary code to serialize and deserialize in the protobuffers format we start from a file with extension .proto, this will be in charge of modeling the information that we will use to communicate, as well as the services that will be available for our API. Basically it is to tell you how our information is structured and what changes we are going to make on this information along with what they will receive as input and return as response.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-go" data-lang="go">message DataResponse {&#xA; int32 id = 1;&#xA; string info = 2;&#xA; string result = 3;&#xA;}&#xA;&#xA;message DataRequest {&#xA; int32 id = 1;&#xA; string info = 2;&#xA;}&#xA;&#xA;service Publisher {&#xA; rpc ProcessData (DataRequest) returns (DataResponse) {}&#xA;}&#xA;</code></pre></div>After defining our models and services, these files are compiled, and will generate the necessary code to serialize and deserialize the information in the language we want, both on the client and server side. We do not have to worry about the details in this regard.&#xA;Currently the &#xA;&#xA;<a class="markdown-link" href="https://developers.google.com/protocol-buffers" rel="noopener" target="_blank">protobuffers format is available for C#, C++, Go, Objective-C, Java, Python and Ruby.</a>&#xA; Check the documentation for your particular language.&#xA;<h2 id="rest-vs-grpc">REST vs gRPC</h2>&#xA;But how efficient is gRPC compared to REST? Check out this comparison by &#xA;&#xA;<a class="markdown-link" href="https://laptrinhx.com/grpc-vs-rest-performance-comparison-2418648833/" rel="noopener" target="_blank">Matthew Leung</a>&#xA;.&#xA;<table>&#xA;<thead>&#xA;<tr>&#xA;<th></th>&#xA;<th>gRPC</th>&#xA;<th>REST</th>&#xA;</tr>&#xA;</thead>&#xA;<tbody>&#xA;<tr>&#xA;<td>Peticiones/Segundo</td>&#xA;<td>48.00</td>&#xA;<td>4.00</td>&#xA;</tr>&#xA;<tr>&#xA;<td>Latencia de la petición</td>&#xA;<td>6.15</td>&#xA;<td>8.00</td>&#xA;</tr>&#xA;<tr>&#xA;<td>CPU ms/s</td>&#xA;<td>832.00</td>&#xA;<td>404.00</td>&#xA;</tr>&#xA;<tr>&#xA;<td>CPU/petición</td>&#xA;<td>17.33</td>&#xA;<td>101.11</td>&#xA;</tr>&#xA;</tbody>&#xA;</table>&#xA;As you can see gRPC is much faster than REST plus JSON when processing requests, performance tests vary from 5 to 10 times.&#xA;<h3 id="why-is-grpc-so-efficient">Why is gRPC so efficient?</h3>&#xA;There are several factors that make gRPCs extremely efficient for exchanging information:&#xA;<ul>&#xA;<li>Uses protobuffers as a structure for data exchange.</li>&#xA;<li>The use of HTTP2 and multiplexing.</li>&#xA;<li>Compression of headers.</li>&#xA;</ul>&#xA;The binary format of the protobuffers translates into a smaller amount of information to be transported and easier and more efficient handling by computers.&#xA;On the other hand, the use of HTTP/2 allows gRPC to send multiple streams of information over a single TCP connection (multiplexing) in a bidirectional and asynchronous manner.&#xA;<h2 id="types-of-grpc-and-streaming">Types of gRPC and streaming</h2>&#xA;The HTTP/2 protocol is versatile and allows gRPC to support four types of client-server communications:&#xA;<ul>&#xA;<li>Unary. The client and server communicate using a simple request and response, as in REST.&#xA;response, as in REST.</li>&#xA;</ul>&#xA;<div class="mermaid">graph TD;&#xA; Client-->Server;&#xA; Server-->Client;&#xA;</div>&#xA; &#xA; &#xA; Server-side streaming. The server sends multiple responses to&#xA;a request from the client.&#xA;<div class="mermaid">graph TD;&#xA; Client-->Server;&#xA; Server-->Client;&#xA; Server-->Client;&#xA; Server-->Client;&#xA;</div>&#xA; &#xA; &#xA; <ul>&#xA;<li>Client-side streaming. The client sends multiple requests to the server&#xA;The client sends multiple requests to the server and the server responds with a single response.</li>&#xA;</ul>&#xA;<div class="mermaid">graph TD;&#xA; Client-->Server;&#xA; Client-->Server;&#xA; Client-->Server;&#xA; Server-->Client;&#xA;</div>&#xA; &#xA; &#xA; <ul>&#xA;<li>Two-way streaming**. Both the client and the server send multiple requests and&#xA;multiple requests and responses, respectively.</li>&#xA;</ul>&#xA;<div class="mermaid">graph TD;&#xA; Server-->Client;&#xA; Server-->Client;&#xA; Server-->Client;&#xA; Client-->Server;&#xA; Client-->Server;&#xA; Client-->Server;&#xA;</div>&#xA; &#xA; &#xA; As you can see this is super useful for services that require constant exchanges of large amounts of information, such as microservices.&#xA;<h2 id="other-grpc-capabilities">Other gRPC capabilities</h2>&#xA;<h3 id="interceptors">Interceptors</h3>&#xA;gRPC has a mechanism to intercept messages and modify them to your liking, you can think of it as a kind of middleware.&#xA;<h3 id="load-balancing">Load balancing</h3>&#xA;gRPC provides load balancing capabilities natively.&#xA;<h2 id="reference-resources">Reference resources</h2>&#xA;<ul>&#xA;<li>&#xA;&#xA;<a class="markdown-link" href="https://learn.microsoft.com/en-us/windows/win32/rpc/how-rpc-works" rel="noopener" target="_blank">How RPC works?</a>&#xA;</li>&#xA;<li>&#xA;&#xA;<a class="markdown-link" href="https://www.youtube.com/watch?v=gnchfOojMk4" rel="noopener" target="_blank">What&rsquo;s RPC an introduction guide</a>&#xA;</li>&#xA;<li>&#xA;&#xA;<a class="markdown-link" href="https://itnext.io/a-minimalist-guide-to-grpc-e4d556293422" rel="noopener" target="_blank">RPC minimalist guide</a>&#xA;</li>&#xA;<li>&#xA;&#xA;<a class="markdown-link" href="https://devopedia.org/grpc" rel="noopener" target="_blank">Devopedia</a>&#xA;</li>&#xA;</ul>&#xA;

In my post about the basic features about a REST API I mentioned to you that, besides REST, there were other types of APIS, one of them is gRPC, which is derived from RPC, so let&rsquo;s start the post talking about the latter.&#xA;What is RPC? RPC stands for Remote Procedure Call, which, in simple words, refers to invoking code execution on one machine from another machine, usually a server, in such a way that, to the programmer, it appears that the execution was performed locally.

Unleash Your API's Potential With gRPC and Protobuffers

ChatGPT is breaking with everything previously known in artificial intelligence, some developers are worried that it may replace them in their jobs, just as Github Copilot threatened at the time. In this post I test ChatGPT&rsquo;s supposed intelligence against three codewars challenges.&#xA;How does Codewars work? Before we start you need to understand that Codewars is a social network for programmers where code challenges written by the same users are shared.

I Test ChatGPT With Codewars Coding Challenges

In frameworks like &#xA;&#xA;<a class="markdown-link" href="https://coffeebytes.dev/en/why-should-you-use-django-framework/">Django, migrations are created automatically</a>&#xA;, from the models. However, in languages like go, as long as we are not using an ORM, migrations will be done manually.&#xA;&#xA;&#xA;&#xA; <img width="60" height="60" src="https://res.cloudinary.com/dwrscezd2/image/upload/v1717959563/Go_gopher_favicon_uzxa20.svg" alt="">&#xA; <a target="_blank" rel=”nofollow” href="https://coffeebytes.dev/en/pages/go-programming-language-tutorial/">&#xA; Hey! did you know that I wrote a completely Free Go programming language tutorial?, you can find it directly in the top menu bar or clicking this box.</a>&#xA;&#xA;&#xA;<h2 id="what-is-a-database-migration">What is a database migration?</h2>&#xA;A migration is an abstraction to manage the state and changes that occur in a database. Instead of executing SQL statements one by one manually, we automate the process by writing all the necessary SQL and running it automatically.&#xA;A migration consists of two files with SQL statements:&#xA;<ul>&#xA;<li>file up: To make changes in the database.</li>&#xA;<li>down file: To revert changes in the database.</li>&#xA;</ul>&#xA;For this case they are called up and down, but you could give them any other names; such as forward and backward, or next and previous.&#xA;For example:&#xA;<a href="https://coffeebytes.dev/en/go-migration-tutorial-with-migrate/images/migrations-in-go.jpg" aria-label="Manually generated migration files">&#xA;&#xA;<figure>&#xA; <img class="md-image" width="1200" height="700" loading="lazy" src="https://coffeebytes.dev/en/go-migration-tutorial-with-migrate/images/migrations-in-go.jpg" alt="Manually generated migration files"/>&#xA; <figcaption>Manually generated migration files</figcaption>&#xA;</figure>&#xA;&#xA;</a>&#xA;<h3 id="migrations-are-complementary">Migrations are complementary</h3>&#xA;Notice how the migrations are reversible and complementary; one performs an action and the other reverts it.&#xA;Following this logic we can make changes to the database and then revert them.&#xA;These two files can be generated automatically (as in the case of Django, from the models) or we can write them directly in SQL, as in the case of go.&#xA;<h2 id="migrate-installation">Migrate installation</h2>&#xA;To handle migrations we are going to use a tool called migrate, written in go.&#xA;Migrate can be downloaded directly from their &#xA;&#xA;<a class="markdown-link" href="https://github.com/golang-migrate/migrate/releases" rel="noopener" target="_blank">github releases section</a>&#xA;.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-bash" data-lang="bash">curl -L https://github.com/golang-migrate/migrate/releases/download/v4.15.2/migrate.linux-amd64.tar.gz | tar xvz&#xA;mv migrate.linux-amd64 $GOPATH/bin/migrate&#xA;</code></pre></div>You should then be able to see which version you have installed.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-bash" data-lang="bash">migrate -version&#xA;4.15.2&#xA;</code></pre></div><h2 id="migration-files-creation-with-migrate-in-go">Migration files creation with migrate in Go</h2>&#xA;To create the pair of migration files, which I told you about earlier, we run the following command:&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-bash" data-lang="bash">migrate create -seq -ext=.sql -dir=./migrations &lt;nombre_de_la_migración&gt;&#xA;</code></pre></div>I explain what each flag does:&#xA;<ul>&#xA;<li>seq: indicates that it will be sequential, so that it begins with 000001 and continues until 00000n; the total of migrations that we have.</li>&#xA;<li>dir: will indicate the directory</li>&#xA;<li>ext: the extension of the file, in this case sql.</li>&#xA;<li>At the end the name we want the migration to have. I will use create_first_table for this example.</li>&#xA;</ul>&#xA;After executing the command, you will have two migration files, one with extension .up.sql and the other with extension .down.sql inside the migrations folder.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-bash" data-lang="bash">ls&#xA;000001_create_first_table.up.sql 000001_create_first_table.down.sql&#xA;</code></pre></div>These files must be edited manually and the SQL statements must be placed inside them.&#xA;<h3 id="example-of-migrations-in-go-with-postgres">Example of migrations in go with postgres</h3>&#xA;For example, to create a hypothetical table users in a postgres database:&#xA;For the up:&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-sql" data-lang="sql">CREATE TABLE &#34;users&#34; (&#34;id&#34; serial NOT NULL PRIMARY KEY, &#34;name&#34; varchar(50) NOT NULL);&#xA;</code></pre></div>And, to reverse the above, there is the down file:&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-sql" data-lang="sql">DROP TABLE &#34;users&#34;;&#xA;</code></pre></div>Again, notice how both SQL statements are complementary; one creates a table and the other deletes it. But you can put more than one statement and they can be anything you want, an index, a constraint, a routine, etc.&#xA;<h2 id="execute-migrations-with-migrate-in-go">Execute migrations with migrate in Go</h2>&#xA;So far we have only created the migration files, but we have not let the program know where the database is.&#xA;Before making any changes to the database, we will need to indicate the access address to the database in the following format [engine]://[user]:[password]@[domain]/[database].&#xA;And, obviously, the most convenient and safest thing to do is to save this address in &#xA;&#xA;<a class="markdown-link" href="https://coffeebytes.dev/en/linux-basic-commands-passwd-du-useradd-usermod-fdisk-lscpu-apt-which/">an environment variable</a>&#xA;.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-bash" data-lang="bash">DATABASE=[engine]://[user]:[password]@[domain]/[database]&#xA;</code></pre></div>Now we have a database to connect to.&#xA;<h3 id="apply-migrations">Apply migrations</h3>&#xA;To apply all migrations we will use the up command. Migrate will automatically detect the numbering and run all migrations up in ascending order.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-bash" data-lang="bash">migrate -path=./migrations -database=$DATABASE up&#xA;</code></pre></div><h3 id="remove-migrations">Remove migrations</h3>&#xA;On the other hand, to revert all migrations we will use the down command. Migrate will automatically detect the numbering and run all migrations down in descending order.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-bash" data-lang="bash">migrate -path=./migrations -database=$DATABASE down&#xA;</code></pre></div><h3 id="go-to-a-specific-migration">Go to a specific migration</h3>&#xA;Whereas, if we want to go to a specific migration, we will use the goto command followed by the migration number to which we want to take the database.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-bash" data-lang="bash">migrate -path=./migrations -database=$DATABASE goto &lt;migration number&gt;&#xA;</code></pre></div>Migrate will detect the active migration and run the corresponding up or down migrations to bring the database to that state.&#xA;<h2 id="the-migration-table">The migration table</h2>&#xA;And how does the tool know which migration it is in? After each change we make to the database, the migrate tool will store the state of our database in a table called schema_migrations that looks like this:&#xA;<a href="https://coffeebytes.dev/en/go-migration-tutorial-with-migrate/images/schema_migrations.png" aria-label="schema_migrations table in postgres&amp;quot;">&#xA;&#xA;<figure>&#xA; <img class="md-image" width="219" height="71" loading="lazy" src="https://coffeebytes.dev/en/go-migration-tutorial-with-migrate/images/schema_migrations.png" alt="schema_migrations table in postgres&amp;quot;"/>&#xA; <figcaption>Migrations table where the current state is 1, selected in blue</figcaption>&#xA;</figure>&#xA;&#xA;</a>&#xA;<h3 id="column-version">Column version</h3>&#xA;Notice how the version column stores the status of the current migration. This way migrate records which version of the migrations it is in.&#xA;<h3 id="dirty-column">Dirty column</h3>&#xA;In addition, this table also contains a column called dirty that indicates if there was any conflict in the migration. In the latter case it will be necessary to repair it manually and force a new state in the table.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-bash" data-lang="bash">migrate -path=./migrations -database=$DATABASE force 1&#xA;</code></pre></div><h2 id="migrations-to-remote-databases">Migrations to remote databases</h2>&#xA;The Migrate tool also supports remote migrations such as:&#xA;<ul>&#xA;<li>Filesystem</li>&#xA;<li>io/fs</li>&#xA;<li>Go-Bindata</li>&#xA;<li>pkger</li>&#xA;<li>GitHub</li>&#xA;<li>GitHub Enterprise</li>&#xA;<li>Bitbucket</li>&#xA;<li>Gitlab</li>&#xA;<li>AWS S3</li>&#xA;<li>Google Cloud Storage</li>&#xA;</ul>&#xA;Each of these endpoints requires a specific syntax. For example, the Amazon S3 endpoint looks like this:&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-bash" data-lang="bash">migrate -source=&#34;s3://&lt;bucket&gt;/&lt;path&gt;&#34; -database=$DATABASE up&#xA;</code></pre></div>With this you already know the basics about migrations and you probably also value a lot more tools and &#xA;&#xA;<a class="markdown-link" href="https://coffeebytes.dev/en/why-should-you-use-django-framework/">ORMs that take care of this automatically, such as Django</a>&#xA;, Ruby on Rails, South, etc.&#xA;

In frameworks like Django, migrations are created automatically , from the models. However, in languages like go, as long as we are not using an ORM, migrations will be done manually.&#xA;Hey! did you know that I wrote a completely Free Go programming language tutorial?, you can find it directly in the top menu bar or clicking this box. What is a database migration? A migration is an abstraction to manage the state and changes that occur in a database.

Go Migration Tutorial with migrate

Today I&rsquo;m going to talk about a topic that is often overlooked in most tutorials: handling application closing. What do I mean? To those times when you have to close an application, but there may be pending tasks running, open connections or you simply want to leave a record, in the form of a log, that the application was closed.&#xA;&#xA;&#xA;&#xA; <img width="60" height="60" src="https://res.cloudinary.com/dwrscezd2/image/upload/v1717959563/Go_gopher_favicon_uzxa20.svg" alt="">&#xA; <a target="_blank" rel=”nofollow” href="https://coffeebytes.dev/en/pages/go-programming-language-tutorial/">&#xA; Hey! did you know that I wrote a completely Free Go programming language tutorial?, you can find it directly in the top menu bar or clicking this box.</a>&#xA;&#xA;&#xA;<h2 id="signals-in-linux">Signals in Linux</h2>&#xA;As you probably already know, the Linux kernel is in charge of &ldquo;lending&rdquo; resources to go applications (or any other application) to run.&#xA;Because linux is the kernel of the system, it is able to call back those resources at any time and close the application.&#xA;Linux can &ldquo;nicely&rdquo; ask applications for the resources it lent them or &ldquo;take them away&rdquo; by force. To do this, Linux sends a series of signals to the application, some of which can be captured and handled by the application itself, with code in Go.&#xA;<h3 id="main-linux-signals">Main Linux signals</h3>&#xA;There are quite a few Linux signals, but here are the most important ones for this example:&#xA;<table>&#xA;<thead>&#xA;<tr>&#xA;<th>Signal</th>&#xA;<th>Value</th>&#xA;<th>Action</th>&#xA;<th>Comment</th>&#xA;<th>Command</th>&#xA;<th>Keyboard Shortcut</th>&#xA;</tr>&#xA;</thead>&#xA;<tbody>&#xA;<tr>&#xA;<td>SIGINT</td>&#xA;<td>2</td>&#xA;<td>Term</td>&#xA;<td>Interrupt from keyboard</td>&#xA;<td>kill -2 pid</td>&#xA;<td>CTRL+C</td>&#xA;</tr>&#xA;<tr>&#xA;<td>SIGTERM</td>&#xA;<td>15</td>&#xA;<td>Term</td>&#xA;<td>Terminate a process in a controlled manner</td>&#xA;<td>kill -15 pid</td>&#xA;<td>CTRL+C</td>&#xA;</tr>&#xA;<tr>&#xA;<td>SIGKILL</td>&#xA;<td>9</td>&#xA;<td>Term</td>&#xA;<td>Terminate a process in a forced manner, cannot be handled by</td>&#xA;<td>kill -9 pid</td>&#xA;<td></td>&#xA;</tr>&#xA;</tbody>&#xA;</table>&#xA;In Linux, these signals can be sent to an application via the &#xA;&#xA;<a class="markdown-link" href="https://coffeebytes.dev/en/linux-basic-commands-passwd-du-useradd-usermod-fdisk-lscpu-apt-which/">kill command</a>&#xA;, specifying the value of the signal and the pid of the application.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-go" data-lang="go">kill -&lt;valor&gt; &lt;pid&gt;&#xA;// kill -2 1234&#xA;</code></pre></div><h2 id="signal-handling-in-go">Signal handling in Go</h2>&#xA;In go, when we want to listen to the signals sent by the Linux kernel, we use the Notify method of the signal package. The Notify method will send our signal on a channel, which it will receive as the first argument. The second and third arguments are the signals that our method will listen for.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-go" data-lang="go">func gracefulShutdown() {&#xA; quit := make(chan os.Signal, 1)&#xA; signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)&#xA; // ...&#xA;}&#xA;</code></pre></div><h3 id="managing-signals-with-channels">Managing signals with channels</h3>&#xA;Now we have a channel that receives our signal, but&hellip; what do we do with it?&#xA;Remember that, in go, &#xA;&#xA;<a class="markdown-link" href="https://coffeebytes.dev/en/go-channels-understanding-the-goroutines-deadlocks/">operations that send or receive channel values are blocking inside their own goroutine</a>&#xA;, i.e., they keep code execution on hold?&#xA;In this case we are going to leave a variable expected by the value of the channel that we have just created, blocking the code at that point.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-go" data-lang="go">func gracefulShutdown() {&#xA; quit := make(chan os.Signal, 1)&#xA; signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)&#xA; s := &lt;-quit&#xA; fmt.Println(&#34;Cerrando aplicación&#34;, s)&#xA; // ...&#xA;}&#xA;</code></pre></div>This way the application will wait until it receives any signal (SIGINT or SIGTERM) from Linux and, once it receives it, it will execute the rest of the function code.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-go" data-lang="go">func gracefulShutdown() {&#xA; quit := make(chan os.Signal, 1)&#xA; signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)&#xA; s := &lt;-quit&#xA; fmt.Println(&#34;Cerrando aplicación&#34;, s)&#xA; // ... resto del código&#xA;}&#xA;</code></pre></div>Finally, for this function to run correctly, we need it to run inside its &#xA;&#xA;<a class="markdown-link" href="https://coffeebytes.dev/en/go-introduction-to-goroutines-and-concurrency/">own goroutine</a>&#xA;. To do this, simply prefix the function call with the keyword go.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-go" data-lang="go">func main() {&#xA; // ...&#xA; go gracefulShutdown()&#xA; // ...&#xA;}&#xA;</code></pre></div><h3 id="capturing-a-signit-signal">Capturing a SIGNIT signal</h3>&#xA;If we run a web server or any other permanent process and then issue a SIGNIT signal by pressing CTRL + C in the terminal or with the kill command, linux will receive the signal and notify our application to shut down.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-bash" data-lang="bash">go run main.go&#xA;Empezando el servidor. Pid: 8830&#xA;&#xA;kill -2 8830&#xA;Cerrando el servidor: interrupt&#xA;</code></pre></div>Consider that the Pid may be different for you.&#xA;<h3 id="capturing-a-sigterm-signal">Capturing a SIGTERM signal</h3>&#xA;To emit a SIGTERM signal, we execute the GNU/Linux kill command, which will terminate the application. Our application will receive the signal through the channel and execute the rest of the code.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-bash" data-lang="bash">go run main.go&#xA;Empezando el servidor. Pid: 9619&#xA;&#xA;kill -15 9616&#xA;Cerrando el servidor: terminated&#xA;</code></pre></div>Of course, ideally, you should go beyond printing a message and take care of all those tasks you want that require a more orderly completion process.&#xA;<h2 id="example-of-graceful-shutdown-with-a-web-server">Example of graceful shutdown with a web server</h2>&#xA;I leave you the complete example with a web server written entirely in go.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-go" data-lang="go">package main&#xA;&#xA;import (&#xA; &#34;fmt&#34;&#xA; &#34;log&#34;&#xA; &#34;net/http&#34;&#xA; &#34;os&#34;&#xA; &#34;os/signal&#34;&#xA; &#34;syscall&#34;&#xA;)&#xA;&#xA;func getRoot(w http.ResponseWriter, r *http.Request) {&#xA; //io.WriteString(w, &#34;This is my website!\n&#34;)&#xA; w.Write([]byte(&#34;Este es mi sitio web!\n&#34;))&#xA;}&#xA;&#xA;func gracefulShutdown() {&#xA; quit := make(chan os.Signal, 1)&#xA; signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)&#xA; s := &lt;-quit&#xA; fmt.Println(&#34;Cerrando el servidor:&#34;, s)&#xA; os.Exit(0)&#xA;}&#xA;&#xA;func main() {&#xA; pid := os.Getpid() &#xA; fmt.Println(&#34;Empezando el servidor. Pid:&#34;, pid)&#xA; go gracefulShutdown()&#xA; http.HandleFunc(&#34;/&#34;, getRoot)&#xA; if err := http.ListenAndServe(&#34;:8000&#34;, nil); err != nil {&#xA; &#x9;log.Fatalf(&#34;El servidor fallo al iniciar. Error: %v&#34;, err.Error())&#xA; }&#xA;}&#xA;</code></pre></div>After running it, try to cancel the application with CTRL + C or with the terminal with the kill command, and see how the message is printed and the application is terminated in a more orderly and controlled manner.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-bash" data-lang="bash">go run main.go&#xA;&#xA;CTRL + C&#xA;Empezando el servidor. Pid: 8830&#xA;Cerrando el servidor: interrupt&#xA;</code></pre></div>

Today I&rsquo;m going to talk about a topic that is often overlooked in most tutorials: handling application closing. What do I mean? To those times when you have to close an application, but there may be pending tasks running, open connections or you simply want to leave a record, in the form of a log, that the application was closed.&#xA;Hey! did you know that I wrote a completely Free Go programming language tutorial?

Go: Handling Signals for Closing Applications

With django and reportlab we can generate PDFs dynamically, using information from our database, user input or any other business logic we want.&#xA;Installation of reportlab The first thing will be to install reportlab, we can use pip, pipenv or any other package manager you want.&#xA;pip install reportlab # pip install reportlab Define PDF response type in Django Once installed, the first lines we will write will be to make sure that the browser knows that we will return a pdf, we will do it through an HTTP header, the Content-Type header, through the content_type variable.

Generating PDFs with Django and Reportlab

On Saturday, August 6, 2022 I sat for and approved my Microsoft Azure AZ-900 certification exam.&#xA;<h2 id="what-does-az-900-certification-consist-of">What does AZ-900 certification consist of?</h2>&#xA;The AZ-900 Fundamentals certification ensures that a person knows all the basic services that Microsoft&rsquo;s cloud, Azure, and its enterprise applications have.&#xA;For practical purposes, it prepares you to serve as an intermediary who recommends Microsoft Azure services to a company or third party, according to their needs. Or, as a software professional, you can take advantage of all the services that Azure has to offer. It often reads like a no-brainer, but Azure has a wealth of services.&#xA;To achieve the above you need to know the basic architecture of Azure, its different services: compute, storage, artificial intelligence, etc., their special features, differences, and their respective use cases.&#xA;<h2 id="my-examination-process">My examination process</h2>&#xA;The exam was conducted through the &#xA;&#xA;<a class="markdown-link" href="https://www.evaluaasi.com/" rel="noopener" target="_blank">Evaluaasi platform</a>&#xA;, through which you download a program that connects to a remote desktop to take the exam. This program will monitor your computer and connected devices, probably to prevent a user from cheating in some way; I have heard that some evaluation processes are so strict that they ask to see the room in which you will take the exam before starting. That wasn&rsquo;t my case though.&#xA;<a href="https://coffeebytes.dev/en/azure-az-900-certification-exam-my-experience/images/evaluaasi-plataforma.jpg" aria-label="Evaluaasi platform">&#xA;&#xA;<figure>&#xA; <img class="md-image" width="1672" height="576" loading="lazy" src="https://coffeebytes.dev/en/azure-az-900-certification-exam-my-experience/images/evaluaasi-plataforma.jpg" alt="Evaluaasi platform"/>&#xA; <figcaption>Evaluaasi platform home screen</figcaption>&#xA;</figure>&#xA;&#xA;</a>&#xA;When it is time for the exam, and once connected to the remote desktop, an evaluator will enter his or her username and password to give you access to the exam.&#xA;According to what I was told in one of their emails, the application of the exam can be postponed and they are quite flexible.&#xA;<h2 id="az-900-examination-format">AZ-900 Examination format</h2>&#xA;The duration of the exam is approximately 60 minutes and has 45 questions, there are multiple choice questions, true or false, matching columns and even some where you have to choose an option from the Microsoft marketplace directly, just as if you were in the browser.&#xA;<a href="https://coffeebytes.dev/en/azure-az-900-certification-exam-my-experience/images/portal-azure.png" aria-label="Azure Portal screenshot">&#xA;&#xA;<figure>&#xA; <img class="md-image" width="1051" height="209" loading="lazy" src="https://coffeebytes.dev/en/azure-az-900-certification-exam-my-experience/images/portal-azure.png" alt="Azure Portal screenshot"/>&#xA; <figcaption>Azure Portal</figcaption>&#xA;</figure>&#xA;&#xA;</a>&#xA;You can skip questions and mark them to come back to them later, which I highly recommend because time is tight, I had 10 minutes left over, but there were some questions I couldn&rsquo;t answer in the first round.&#xA;The test is divided into different sections, each with a different value, generally fluctuating around 20%.&#xA;At the end of the exam, the system automatically calculates your score and informs you if you approved. You need a minimum of 700 points out of a maximum of 1000 points to pass.&#xA;<h3 id="contents-of-the-az-900-exam">Contents of the AZ-900 exam</h3>&#xA;The exam is strongly oriented towards practical applications of cloud services. With questions focused on practical cases, where a fictitious company needs to decide which cloud service can best meet their needs, so it is not enough to know definitions, but to have a clear understanding of concepts, to be able to apply them in an environment a little more similar to the real one.&#xA;<h3 id="what-language-is-the-test-in">What language is the test in?</h3>&#xA;At the time of taking the exam it is possible to select from several languages, including English and Spanish, so don&rsquo;t worry if you think that language will be another barrier in this exam.&#xA;<h2 id="where-to-study-for-the-az-900-certification-exam">Where to study for the AZ-900 certification exam?</h2>&#xA;To study I used the following resources, here is a brief description of each one.&#xA;<h3 id="microsoft-learn">Microsoft Learn</h3>&#xA;The &#xA;&#xA;<a class="markdown-link" href="https://docs.microsoft.com/en-us/learn/" rel="noopener" target="_blank">microsoft Learn platform</a>&#xA; is the default resource, as there is no one better than microsoft to start reading the basic features of the Azure cloud. However, being a text-only solution it can become somewhat tedious. In addition, the large amount of information can make people who have their first approach to new technologies feel lost.&#xA;<a href="https://coffeebytes.dev/en/azure-az-900-certification-exam-my-experience/images/plataforma-microsoft-learn.jpg" aria-label="microsoft learn platform">&#xA;&#xA;<figure>&#xA; <img class="md-image" width="951" height="914" loading="lazy" src="https://coffeebytes.dev/en/azure-az-900-certification-exam-my-experience/images/plataforma-microsoft-learn.jpg" alt="microsoft learn platform"/>&#xA; <figcaption>microsoft learning platform</figcaption>&#xA;</figure>&#xA;&#xA;</a>&#xA;The e-learning platform is also available in Spanish, just select the language.&#xA;See below for details on the content of this platform.&#xA;<h3 id="learnbigdata">Learnbigdata</h3>&#xA;Aprenderbigdata has a &#xA;&#xA;<a class="markdown-link" href="https://aprenderbigdata.com/az-900-azure-fundamentals/" rel="noopener" target="_blank">exam guide in 5 PDF files</a>&#xA; quite complete with questions in Spanish, which you can use as a review quiz, it is almost at the bottom of the page.&#xA;<a href="https://coffeebytes.dev/en/azure-az-900-certification-exam-my-experience/images/aprender-big-data.jpg" aria-label="Learn big data">&#xA;&#xA; <img class="md-image" width="1194" height="666" loading="lazy" src="https://coffeebytes.dev/en/azure-az-900-certification-exam-my-experience/images/aprender-big-data.jpg" alt="Learn big data"/>&#xA;&#xA;</a>&#xA;<h3 id="adam-marczacs-website">Adam Marczac&rsquo;s website</h3>&#xA;The &#xA;&#xA;<a class="markdown-link" href="https://marczak.io/az-900/" rel="noopener" target="_blank">Marczac website</a>&#xA; has a complete review of the AZ-900 certification content, organized into sections, along with an interactive form where you can test your knowledge on the spot, plus links to their youtube videos. I highly recommend it.&#xA;&#xA;<div style="position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden;">&#xA; <iframe src="https://www.youtube.com/embed/NPEsD6n9A_I" style="position: absolute; top: 0; left: 0; width: 100%; height: 100%; border:0;" allowfullscreen title="YouTube Video"></iframe>&#xA;</div>&#xA;&#xA;<h3 id="technical-preparation-from-john-savill">Technical preparation from John Savill</h3>&#xA;Among the resources I used to study I would like to highlight the following video by John Savill, as I found it to be the most complete and best explained:&#xA;&#xA;<div style="position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden;">&#xA; <iframe src="https://www.youtube.com/embed/tQp1YkB2Tgs" style="position: absolute; top: 0; left: 0; width: 100%; height: 100%; border:0;" allowfullscreen title="YouTube Video"></iframe>&#xA;</div>&#xA;&#xA;It is a 3-hour review in English, in which they explain the basics of the Azure cloud, in a more structured and visual way. Like a giant blueprint of the cloud, in which they explain each part and how it relates to the others.&#xA;<h2 id="how-much-does-az-900-certification-cost-is-it-free">How much does AZ-900 certification cost? Is it free?</h2>&#xA;The certification costs about $90 USD directly with microsoft, but I got it for free as part of a &#xA;&#xA;<a class="markdown-link" href="https://platzi.com/r/eduardo-zepeda" rel="noopener" target="_blank">Platzi learning platform certification challenge</a>&#xA;.&#xA;I understand that if you sign up for the Microsoft Learn e-learning platform, they usually give away coupons from time to time.&#xA;With so many coupons and other free options, I don&rsquo;t recommend that you shell out the money out of pocket but wait for an opportunity to get it for free or much cheaper.&#xA;<h2 id="free-platzi-az-900-certification-process">Free Platzi AZ-900 certification process</h2>&#xA;A couple of months ago Platzi offered a challenge in which they give you the opportunity to certify yourself completely free of charge, through their platform, with two requirements: pass a series of courses on their platform, with their respective exams, and complete a Microsoft Learn practice lab.&#xA;<h3 id="required-platzi-courses">Required Platzi Courses</h3>&#xA;The process consists of completing the following 4 courses:&#xA;<ul>&#xA;<li>Fundamentals of Software Engineering</li>&#xA;<li>Introduction to the Terminal and Command Line Course</li>&#xA;<li>Linux Server Administration Course</li>&#xA;<li>Introduction to the Cloud with Azure Course</li>&#xA;</ul>&#xA;In general the first two are fairly easy, especially if you already have experience working with the &#xA;&#xA;<a class="markdown-link" href="https://coffeebytes.dev/en/linux-basic-commands-grep-ls-cd-cat-cp-rm-scp/">usual linux commands from the terminal</a>&#xA;, the last two do require some experience or a lot of practice on your part to pass them.&#xA;<a href="https://coffeebytes.dev/en/azure-az-900-certification-exam-my-experience/images/administracion-servidores-linux.jpg" aria-label="Platzi&amp;rsquo;s Linux Server Administration Course">&#xA;&#xA;<figure>&#xA; <img class="md-image" width="1283" height="801" loading="lazy" src="https://coffeebytes.dev/en/azure-az-900-certification-exam-my-experience/images/administracion-servidores-linux.jpg" alt="Platzi&amp;rsquo;s Linux Server Administration Course"/>&#xA; <figcaption>Linux Server Administration Course</figcaption>&#xA;</figure>&#xA;&#xA;</a>&#xA;<h3 id="microsoft-learn-practices">Microsoft Learn Practices</h3>&#xA;The practical laboratory is a series of 20 courses in which each course is subdivided into theory and practice. In the theoretical part you are shown the basics of the subject in written form, while the practical part consists of a short form of 3-4 questions in which the previous content is evaluated, but as a practical application.&#xA;For example, &ldquo;A company wants to implement a voting box where security is at its highest, which Microsoft Azure service would you recommend using.&rdquo;&#xA;<h2 id="azure-fundamentals-badge">Azure Fundamentals Badge</h2>&#xA;If you pass the exam, you will have access to the Microsoft AZ-900 Fundamentals badge, which you can register on Credly, or directly place your badge on a website, your LinkedIn profile or other medium.&#xA;This is mine, hosted on credly.&#xA;<figure><a href="https://www.credly.com/badges/17608a52-2cb7-4268-a907-613459559911/public_url"><img src="https://coffeebytes.dev/en/azure-az-900-certification-exam-my-experience/images%20microsoft-certified-azure-fundamentals.png"&#xA; alt="Azure AZ-900 certification badge by Eduardo Zepeda"/></a>&#xA;</figure>&#xA;&#xA;

On Saturday, August 6, 2022 I sat for and approved my Microsoft Azure AZ-900 certification exam.&#xA;What does AZ-900 certification consist of? The AZ-900 Fundamentals certification ensures that a person knows all the basic services that Microsoft&rsquo;s cloud, Azure, and its enterprise applications have.&#xA;For practical purposes, it prepares you to serve as an intermediary who recommends Microsoft Azure services to a company or third party, according to their needs. Or, as a software professional, you can take advantage of all the services that Azure has to offer.

Azure AZ-900 Certification Exam: My Experience

A sitemap is an xml file that functions as a map to navigate your site. Hence the name; Site-map. Search engines, such as google, bing, yahoo and others, use the sitemap of a site as a starting point to analyze its content and include it in their search results.&#xA;A sitemap is &#xA;&#xA;<a class="markdown-link" href="https://coffeebytes.dev/en/my-mistakes-regarding-the-tech-seo-optimization-of-my-website/">crucial in SEO and a sitemap with errors can plummet your site views</a>&#xA;, as it happened to me.&#xA;<h2 id="structure-of-a-sitemap">Structure of a sitemap</h2>&#xA;A sitemap is an xml file, which has an element called urlset, which is a collection of url elements. Each url element has a location, in this case its url address, a frequency of change, a priority and other optional elements, such as images.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-xml" data-lang="xml">&lt;?xml version=&#34;1.0&#34; encoding=&#34;UTF-8&#34;?&gt;&#xA;&lt;urlset xmlns=&#34;http://www.sitemaps.org/schemas/sitemap/0.9&#34; xmlns:xhtml=&#34;http://www.w3.org/1999/xhtml&#34;&gt;&#xA; &lt;url&gt;&#xA; &lt;loc&gt;http://example.com/objecto/1&lt;/loc&gt;&#xA; &lt;lastmod&gt;1970-01-01&lt;/lastmod&gt;&#xA; &lt;changefreq&gt;monthly&lt;/changefreq&gt;&#xA; &lt;priority&gt;0.8&lt;/priority&gt;&#xA; &lt;/url&gt;&#xA;&lt;/urlset&gt;&#xA;</code></pre></div><h3 id="split-sitemaps-for-simplicity">Split Sitemaps for simplicity</h3>&#xA;When a sitemap is very large it is possible to divide it into smaller sitemaps, using a sitemapindex element and sitemap sub elements, each with its respective location.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-xml" data-lang="xml">&lt;?xml version=&#34;1.0&#34; encoding=&#34;UTF-8&#34;?&gt;&#xA;&lt;sitemapindex xmlns=&#34;http://www.sitemaps.org/schemas/sitemap/0.9&#34;&gt;&#xA; &lt;sitemap&gt;&#xA; &lt;loc&gt;http://www.example.com/sitemap1.xml&lt;/loc&gt;&#xA; &lt;/sitemap&gt;&#xA; &lt;sitemap&gt;&#xA; &lt;loc&gt;http://www.example.com/sitemap2.xml&lt;/loc&gt;&#xA; &lt;/sitemap&gt;&#xA;&lt;/sitemapindex&gt;&#xA;</code></pre></div>But that&rsquo;s not all, you can divide it by category, by language or whatever fits the best for you.&#xA;<h2 id="framework-of-sitemaps-in-django">Framework of sitemaps in Django</h2>&#xA;Django already has an internal framework for sitemap generation, django.contrib.sitemaps, which allows us to create sitemaps dynamically in conjunction with django.contrib.sites.&#xA;django.contrib.sites is a framework included in django that allows you to manage different websites with the same django application.&#xA;To use the sitemaps framework, we need to add the two packages to the INSTALLED_APPS variable and also add the site identifier.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-python" data-lang="python"># settings.py&#xA;SITE_ID = 1&#xA;&#xA;INSTALLED_APPS = (&#xA; &#39;django.contrib.sites&#39;,&#xA; &#39;django.contrib.sitemaps&#39;,&#xA;)&#xA;</code></pre></div>Since Django keeps track of the sites that are managed by the application in the database, you will need to run migrations to update the database.&#xA;<h2 id="defining-a-sitemap-in-django">Defining a sitemap in Django</h2>&#xA;Now redirect to your application, at the same level as your models.py file and create a file called sitemaps.py.&#xA;Inside this file we are going to inherit a class from the Sitemap class provided by Django.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-python" data-lang="python"># app/sitemaps.py&#xA;from django.contrib.sitemaps import Sitemap&#xA;from .models import Videogame&#xA;&#xA;class VideogameSitemap(Sitemap):&#xA; changefreq = &#39;monthly&#39;&#xA; priority = 0.8&#xA;&#xA; def items(self):&#xA; return Videogame.objects.filter(published=True)&#xA;&#xA; def lastmod(self, obj):&#xA; return obj.modified&#xA;</code></pre></div><h3 id="items">items</h3>&#xA;By overwriting the items function we will define the queryset that will be used as a base, you can modify it as much as you want: partition it, limit it to attributes of your objects or as you prefer.&#xA;<h3 id="location">location</h3>&#xA;Location refers to the url of the resource. If we do not define a location method, Django will use the get_absolute_url method of our model to generate it.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-python" data-lang="python"># sitemaps.py&#xA;class VideogameSitemap(Sitemap):&#xA; # ...&#xA;&#xA; def location(self, obj):&#xA; return obj.customized_method()&#xA;</code></pre></div><h3 id="changefreq">changefreq</h3>&#xA;Refers to the frequency with which the content changes. You can use a function to generate it dynamically according to attributes of the object itself or leave it as a fixed value.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-python" data-lang="python"># app/sitemaps.py&#xA;class VideogameSitemap(Sitemap):&#xA;&#xA; def changefreq(self, obj):&#xA; # ...&#xA; return &#39;monthly&#39;&#xA;</code></pre></div><h3 id="priority">priority</h3>&#xA;It dictates the priority of the resource. It is possible to use a function to generate the priority dynamically through attributes or any other logic that you prefer.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-python" data-lang="python"># app/sitemaps.py&#xA;class VideogameSitemap(Sitemap):&#xA;&#xA; def priority(self, obj):&#xA; # ...&#xA; return 0.8&#xA;</code></pre></div><h2 id="adding-a-sitemap-to-django-urls">Adding a sitemap to Django urls</h2>&#xA;Now we have the sitemap, but we need to add it to the url in our project&rsquo;s urls.py file.&#xA;The view we will use, called sitemap, is provided by django and we just pass it a dictionary that relates to the sitemap we just created and pass it as a parameter.&#xA;Within the sitemaps variable you can add other sitemaps for other applications.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-python" data-lang="python">from django.contrib.sitemaps.views import sitemap&#xA;from videogame.sitemaps import VideogameSitemap&#xA;&#xA;sitemaps = {&#xA; &#39;videogames&#39;: VideogameSitemap,&#xA;}&#xA;&#xA;urlpatterns = [&#xA; # ...&#xA; path(&#39;sitemap.xml&#39;, sitemap, {&#39;sitemaps&#39;: sitemaps},&#xA; name=&#39;django.contrib.sitemaps.views.sitemap&#39;),&#xA;]&#xA;</code></pre></div><h2 id="setting-the-domain-name-for-the-sitemap-in-django-admin">Setting the domain name for the sitemap in Django admin</h2>&#xA;If we access the sitemap, you will notice that the base url of the urls is example.org, to define another one we need to modify the base from the administrator. The form is located at /admin/sites/site/&#xA;<a href="https://coffeebytes.dev/en/dynamic-sitemap-with-django/images/Django-sitio-sitemap.png" aria-label="Add a domain to the Django sitemap">&#xA;&#xA;<figure>&#xA; <img class="md-image" width="1291" height="528" loading="lazy" src="https://coffeebytes.dev/en/dynamic-sitemap-with-django/images/Django-sitio-sitemap.png" alt="Add a domain to the Django sitemap"/>&#xA; <figcaption>Modify the default domain of the sitemap in /admin/sites/site/</figcaption>&#xA;</figure>&#xA;&#xA;</a>&#xA;<h2 id="sitemap-cache">Sitemap cache</h2>&#xA;Remember that, generally, when you are creating a sitemap dynamically, from each of the objects in your database, you are going through it completely every time you access it. If your database is colossal, this may not be convenient because every access to the sitemap will hit the database, and trust me there are bots crawling the web several times a day.&#xA;Depending on the type of site you manage, you may want to store the sitemap in the &#xA;&#xA;<a class="markdown-link" href="https://coffeebytes.dev/en/caching-in-django-rest-framework-using-memcached/">Django cache</a>&#xA;.&#xA;

A sitemap is an xml file that functions as a map to navigate your site. Hence the name; Site-map. Search engines, such as google, bing, yahoo and others, use the sitemap of a site as a starting point to analyze its content and include it in their search results.&#xA;A sitemap is crucial in SEO and a sitemap with errors can plummet your site views , as it happened to me.

Dynamic sitemap with django

As you probably already know, you should not use prints for debugging. The standard go logging library is much more versatile, it adds dates, filenames and other information, plus you can redirect the logs to standard output, to a file or wherever you want. This can make your debugging process more enjoyable and &#xA;&#xA;<a class="markdown-link" href="https://coffeebytes.dev/en/go-basic-testing-and-coverage/">your go testing</a>&#xA; easier.&#xA;&#xA;&#xA;&#xA; <img width="60" height="60" src="https://res.cloudinary.com/dwrscezd2/image/upload/v1717959563/Go_gopher_favicon_uzxa20.svg" alt="">&#xA; <a target="_blank" rel=”nofollow” href="https://coffeebytes.dev/en/pages/go-programming-language-tutorial/">&#xA; Hey! did you know that I wrote a completely Free Go programming language tutorial?, you can find it directly in the top menu bar or clicking this box.</a>&#xA;&#xA;&#xA;<h2 id="log-println">Log Println</h2>&#xA;The log package is integrated into the standard logging library and its simplest function is Println which, for practical purposes, is like the standard Println but with some built-in benefits.&#xA;By default when logging something with go it will return the date and time, followed by the message we pass as an argument.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-go" data-lang="go">log.Println(&#34;Mensaje&#34;)&#xA;// 2022/06/28 13:38:25 Mensaje&#xA;</code></pre></div>The Println method of log behaves exactly like the &#xA;&#xA;<a class="markdown-link" href="https://coffeebytes.dev/en/go-functions-arguments-and-the-fmt-package/">fmt library</a>&#xA; method, so you can pass it multiple parameters and it will print them one by one.&#xA;<h2 id="flags-in-logging">Flags in logging</h2>&#xA;It is possible to change the default format in which the messages are displayed, change the order of the elements or add more information by calling the SetFlags method and passing it as arguments any of the flags provided by go.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-go" data-lang="go">log.SetFlags(log.Ldate | log.Lshortfile)&#xA;log.Println(&#34;Mensaje&#34;)&#xA;// 2022/06/28 main.go:10: Mensaje&#xA;</code></pre></div>There are more flags available in addition to the above two.&#xA;<h3 id="flags-available">Flags available</h3>&#xA;Flags are available to show the full path to our file, the line number or to move the prefix and place it before the message. I leave them below.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-go" data-lang="go">const (&#xA; Ldate = 1 &lt;&lt; iota &#xA; // Fecha en el tiempo local: 2009/01/23&#xA; Ltime &#xA; // Hora en el tiempo local: 01:23:23&#xA; Lmicroseconds &#xA; // Resolución en microsegundos: 01:23:23.123123. Asume Ltime.&#xA; Llongfile &#xA; // Ruta completa del archivo y número de linea: /a/b/c/d.go:23&#xA; Lshortfile &#xA; // Archivo y número de linea: d.go:23. Sobreescribe a Llongfile&#xA; LUTC &#xA; // Si ya están Ldate o Ltime usa UTC en lugar del tiempo local&#xA; Lmsgprefix &#xA; // Mueve el prefijo del principio de la linea y lo coloca antes del mensaje. &#xA; LstdFlags = Ldate | Ltime &#xA; // Los valores iniciales son Ldate y Ltime&#xA;)&#xA;</code></pre></div><h2 id="handling-errors-with-logging">Handling errors with logging</h2>&#xA;In addition to displaying information, it is possible to use methods, such as Panic and Fatal, to handle errors in our code.&#xA;<h3 id="logging-panic">Logging Panic</h3>&#xA;The log method has a Panic method that prints a message and calls the panic function.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-go" data-lang="go">log.Panic(&#34;El sistema se paniquea&#34;)&#xA;</code></pre></div>Panic has two variants:&#xA;<ul>&#xA;<li>Panicf: The equivalent of Printf, for formatting with position operators.</li>&#xA;<li>Panicln: The equivalent of Println</li>&#xA;</ul>&#xA;<h3 id="logging-fatal">Logging Fatal</h3>&#xA;If we want to terminate the execution of our program immediately, without allowing the system to recover, we have at our disposal the Fatal method.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-go" data-lang="go">log.Fatal(&#34;Error fatal ha ocurrido&#34;)&#xA;</code></pre></div>Like Panic, Fatal has two variants:&#xA;<ul>&#xA;<li>Fatalf: The equivalent of Printf, for formatting with position operators.</li>&#xA;<li>Fatalln: The equivalent of Println</li>&#xA;</ul>&#xA;<h2 id="redirecting-logging-output">Redirecting logging output</h2>&#xA;As I mentioned before, the library allows us to redirect, through its SetOutput method, the output of our logging to a destination; either the Stdout, the Stderr, the Stdin or even a file.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-go" data-lang="go">log.SetOutput(os.Stdout)&#xA;</code></pre></div>In the example above we are redirecting it to the standard output.&#xA;<h3 id="redirecting-to-a-file">Redirecting to a file</h3>&#xA;To redirect our logs to a file, we first need to create it and then pass it as an argument to the SetOutput method, after that, all our logs will be written to our file and we will be able to retrieve them later.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-go" data-lang="go">file, _ := os.Create(name: &#34;programa.log&#34;)&#xA;log.SetOutput(file)&#xA;log.Println(&#34;Mensaje a archivo&#34;)&#xA;file.Close()&#xA;</code></pre></div><h2 id="customized-loggers">Customized loggers</h2>&#xA;The log package allows us to create different types of loggers, using the New method, this method receives the following arguments; first, the destination of our logs, as you saw, this can be to the Stdout, the Stderr, the Stdin or a file; second, the prefix to show in each message; third, the flags with which we want to format our logs.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-go" data-lang="go">infoLogger := log.New(os.Stdout, prefix: &#34;INFO: &#34;, flags)&#xA;</code></pre></div>Once our log is created, we can call its Println method to display it in the standard output.&#xA;<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-go" data-lang="go">infoLogger.Println(&#34;Este es un mensaje de info&#34;)&#xA;</code></pre></div>

As you probably already know, you should not use prints for debugging. The standard go logging library is much more versatile, it adds dates, filenames and other information, plus you can redirect the logs to standard output, to a file or wherever you want. This can make your debugging process more enjoyable and your go testing easier.&#xA;Hey! did you know that I wrote a completely Free Go programming language tutorial?

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