After the post where I explained how to create a README for the GitHub profile, I missed including in the section of the Blog a link to the last post published. I mainly didn’t because I didn’t want to have to manually update the README every time with the last post and its link. To solve this I was thinking how I could automate this update. While doing my daily reading of the RSS feeds I follow with the Feedly app, I stumbled upon that I also had RSS feeds. So I could read my blog feed myself and get the latest post from there easily.

Once I covered the part of how to get the last post published, I missed the part of how to update the README and that’s where I first tried (I had been wanting for a long time) the GitHub Actions. Some time ago GitHub launched these actions that basically serve to create automatic workflows for CI/CD.

With both parts of the problem covered, I was just missing a little thing… do it! So I will explain in detail how I did both so you can use it in your project if you are interested.

Get the latest post with Go

I needed to scan the blog feed and wanted to do it in Go, so the first thing I did was look for any libraries that would make it easier for me not to reinvent the wheel and I found the github.com/mmcdole/gofeed. It had a lot of features but I had enough with the basic use described in its README.

With the next piece of code, I create a new parser, scan the address of my feed and the resulting items, I save only the first one, as it is the last post posted.

p := gofeed.NewParser()
feed, err := p.ParseURL("https://charly3pins.dev/index.xml")
if err != nil {
    log.Fatalf("error getting feed: %v", err)
}
newestItem := feed.Items[0]

With that I already have the item with all the information. It looks like:

<item>
    <title>My productivity setup for VS Code</title>
    <link>http://charly3pins.dev/blog/my-productivity-setup-for-vs-code/</link>
    <pubDate>Tue, 09 Mar 2021</pubDate>
    <guid>http://charly3pins.dev/blog/my-productivity-setup-for-vs-code/</guid>
    <description>I am gonna show you my setup for VS Code editor which makes me more productive and I feel more comfortable with the tool that I spend most of my time during the day.</description>
    <content><p>I spend a lot of hours during the day coding for the company I work for and during nights or weekends for myself, so I want to be comfortable with the tools I use constantly. One of them is my editor of code, specifically <a href="https://code.visualstudio.com/">VS Code</a>.....</content>
</item>

What I’m interested in showing in README is just the title and the link.

Read and write the README

Once I had the necessary information I now had to read the README.md file from the repository, write the changes and save it again.

To do this I could read the file using the standard library ioutil.ReadFile(), but in this case since I don’t want to reuse anything from the file, so I can call os.Create() directly to create a new file and so overwrite the README.md that I already had in the directory.

Also, since I want to put the feed information along with the static part of text I already had, what I will do is create a few strings with the different sections I want to put in the profile and then put them all together using fmt.Sprintf().

The code that does all this is this:

file, err := os.Create(filename)
if err != nil {
	log.Println("error creating file", err)
	return
}
defer file.Close()

_, err = io.WriteString(file, data)
if err != nil {
	log.Println("error writing content to file", err)
	return
}
file.Sync()

What remains to be seen from here is the value of filename and that of data. The first is easy, just the route to get to the README. In my case as I have the project in a subdirectory of my repository I have to use filename = ../README.md. For the other variable, what is there is this:

hi := "# Hey there!"
blog := "## Blog\n\nMy latest blog post is: **[" + newestItem.Title + "](" + newestItem.Link + ")**."

data := fmt.Sprintf("%s\n\n%s\n\n%s\n\n%s\n", hi, blog)

The important part is the blog where you can clearly see how I read the feed information.

You can see the complete code in my repository.

Running the process automatically

Once we have the code that generates the README automatically and dynamically according to the last post, what remains to be done is to run it periodically and in order to do not have to worry about anything. To do this I will use a trigger from GitHub Actions so that every time I push to branch master run the process and also run it on a scheduled basis every Sunday at 12am.

First of all I need the .github/worfklows folder and inside I create the update.yaml file with the following content:

on:
  push:
    branches:
      - master
  schedule:
    - cron: '0 0 * * 0'

Once the trigger is ready, what needs to be defined are the jobs. You can define as many as you want, in my case with 3 I have enough. The first will checkout the project, the second will generate the README, and the third will deploy the changes. For the last step we will need to use the authentication mechanisms provided by GitHub Actions. The resulting code is:

jobs:
  build-and-deploy:
    runs-on: ubuntu-latest

    steps:
      - name: checkout repo
        uses: actions/checkout@master
        with:
          fetch-depth: 1
      - name: generate README
        run: |
          cd ${GITHUB_WORKSPACE}/update/
          go run main.go
      - name: deploy changes
        run: |
          git config user.name "${GITHUB_ACTOR}"
          git config user.email "${GITHUB_ACTOR}@users.noreply.github.com"
          git add .
          git commit -am "🚀: updated content"

You can see the full code in my repository.

Feel free to comment here or contact me on my social media for any comments, questions or suggestions.