In my previous post I presented how I built a simple static blog generator from the ground up. My goal was to use it when writing my own blog as a replacement for the default Github Pages generator, Jekyll. I wanted to make publishing a new post as simple as a git push so I've created some CI/CD workflows in Github Actions.
First, I wanted my generator software to be released every time when I push a tag with a v*.*.* schema. For that purpose I needed two predefined action:
You can see the whole workflow file on the project github, I'd only highlight some key steps from it.
This part esures that workflow is only triggered when a tag is pushed with a semantic version number prefixed with 'v'.
on:
push:
tags:
- 'v*.*.*'
Github actions have only a $GIHUB_REF environment variable that contains the full ref path so you have to get the substring of it:
- name: Set env
run: echo ::set-env name=RELEASE_VERSION::${GITHUB_REF:10}
That way the pure tag name can be used as env.RELEASE_VERSION later.
Since user pages must be published from master branch I chose to host my blog source in a separate repository and automate it to render the blog html-s when an update is pushed to it. I also made a separate repository for the template that can trigger a blog build when updated through a repository_dispatch event with curl.
You can see the full code here.
This is the trigger part:
on:
push:
branches: [ master ]
repository_dispatch:
types: trigger-ci
This line clones the template repository to the directory defined by config.
- name: Checkout clean-blog template
shell: bash
run: git clone https://github.com/codernr/startbootstrap-clean-blog.git templates/clean-blog
This script reads the latest release url from Github API, then downloads and unpacks it.
- name: Download latest Bloggen.Net
shell: bash
run: |
latest_data=$(curl -s "https://api.github.com/repos/codernr/bloggen-net/releases/latest")
download_url=$(egrep -oh -m 1 "(https://github.com/codernr/bloggen-net/releases/download/v[0-9]\.[0-9]\.[0-9]/v[0-9]\.[0-9]\.[0-9]\.tar\.gz)" <<< $latest_data)
curl -L $download_url --output bloggen-net.tar.gz
tar -zxvf bloggen-net.tar.gz
This part creates the html site in the bloggen-output folder.
- name: Generate site
shell: bash
run: |
cd deploy
dotnet Bloggen.Net.dll -s "${PWD}/../" -o bloggen-output
This part clones the main user page repository, overwrites the files in it with the new generated ones and pushes to the master branch of https://codernr.github.io repository.
- name: Update blog repository
shell: bash
env:
GITHUB_TOKEN: ${{ secrets.GithubToken }}
USER_MAIL: ${{ secrets.Mail }}
run: |
cd deploy
git clone "https://codernr:${GITHUB_TOKEN}@github.com/codernr/codernr.github.io.git"
rm -rf codernr.github.io/*/ codernr.github.io/*.html
cp -rf bloggen-output/* codernr.github.io/
cd codernr.github.io
git config user.name codernr
git config user.email $USER_MAIL
git add --all
git commit -am "Automatic github pages update from blog-source CI"
git push
And that's it, the page is published!
I'm constantly developing the generator software and the template along with it so I also wanted an automation mechanism to update the blog when I update the template. So I made the repository_dispatch trigger for the workflow described in the previous section, that is triggered by the template action when changes are pushed to master. It then posts the proper json to Github API to trigger the specified event (trigger-ci).
You can read more about this event here.
And this is the workflow that sends the event:
name: CI
on:
push:
branches: [ master ]
jobs:
webhook:
runs-on: ubuntu-latest
steps:
- name: Dispatch update event
shell: bash
env:
GITHUB_TOKEN: ${{ secrets.BlogSourceToken }}
run: |
curl -H "Accept: application/vnd.github.everest-preview+json" \
-H "Authorization: token ${GITHUB_TOKEN}" \
--request POST \
--data '{"event_type": "trigger-ci"}' \
https://api.github.com/repos/codernr/blog-source/dispatches
If you have any interesting experiences or questions about this field, let me know in the comments!