Automating Deployment with GitHub Actions
This blog used to be automatically built and deployed via CircleCI. I had spent the time setting up the pipelines so that I could ensure that deployment of new versions was as easy as merging a pull request. I was happy with the results, everything was working. This continued for a few years, I never consider making changes to the workflow. Eventually, however, I began receiving emails informing me that my implementation based on Version 1 of the CircleCI configuration system would need to be migrated to the latest-and-greatest Version 2 of their system. At this time I was in the middle of a busy season in my life, and despite good communication from the CircleCI team and what I’m sure is a very usable Version 2 system I never managed to get around to migrating my configuration. Eventually my inaction led to the deactivation of the integration I had set up. I want to be very clear that this is not CircleCI’s fault, it is mine and mine alone.
At the time of writing this deactivation happened a few years ago. In the meantime I’ve still been writing and publishing, deploying manually. Luckily my build and deploy workflow is simple: a single node command to build, and an rsync command to deploy. Still, I always have intended on re-automating those steps. I am a proponent of the power of automation in my professional circles, I ought to practice what I preach in my personal projects as well as my professional ones.
I’ve been putting this off for a long time, a primary reason being that I wasn’t sure what system I wanted to use. Since I had last done the research around providers of CI services the landscape has changed dramatically, and I’d been exposed to a number of them. I’ve used CircleCI, Bitrise, GitLab’s CI system, Jenkins, and some very rudimentary home-rolled shell scripts combined with git hooks. A notable gap in my stable of experiences was GitHub Actions. I’d heard positive testimonials from my peers, so when I finally took the time to re-enable a more sustainable deployment system I decided to take the opportunity to fill that gap and explore GitHub Actions.
Right away, reading the introduction to the GitHub Actions model showed some promising attributes:
Price. Since I operate this blog as an open-source project, using GitHub Actions is free!
Integration with GitHub. Somewhat obvious, but having a one-stop-shop for my entire writing and development workflow is attractive and minimizes the number of systems I need to keep track of over time.
Simplicity. I want to focus on writing my content, not building CI systems. I know that being well-versed in DevOps topics makes me a more well-rounded professional, but for something as simple as this blog I’m highly attracted to a CI system that will get out of my way.
I started by creating a directory in the root of my project:
.github/workflows/, as specified in this documentation. I began by giving my workflow a name:
Node.js CI. I only wanted this workflow to run when code hits my
master branch, so I used the
on: specification at the top of my configuration file:
Now that I had specified when to run, I needed to describe what actions to take. I decided to split my process into two jobs: one for generating static HTML files from the markdown files that I use to write my posts, and another for pushing these generated files to the server hosting this site. To build, I used the following configuration:
This specification tells GitHub Actions via the
runs-on statement to use Ubuntu, then specifies that Node.js version 12 should be used for the build process. I chose these settings to match my development environment. The
steps portion of the configuration file begins with a
uses command, which takes advantage of the GitHub-provided checkout action to obtain the latest version of the source code. I follow this up using the
setup-node action to automatically configure the ubuntu environment for use with Node.js. This action installs Node.js, sets the PATH variable within the Ubuntu container, and ensures that the container is configured as similarly as possible to my development environment. After that, I invoke
run, passing down a pair of shell commands to be run. The first of these commands installs dependencies based on the packages specified in
package.json using the standard
npm install. The command that follows generates the HTML site content from the source markdown, placing it in the
public/ directory. The final set of commands in the building process takes the production artifacts created by the run command from under the
public/ directory and uploads them to the GitHub artifact system, enabling them to be downloaded later by the publish job. This upload is facilitated by GitHub’s
The publish job starts up when the build job finishes, and is configured as seen here:
Similar to the build job, I use Ubuntu to run the publish job. To ensure that the publish job runs after the build job, and not in parallel, I use
needs and name the build job as a prerequisite for the publish job. This is critical, since without a successful build job we won’t have any artifacts saved to publish. Since we know that these artifacts have been saved and stored, we start by using the
download-artifact action to grab the result recorded by the previous job. I wanted to make sure that I had a record of when the code was last deployed, so I added a timestamp file to the process by calling the standard unix
date command, piped into a file under the
public/ directory; this entire directory will be uploaded to the web server hosting my site. The contents of this file ensures that I have a convenient, if crude, manner of checking to ensure that deployments succeeded when I make changes that are not plainly visible. I then finish the process by using a community developed action,
rsync-deployments to push the contents of the
public/ directory to my server. The sensitive information needed to complete the rsync process is set in the GitHub web UI, and is accessed as simple key-value pairs in the actions configuration file by calling
secrets.KEY. In the case of my rsync deployment process I needed the IP address of the server, a user on said server, and an SSH key. Different use cases might need other secrets, but the access mechanism is the same.
Once I had all this in place running a first deployment was as simple as committing the configuration file and pushing to my
master branch. The Actions workflow kicked in, running as I expected and publishing a new version of my site in under a minute. I confirmed this deployment by checking that the timestamp file that I had set up had changed, pleased to find that it was successful. Since the repository is open source, interested readers can take a look at the latest runs of this CI workflow here.
This miniture project was a resounding success. The process took me about an hour from start to finish, I was impressed by the documentation provided by GitHub, and especially thankful for the community packages that were provided. I’m happy to say that I’ve now had exposure to the GitHub Actions system, and will keep it in the forefront of my mind going forward as a strong candidate for any occasion where I need to automate actions within a GitHub-based project.