Create a staging workflow

[github-learning-lab]

Welcome to the course!

We'll learn how to create a workflow that enables Continuous Delivery. You'll:

• create a workflow to deploy to staging based on a label
• create a workflow to deploy to production based on merging to main

Before you start, you should be familiar with GitHub and Continuous Integration. If you aren't sure where to start, you may want to check out these two Learning Lab courses:

• Introduction to GitHub
• Continuous Integration with GitHub Actions

What is Continuous Delivery?

Martin Fowler defined Continuous Delivery very simply in a 2013 post as follows:

Continuous Delivery is a software development discipline where you build software in such a way that the software can be released to production at any time.

A lot of things go into delivering "continuously". These things can range from culture and behavior to specific automation. In this course, we're going to focus on deployment automation.

Setting up environments and kicking off deployments

Automation works at its best when a set of triggers work harmoniously to set up and deploy to target environments. Engineers at many companies, like at GitHub, typically use a ChatOps command as a trigger. The trigger itself isn't incredibly important.

In our use case, we'll use labels as triggers for multiple tasks:

• When someone applies a "spin up environment" label to a pull request, that'll tell GitHub Actions that we'd like to set up our resources on an Azure environment.
• When someone applies a "stage" label to a pull request, that'll be our indicator that we'd like to deploy our application to a staging environment.
• When someone applies a "destroy environment" label to a pull request, we'll tear down any resources that are running on our Azure account.

For now, we'll focus on staging. We'll spin up and destroy our environment in a later step.

Step 1: Configure a trigger based on labels

In a GitHub Actions workflow, the on step defines what causes the workflow to run. In this case, we want the workflow to run whenever a label is applied to the pull request.

⌨️ Activity: Configure the workflow trigger based on a label being added

1. Edit the deploy-staging.yml file on this branch, or use this quick link (We recommend opening the quick link in another tab)
2. Change the name of the directory CHANGETHIS to workflows, so the title of this file with the path is .github/workflows/deploy-staging.yml. If you're working on the GitHub.com user interface, see the suggestion below for how to rename.
3. Edit the contents of this file to trigger a job called build on a label

Changing the name of a directory

If you're working locally, rename your file or drag-and-drop the file into the proper directory as you'd normally do. If you're working on GitHub.com, you can change the name of a directory by changing its filename and using the Backspace key until you reach the directory, as follows:

1. In the file name field, click in front of the first character in the file name
2. Press Backspace or Delete on your keyboard until you see the path you want to keep. You can continue to press Backspace even if the text box with the file name is empty.
3. Enter the new name for your directory.
4. Enter / to let GitHub know this should be a new directory.

Your resulting file should be in .github/workflows/deploy-staging.yml and it should look like this:

name: Stage the app

on: 
  pull_request:
    types: [labeled]

jobs:
  build:
    runs-on: ubuntu-latest

---

I'll respond when you push a commit on this branch.