🔥Let’s Do DevOps: Terraform GitHub Action Targeting from Web Console User Input

Kyler Middleton
7 min readSep 15, 2022

This blog series focuses on presenting complex DevOps projects as simple and approachable via plain language and lots of pictures. You can do it!

Hey all!

I’m helping a team migrate their automation from AWS CodeBuild into GitHub Actions, including Terraform automation. CodeBuild is relatively clunky, but it has something useful that is absolutely critical to this team — you can run a pipeline and target a specific version of your source code — a branch or tag.

Until recently GitHub Actions didn’t support this — they are strong proponents of GitOps, where pure git actions drive all automation, and user input isn’t gathered. However, that has changed!

You can set all sorts of inputs on your action, like.. um, how many octocats to build, and their eye color (?!)

Actions now support both workflow_dispatch (launching an action manually from the web console) and inputs, a way of gathering input from the user when launching an action. We can combine these to have highly dynamic Actions.

Let’s walk through my implementation of a Terraform validation and deploy Action that takes input on launch of:

  • Branch/tag target
  • Custom field: Environment and Region of AWS to target

Gathering Action Inputs

The first part of our pipeline names it, and then immediately gathers some inputs. Line 1 names our pipeline. Line 3, on:, is where we’d normally set the triggers for our pipeline, line on_push and filters like the path of files changes.

Here, instead, we set a trigger of workflow_dispatch, which means this action will be triggerable from the github web page console. We set an input called “environment” and add custom fields for description, set it required (line 10), and set some options (line 11). I made up the options on line 11 — put whatever you’d like! This will appear as a required drop-down when launching this pipeline from the web console.

Kyler Middleton

DevNetSecOps, DevRel, cloud security chick. I will teach you, it’s unavoidable. She/Her 🏳️‍🌈🏳️‍🌈, INFJ-A, support the EFF!