Merge pull request #1 from trussworks/cht-implement-functionality

Merge full functionality

.eslintrc.json

@@ -0,0 +1,18 @@
+{
+  "env": {
+      "commonjs": true,
+      "es6": true,
+      "node": true,
+      "jest": true
+  },
+  "extends": "eslint:recommended",
+  "globals": {
+      "Atomics": "readonly",
+      "SharedArrayBuffer": "readonly"
+  },
+  "parserOptions": {
+      "ecmaVersion": 2018
+  },
+  "rules": {
+  }
+}

.gitignore

@@ -0,0 +1,2 @@
+node_modules/
+

.pre-commit-config.yaml

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+repos:
+  - repo: git://github.com/pre-commit/pre-commit-hooks
+    rev: v4.0.1
+    hooks:
+      - id: check-merge-conflict
+      - id: detect-private-key
+      - id: trailing-whitespace
+
+  - repo: git://github.com/igorshubovych/markdownlint-cli
+    rev: v0.28.1
+    hooks:
+      - id: markdownlint

README.md

@@ -1 +1,52 @@
-# ecs-scaledown
+# ecs-scaledown
+
+The purpose of this repository is to provide a GitHub Action to
+scale down an ECS service's desired count to zero.
+
+This action leverages the
+ aws-actions/configure-aws-credentials action.
+ Since GitHub Actions currently does not allow
+ composite actions to call other actions,
+ we chose to integrate the JavaScript code from existing aws-actions into this repository.
+
+## What it does
+
+1. Configure AWS credentials. Uses existing action:
+ [aws-actions/configure-aws-credentials](https://github.com/aws-actions/configure-aws-credentials)
+2. Uses the AWS SDK for JavaScript to decrement the
+ specified ECS Service's `desired count` attribute to 0.
+
+## Modifications made to existing AWS actions
+
+No modifications made. the `index.js` and `cleanup.js` files from
+ the configure-aws-credentials action were copied into
+  `src/main/configAwsCreds.js` and `src/cleanup/configAwsCreds.js`.
+
+## Use Case and Usage
+
+This action was developed as a way to scale down
+ an ECS Service after the tasks no longer need to be run.
+Specifically, this is designed to work following a workflow using
+ Self-Hosted GitHub Runners that are stood up by
+  the [trussworks/ecs-scaleup](https://github.com/trussworks/ecs-scaleup) action.
+
+```yaml
+ecs-scaledown:
+  name: Scale down ECS Service
+  needs: [ecs-scaleup, ALL_OTHER_JOBS]
+  runs-on: ubuntu-latest
+  steps:
+    - name: ecs-scaledown
+      uses: trussworks/ecs-scaledown
+      with:
+        aws-access-key-id: ${{ secrets.AWS_ACCESS_KEY_ID }}
+        aws-secret-access-key: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
+        aws-region: "us-east-1"
+        service: github-actions-runner
+        cluster: github-runner
+```
+
+**NOTE**: When using this to deprovision Self-Hosted GitHub runners,
+ you must populate the `needs` argument in the YAML above with
+  all jobs that are using self-hosted runners.
+   To do this, replace ALL_OTHER_JOBS with a list of jobs denoted by name.

action.yml

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+name: 'Deprovision GitHub Runners'
+description: 'Scale down ECS service count'
+inputs:
+  aws-access-key-id:
+    description: >-
+      AWS Access Key ID. This input is required if running in the GitHub hosted environment.
+      It is optional if running in a self-hosted environment that already has AWS credentials,
+      for example on an EC2 instance.
+    required: false
+  aws-secret-access-key:
+    description: >-
+      AWS Secret Access Key. This input is required if running in the GitHub hosted environment.
+      It is optional if running in a self-hosted environment that already has AWS credentials,
+      for example on an EC2 instance.
+    required: false
+  aws-region:
+    description: 'Your AWS region'
+    required: true
+    default: 'us-east-1'
+  service:
+    description: 'The name of the ECS service.'
+    required: true
+  cluster:
+    description: 'The name of the ECS cluster the service belongs to.'
+    required: true
+runs:
+  using: 'node12'
+  main: 'dist/index.js'
+  post: 'dist/cleanup/index.js'