Merge pull request #9 from appvia/monorepo

Adding plan only workflow

.github/workflows/terraform-plan-aws.yml

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+## Plan only workflow for testing purposes. Allows working directory 
+# distinction to test with different modules.
+
+name: Terraform Validate and Plan
+on:
+  workflow_call:
+    secrets:
+      infracost-api-key:
+        description: 'The API key for infracost'
+        required: false
+    inputs:
+      aws-account-id:
+        description: 'The AWS account ID to deploy to'
+        required: true
+        type: number
+      aws-role-name-readonly:
+        default: '${{ github.event.repository.name }}-ro'
+        description: 'The Read Only AWS role to assume for PR branch executions'
+        required: false
+        type: string
+      aws-role-name-readwrite:
+        default: '${{ github.event.repository.name }}-rw'
+        description: 'The Read/Write AWS role to assume for main branch executions'
+        required: false
+        type: string
+      aws-region:
+        default: 'eu-west-2'
+        description: 'The AWS region to deploy to'
+        required: false
+        type: string
+      enable-infracost:
+        default: false
+        description: 'Whether to run infracost on the Terraform Plan (secrets.infracost-api-key must be set if enabled)'
+        required: false
+        type: boolean
+      runs-on:
+        default: "ubuntu-latest"
+        description: 'Single label value for the GitHub runner to use (custom value only applies to Terraform Plan and Apply steps)'
+        required: false
+        type: string
+      terraform-log-level:
+        default: ''
+        description: 'The log level of terraform'
+        required: false
+        type: string
+      terraform-state-key:
+        default: '${{ github.event.repository.name }}.tfstate'
+        description: 'The key of the terraform state'
+        required: false
+        type: string
+      terraform-values-file:
+        default: 'values/production.tfvars'
+        description: 'The values file to use'
+        required: false
+        type: string
+      terraform-version:
+        default: '1.5.7'
+        description: 'The version of terraform to use'
+        required: false
+        type: string
+      working-directory:
+        default: '.'
+        description: 'Working directory'
+        required: false
+        type: string
+
+
+env:
+  TF_LOG: ${{ inputs.terraform-log-level }}
+  AWS_WEB_IDENTITY_TOKEN_FILE: /tmp/web_identity_token_file
+
+permissions:
+  id-token: write
+  contents: read
+  pull-requests: write
+
+jobs:
+  terraform-format:
+    name: "Terraform Format"
+    runs-on: ubuntu-latest
+    defaults:
+        run:
+          working-directory: ${{ inputs.working-directory }}
+    outputs:
+      result: ${{ steps.format.outcome }}
+    steps:
+      - name: Checkout Repository
+        uses: actions/checkout@v3
+      - name: Setup Terraform
+        uses: hashicorp/setup-terraform@v2
+        with:
+          terraform_version: ${{ inputs.terraform-version }}
+      - name: Terraform Format
+        id: format
+        uses: dflook/terraform-fmt-check@v1
+  terraform-lint:
+    name: "Terraform Lint"
+    runs-on: ubuntu-latest
+    defaults:
+        run:
+          working-directory: ${{ inputs.working-directory }}
+    outputs:
+      result: ${{ steps.lint.outcome }}
+    steps:
+      - name: Checkout Repository
+        uses: actions/checkout@v3
+      - name: Setup Linter
+        uses: terraform-linters/setup-tflint@v3
+      - name: Linter Initialize
+        run: tflint --init
+      - name: Linting Code
+        id: lint
+        run: tflint -f compact
+  terraform-plan:
+    name: "Terraform Plan"
+    if: github.event_name == 'pull_request' || (github.event_name == 'push' && github.ref == 'refs/heads/main')
+    runs-on: ${{ inputs.runs-on }}
+    defaults:
+        run:
+          working-directory: ${{ inputs.working-directory }}
+    outputs:
+      result-auth: ${{ steps.auth.outcome }}
+      result-init: ${{ steps.init.outcome }}
+      result-validate: ${{ steps.validate.outcome }}
+      result-s3-backend-check: ${{ steps.s3-backend-check.outcome }}
+      result-plan: ${{ steps.plan.outcome }}
+      plan-stdout: ${{ steps.plan.outputs.stdout }}
+    steps:
+      - name: Checkout Repository
+        uses: actions/checkout@v3
+      - name: Setup node
+        uses: actions/setup-node@v3
+        with:
+          node-version: 16
+      - name: Setup Terraform
+        uses: hashicorp/setup-terraform@v2
+        with:
+          terraform_version: ${{ inputs.terraform-version }}
+      - name: Retrieve Web Identity Token for AWS Authentication
+        run: |
+          curl -H "Authorization: bearer $ACTIONS_ID_TOKEN_REQUEST_TOKEN" "$ACTIONS_ID_TOKEN_REQUEST_URL&audience=sts.amazonaws.com" | jq -r '.value' > $AWS_WEB_IDENTITY_TOKEN_FILE
+      - name: Determine AWS Role
+        id: role
+        run: |
+          if [[ "${GITHUB_REF##*/}" == "main" ]]; then
+            echo "name=${{ inputs.aws-role-name-readwrite }}" >> $GITHUB_OUTPUT
+          else
+            echo "name=${{ inputs.aws-role-name-readonly }}" >> $GITHUB_OUTPUT
+          fi
+      - name: Authenticate with AWS
+        id: auth
+        uses: aws-actions/configure-aws-credentials@v2
+        with:
+          aws-region: ${{ inputs.aws-region }}
+          role-session-name: ${{ github.event.repository.name }}
+          role-to-assume: arn:aws:iam::${{ inputs.aws-account-id }}:role/${{ steps.role.outputs.name }}
+          mask-aws-account-id: 'no'
+      - name: Terraform Init
+        id: init
+        run: terraform init -backend-config="bucket=${{ inputs.aws-account-id }}-${{ inputs.aws-region }}-tfstate" -backend-config="key=${{ inputs.terraform-state-key }}" -backend-config="encrypt=true" -backend-config="dynamodb_table=${{ inputs.aws-account-id }}-${{ inputs.aws-region }}-tflock" -backend-config="region=${{ inputs.aws-region }}"
+      - name: Terraform Validate
+        id: validate
+        run: terraform validate -no-color
+      - name: Terraform S3 Backend Check
+        id: s3-backend-check
+        run: |
+          if grep -E '^[^#]*backend\s+"s3"' terraform.tf; then
+            echo "Terraform configuration references an S3 backend."
+          else
+            echo "Terraform configuration does not reference an S3 backend."
+            exit 1
+          fi
+      - name: Terraform Plan
+        id: plan
+        run: |
+          terraform plan -var-file=${{ inputs.terraform-values-file }} -no-color -input=false -out=tfplan
+      - name: Terraform Plan JSON Output
+        run: |
+          terraform show -json tfplan > tfplan.json
+      - name: Upload tfplan
+        uses: actions/upload-artifact@v3
+        with:
+          name: tfplan
+          path: "tfplan*"
+          retention-days: 1
+  get-cost-estimate:
+    name: "Get Cost Estimate"
+    if: github.event_name == 'pull_request' && inputs.enable-infracost
+    runs-on: ubuntu-latest
+    defaults:
+        run:
+          working-directory: ${{ inputs.working-directory }}
+    needs:
+      - terraform-plan
+    steps:
+      - name: Setup Infracost
+        uses: infracost/actions/setup@v2
+        with:
+          api-key: ${{ secrets.infracost-api-key }}
+          currency: GBP
+      - name: Download tfplan
+        uses: actions/download-artifact@v3
+        with:
+          name: tfplan
+      - name: Generate Infracost Cost Estimate
+        run: |
+          infracost breakdown --path=tfplan.json \
+            --format=json \
+            --out-file=/tmp/infracost.json
+      - name: Post Infracost comment
+        run: |
+          infracost comment github --path=/tmp/infracost.json \
+            --repo=$GITHUB_REPOSITORY \
+            --github-token=${{github.token}} \
+            --pull-request=${{github.event.pull_request.number}} \
+            --behavior=update
+
+  update-pr:
+    name: "Update PR"
+    if: github.event_name == 'pull_request' && (success() || failure())
+    runs-on: ubuntu-latest
+    needs:
+      - terraform-format
+      - terraform-lint
+      - terraform-plan
+    steps:
+      - name: Add PR Comment
+        uses: actions/github-script@v6
+        env:
+          PLAN: "${{ needs.terraform-plan.outputs.plan-stdout }}"
+        with:
+          script: |
+            // 1. Retrieve existing bot comments for the PR
+            const { data: comments } = await github.rest.issues.listComments({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: context.issue.number,
+            })
+            const botComment = comments.find(comment => {
+              return comment.user.type === 'Bot' && comment.body.includes('Pull Request Review Status')
+            })
+
+            // 2. Check output length
+            const PLAN = process.env.PLAN || '';
+            const excludedStrings = ["Refreshing state...", "Reading...", "Read complete after"];
+            const filteredLines = PLAN.split('\n').filter(line =>
+              !excludedStrings.some(excludedStr => line.includes(excludedStr))
+            );
+            var planOutput = filteredLines.join('\n').trim();
+            if (planOutput.length < 1 || planOutput.length > 65000) {
+              planOutput = "Terraform Plan output is too large, please view the workflow run logs directly."
+            }
+
+            // 3. Prepare format of the comment
+            const output = `### Pull Request Review Status
+            * 🖌 <b>Terraform Format and Style:</b> \`${{ needs.terraform-format.outputs.result }}\`
+            * 🔍 <b>Terraform Linting:</b>          \`${{ needs.terraform-lint.outputs.result }}\`
+            * 🔑 <b>AWS Authentication:</b>         \`${{ needs.terraform-plan.outputs.result-auth }}\`
+            * 🔧 <b>Terraform Initialisation:</b>   \`${{ needs.terraform-plan.outputs.result-init }}\`
+            * 🤖 <b>Terraform Validation:</b>       \`${{ needs.terraform-plan.outputs.result-validate }}\`
+            * 📁 <b>Terraform S3 Backend:</b>       \`${{ needs.terraform-plan.outputs.result-s3-backend-check }}\`
+            * 📖 <b>Terraform Plan:</b>             \`${{ needs.terraform-plan.outputs.result-plan }}\`
+
+            <details><summary><b>Output: 📖 Terraform Plan</b></summary>
+
+            \`\`\`
+            ${planOutput}
+            \`\`\`
+            </details>
+
+            *<b>Pusher:</b> @${{ github.actor }}, <b>Action:</b> \`${{ github.event_name }}\`*
+            *<b>Workflow Run Link:</b> ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}*`;
+
+            // 4. If we have a comment, update it, otherwise create a new one
+            if (botComment) {
+              github.rest.issues.updateComment({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                comment_id: botComment.id,
+                body: output
+              })
+            } else {
+              github.rest.issues.createComment({
+                issue_number: context.issue.number,
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                body: output
+              })
+            }

.gitignore

@@ -0,0 +1,4 @@
+.DS_Store
+._.DS_Store
+**/.DS_Store
+**/._.DS_Store

README.md

@@ -5,6 +5,7 @@ This repository contains a collection of GitHub Actions workflow templates that
 ## Workflows
 
 - [Terraform Plan & Apply (AWS)](./docs/terraform-plan-and-apply-aws.md)
+- [Terraform Plan Only (AWS)](./docs/terraform-plan.md)
 - [Terraform Module Validation](./docs/terraform-module-validation.md)
 - [Terraform Module Release](./docs/terraform-module-release.md)
 

docs/terraform-plan-aws.md

@@ -0,0 +1,59 @@
+# Terraform Workflow for AWS Infrastructure
+
+This GitHub Actions workflow template ([terraform-plan-aws.yml](../.github/workflows/terraform-plan-aws.yml)) can be used with Terraform repositories to automate the testing and planning of AWS infrastructure. The workflow performs various steps such as authentication with AWS, Terraform formatting, initialization, validatio and planning. It also adds the Terraform plan output as a comment to the associated pull request and triggers an apply action for pushes to the main branch.
+
+## Workflow Steps
+
+1. **Setup Terraform:** Terraform is fetched at the specified version (overridable via inputs).
+2. **Terraform Format:** This step runs the terraform fmt command to check that all Terraform files are formatted correctly.
+3. **Terraform Lint:** This step runs terraform lint to check for deprecated syntax, unused declarations, invalid types, and enforcing best practices.
+4. **AWS Authentication:** The workflow uses Web Identity Federation to authenticate with AWS. The required AWS Role ARN must be provided as an input for successful authentication.
+   * A Web Identity Token File is also generated and stored in `/tmp/web_identity_token_file`, which can be referenced in Terraform Provider configuration blocks if required.
+5. **Terraform Init:** The Terraform backend is initialised and any necessary provider plugins are downloaded. The required inputs for AWS S3 bucket name and DynamoDB table name must be provided for storing the Terraform state.
+6. **Terraform Validate:** The workflow validates the Terraform configuration files using the terraform validate command to check for syntax errors and other issues.
+7. **Terraform Plan:** A Terraform plan is generated with a specified values file (overridable via inputs) using the terraform plan command.
+8. **Get Cost Estimate:** The infracost utility is run to get a cost estimate on the Terraform Plan output. A comment will be added to the pull request with the cost estimate.
+9. **Add PR Comment:** If the workflow is triggered via a Pull Request, a comment will be added to the ticket containing the results of the previous steps.
+
+## Inputs
+
+| Input | Required? | Default Value | Description |
+|-------|-------------|-----------|---------------|
+| aws-role-arn | Yes | | The ARN of the AWS role to assume for authentication |
+| aws-s3-bucket-name | Yes | | The name of the AWS S3 bucket to store the Terraform state |
+| aws-dynamodb-table-name | Yes | | The name of the AWS DynamoDB table to use for locking |
+| aws-region | No | eu-west-2 | The AWS region to deploy the infrastructure to |
+| terraform-log-level | No | INFO | The log level of Terraform |
+| terraform-state-key | No | ${{ github.event.repository.name }}.tfstate | The name of the Terraform state file to store in S3 |
+| terraform-values-file | No | values/production.tfvars | The path to the values file to use |
+| terraform-version | No | 1.5.2 | The version of Terraform to use |
+| working-directory | No | . | Which working directory to navigate to |
+
+## Usage
+
+Create a new workflow file in your Terraform repository (e.g. `.github/workflows/terraform.yml`) with the below contents:
+```yml
+name: Terraform Plan Generic Modules
+on:
+  push:
+    branches:
+    - main
+  pull_request:
+    branches:
+    - main
+
+jobs:
+  terraform:
+    uses: appvia/appvia-cicd-workflows/.github/workflows/terraform-plan-aws.yml@main
+    name: Terraform Run
+    secrets:
+        infracost-api-key: ${{ secrets.ORG_INFRACOST_API_KEY }}
+    with:
+      aws-account-id: 536471746696
+      enable-infracost: true
+      terraform-version: 1.5.7
+```
+
+The `aws-role-name` inputs are optional and will default to the repository name (with the respective `-ro` or `-rw` suffixes) if not provided.
+
+**Note:** This template may change over time, so it is recommended that you point to a tagged version rather than the main branch.