Add PR environments

.github/workflows/ci-{{app_name}}-pr-environment-checks.yml.jinja

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+name: CI {{ app_name }} PR Environment Checks
+on:
+  workflow_dispatch:
+    inputs:
+      pr_number:
+        required: true
+        type: string
+      commit_hash:
+        required: true
+        type: string
+  {% if app_has_dev_env_setup %}
+  pull_request:
+  {% else %}
+  # !! Once you've set up the dev environment and are ready to enable PR
+  # environments, run:
+  #
+  # nava-platform infra update --answers-only --data app_has_dev_env_setup=true .
+  #
+  # to enable these lines. They are here as comments for context.
+  #
+  # pull_request:
+  {% endif %}
+
+jobs:
+  update:
+    name: " " # GitHub UI is noisy when calling reusable workflows, so use whitespace for name to reduce noise
+    uses: ./.github/workflows/pr-environment-checks.yml
+    if: github.event_name == 'workflow_dispatch' || github.event.pull_request.state == 'open'
+    with:
+      app_name: "{{ app_name }}"
+      environment: "dev"
+      pr_number: ${{'{{'}} inputs.pr_number || github.event.number {{'}}'}}
+      commit_hash: ${{'{{'}} inputs.commit_hash || github.event.pull_request.head.sha {{'}}'}}

.github/workflows/ci-{{app_name}}-pr-environment-destroy.yml.jinja

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+name: CI {{ app_name }} PR Environment Destroy
+on:
+  workflow_dispatch:
+    inputs:
+      pr_number:
+        required: true
+        type: string
+  {% if app_has_dev_env_setup %}
+  pull_request_target:
+    types: [closed]
+  {% else %}
+  # !! Once you've set up the dev environment and are ready to enable PR
+  # environments, run:
+  #
+  # nava-platform infra update --answers-only --data app_has_dev_env_setup=true .
+  #
+  # to enable these lines. They are here as comments for context.
+  #
+  # pull_request_target:
+  #   types: [closed]
+  {% endif %}
+
+jobs:
+  destroy:
+    name: " " # GitHub UI is noisy when calling reusable workflows, so use whitespace for name to reduce noise
+    uses: ./.github/workflows/pr-environment-destroy.yml
+    with:
+      app_name: "{{ app_name }}"
+      environment: "dev"
+      pr_number: ${{'{{'}} inputs.pr_number || github.event.number {{'}}'}}

.github/workflows/pr-environment-checks.yml

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+name: PR Environment Update
+run-name: Update PR Environment ${{ inputs.pr_number }}
+on:
+  workflow_call:
+    inputs:
+      app_name:
+        required: true
+        type: string
+      environment:
+        required: true
+        type: string
+      pr_number:
+        required: true
+        type: string
+      commit_hash:
+        required: true
+        type: string
+
+concurrency: pr-environment-${{ inputs.app_name }}-${{ inputs.pr_number }}
+
+jobs:
+  build-and-publish:
+    name: " " # GitHub UI is noisy when calling reusable workflows, so use whitespace for name to reduce noise
+    uses: ./.github/workflows/build-and-publish.yml
+    with:
+      app_name: ${{ inputs.app_name }}
+      ref: ${{ inputs.commit_hash }}
+
+  update:
+    name: Update environment
+    needs: [build-and-publish]
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: read
+      id-token: write
+      pull-requests: write # Needed to comment on PR
+      repository-projects: read # Workaround for GitHub CLI bug https://github.com/cli/cli/issues/6274
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Terraform
+        uses: ./.github/actions/setup-terraform
+
+      - name: Configure Azure credentials
+        uses: ./.github/actions/configure-azure-credentials
+        with:
+          app_name: ${{ inputs.app_name }}
+          environment: ${{ inputs.environment }}
+
+      - name: Update environment
+        run: ./bin/update-pr-environment "${{ inputs.app_name }}" "${{ inputs.environment }}" "${{ inputs.pr_number }}" "${{ inputs.commit_hash }}"
+        env:
+          GH_TOKEN: ${{ github.token }}

.github/workflows/pr-environment-destroy.yml

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+name: PR Environment Destroy
+run-name: Destroy PR Environment ${{ inputs.pr_number }}
+on:
+  workflow_call:
+    inputs:
+      app_name:
+        required: true
+        type: string
+      environment:
+        required: true
+        type: string
+      pr_number:
+        required: true
+        type: string
+
+concurrency: pr-environment-${{ inputs.app_name }}-${{ inputs.pr_number }}
+
+jobs:
+  destroy:
+    name: Destroy environment
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: read
+      id-token: write
+      pull-requests: write # Needed to comment on PR
+      repository-projects: read # Workaround for GitHub CLI bug https://github.com/cli/cli/issues/6274
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Terraform
+        uses: ./.github/actions/setup-terraform
+
+      - name: Configure Azure credentials
+        uses: ./.github/actions/configure-azure-credentials
+        with:
+          app_name: ${{ inputs.app_name }}
+          environment: ${{ inputs.environment }}
+
+      - name: Destroy environment
+        run: ./bin/destroy-pr-environment "${{ inputs.app_name }}" "${{ inputs.environment }}" "${{ inputs.pr_number }}"
+        env:
+          GH_TOKEN: ${{ github.token }}

.github/workflows/scan-orphaned-environments.yml

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+# This workflow scans for temporary environments that were not properly cleaned up
+# This can happen if the PR environment destroy workflow failed or didn't run
+# or if the temporary environments created by the infra service tests were not cleaned up
+name: Scan orphaned environments
+
+on:
+  workflow_dispatch:
+  schedule:
+    # Run every day at 07:30 UTC (3:30am ET, 12:30am PT) after engineers are likely done with work
+    - cron: "30 7 * * *"
+
+jobs:
+  get-app-names:
+    name: Get app names
+    runs-on: ubuntu-latest
+
+    outputs:
+      app_names: ${{ steps.get-app-names.outputs.app_names }}
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Get app names
+        id: get-app-names
+        run: |
+          source bin/util.sh
+          app_names="$(get_app_names)"
+          # turn app_names into a json list using jq
+          app_names="$(echo "${app_names}" | jq -R -s -c 'split("\n")[:-1]')"
+          echo "App names retrieved: ${app_names}"
+          echo "app_names=${app_names}" >> "$GITHUB_OUTPUT"
+        shell: bash
+
+  scan:
+    name: Scan
+    runs-on: ubuntu-latest
+    needs: get-app-names
+
+    strategy:
+      fail-fast: false
+      matrix:
+        app_name: ${{ fromJson(needs.get-app-names.outputs.app_names) }}
+        scan_script: [orphaned-pr-environments, stale-test-environments]
+
+    permissions:
+      contents: read
+      id-token: write
+      pull-requests: read
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Terraform
+        uses: ./.github/actions/setup-terraform
+
+      - name: Configure Azure credentials
+        uses: ./.github/actions/configure-azure-credentials
+        with:
+          app_name: ${{ matrix.app_name }}
+          environment: dev
+
+      - name: List PR workspaces
+        run: |
+          ./bin/${{ matrix.scan_script }} ${{ matrix.app_name }}
+        env:
+          GH_TOKEN: ${{ github.token }}
+          TF_IN_AUTOMATION: "true"
+
+  # TODO(#50): Add a notify job that posts to Slack on failure. Until then,
+  # orphaned-environment alerts only show up in the Actions UI.

bin/destroy-pr-environment

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+#!/usr/bin/env bash
+# -----------------------------------------------------------------------------
+# Destroy the temporary environment that was created for the pull request.
+#
+# Positional parameters:
+#   app_name (required) – the name of subdirectory of /infra that holds the
+#     application's infrastructure code.
+#   environment - the name of the application environment (e.g. dev, staging, prod)
+#   pr_number - the pull request number in GitHub
+# -----------------------------------------------------------------------------
+set -euo pipefail
+
+app_name="$1"
+environment="$2"
+pr_number="$3"
+
+# Validate app_name
+if [ ! -d "infra/${app_name}/service" ]; then
+  echo "Error: App '${app_name}' not found in infra/"
+  exit 1
+fi
+
+workspace="p-${pr_number}"
+
+# Safety check: never allow deleting the default workspace
+if [ "$workspace" = "default" ] || [ -z "$workspace" ]; then
+  echo "Error: Refusing to delete default or empty workspace"
+  exit 1
+fi
+
+echo "::group::Initialize Terraform with backend for environment: ${environment}"
+terraform -chdir="infra/${app_name}/service" init -backend-config="${environment}.azurerm.tfbackend"
+echo "::endgroup::"
+
+echo "Check if Terraform workspace exists: ${workspace}"
+# List workspaces and check if our workspace exists
+# Note: workspace list shows current workspace with "* " prefix, others with "  " prefix
+if terraform -chdir="infra/${app_name}/service" workspace list | grep -qE "^[* ] +${workspace}$"; then
+  echo "Workspace ${workspace} exists, proceeding with destroy"
+else
+  echo "Workspace ${workspace} does not exist - nothing to destroy"
+  echo "This can happen if the workspace was already cleaned up or never created"
+  exit 0
+fi
+
+echo "Select Terraform workspace: ${workspace}"
+terraform -chdir="infra/${app_name}/service" workspace select "${workspace}"
+
+echo "::group::Destroy resources"
+# Retry terraform destroy to handle transient Azure API errors
+max_tf_attempts=3
+tf_attempt=0
+tf_success=false
+
+while [ $tf_attempt -lt $max_tf_attempts ] && [ "$tf_success" = "false" ]; do
+  tf_attempt=$((tf_attempt + 1))
+
+  if [ $tf_attempt -gt 1 ]; then
+    echo "Retry attempt ${tf_attempt}/${max_tf_attempts} after transient failure..."
+  fi
+
+  if terraform -chdir="infra/${app_name}/service" destroy -var="environment_name=${environment}" -input=false -auto-approve; then
+    tf_success=true
+    echo "Terraform destroy succeeded"
+  else
+    if [ $tf_attempt -lt $max_tf_attempts ]; then
+      echo "Terraform destroy failed, waiting 30s before retry..."
+      sleep 30
+    fi
+  fi
+done
+
+if [ "$tf_success" = "false" ]; then
+  echo "Error: Terraform destroy failed after ${max_tf_attempts} attempts"
+  exit 1
+fi
+echo "::endgroup::"
+
+echo "Select default workspace"
+terraform -chdir="infra/${app_name}/service" workspace select default
+
+echo "Delete workspace: ${workspace}"
+terraform -chdir="infra/${app_name}/service" workspace delete "${workspace}"
+
+pr_info=$(cat <<EOF
+<!-- ${app_name} - begin PR environment info -->
+## Preview environment for ${app_name}
+♻️ Environment destroyed ♻️
+<!-- ${app_name} - end PR environment info -->
+EOF
+)
+
+echo "Update PR description with PR environment info"
+echo "${pr_info}"
+
+# Use a retry loop to handle race conditions when multiple workflows update the PR body
+max_attempts=5
+attempt=0
+updated=false
+
+while [ $attempt -lt $max_attempts ] && [ "$updated" = "false" ]; do
+  attempt=$((attempt + 1))
+
+  # Read current PR body
+  pr_body="$(gh pr view "${pr_number}" --json body | jq --raw-output .body)"
+
+  # clean up older single-app section if present
+  if [[ $pr_body == *"<!-- begin PR environment info -->"*"<!-- end PR environment info -->"* ]]; then
+    pr_body="${pr_body//<!-- begin PR environment info -->*<!-- end PR environment info -->}"
+  fi
+
+  if [[ $pr_body == *"<!-- ${app_name} - begin PR environment info -->"*"<!-- ${app_name} - end PR environment info -->"* ]]; then
+    pr_body="${pr_body//<!-- ${app_name} - begin PR environment info -->*<!-- ${app_name} - end PR environment info -->/$pr_info}"
+  else
+    pr_body="${pr_body}"$'\n\n'"${pr_info}"
+  fi
+
+  # Try to update the PR body
+  if gh pr edit "${pr_number}" --body "${pr_body}"; then
+    updated=true
+    echo "Successfully updated PR description"
+  else
+    if [ $attempt -lt $max_attempts ]; then
+      echo "Failed to update PR description (attempt ${attempt}/${max_attempts}), retrying in 2s..."
+      sleep 2
+    fi
+  fi
+done
+
+if [ "$updated" = "false" ]; then
+  echo "Warning: Failed to update PR description after ${max_attempts} attempts"
+  # Don't fail the workflow just because we couldn't update the PR body
+  echo "Continuing despite PR update failure..."
+fi