feat: add preview environment workflow for PR deployments

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: baijum

.github/workflows/preview.yml

@@ -0,0 +1,133 @@
+name: Preview
+
+on:
+  pull_request:
+    types: [opened, synchronize, reopened, closed]
+
+jobs:
+  deploy-preview:
+    if: github.event.action != 'closed'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Deploy preview environment
+        uses: appleboy/ssh-action@v1
+        with:
+          host: ${{ secrets.SERVER_HOST }}
+          username: ${{ secrets.SERVER_USER }}
+          key: ${{ secrets.SERVER_SSH_KEY }}
+          script: |
+            set -e
+            APP_NAME="${{ github.event.repository.name }}"
+            PR_NUMBER="${{ github.event.number }}"
+            PREVIEW_DOMAIN="pr-${PR_NUMBER}.preview.${{ secrets.PREVIEW_DOMAIN }}"
+            APP_DB=$(echo "${APP_NAME}" | tr '-' '_')_db
+            SCHEMA_NAME="pr_${PR_NUMBER}"
+
+            cd /opt/apps/${APP_NAME}
+
+            # Fetch and checkout the PR branch
+            git fetch origin pull/${PR_NUMBER}/head:pr-${PR_NUMBER} --force
+            git checkout pr-${PR_NUMBER}
+
+            # Create preview schema in the app's database
+            docker compose -f /opt/platform/docker-compose.yml exec -T postgres \
+              psql -U postgres -d ${APP_DB} -c "CREATE SCHEMA IF NOT EXISTS ${SCHEMA_NAME}"
+
+            # Read the app's .env and generate a preview-specific version
+            # with DATABASE_URL pointing to the PR schema
+            if [ ! -f deploy/.env ]; then
+              echo "ERROR: deploy/.env not found. Create it from deploy/env.template first."
+              exit 1
+            fi
+
+            # Generate preview .env with schema-aware DATABASE_URL
+            sed "s|^DATABASE_URL=.*|DATABASE_URL=postgresql://postgres:$(grep POSTGRES_PASSWORD /opt/platform/.env | cut -d= -f2)@postgres:5432/${APP_DB}?options=-csearch_path%3D${SCHEMA_NAME}|" \
+              deploy/.env > deploy/.env.pr-${PR_NUMBER}
+
+            # Build and start preview containers
+            docker compose -p ${APP_NAME}-pr-${PR_NUMBER} -f deploy/docker-compose.yml \
+              --env-file deploy/.env.pr-${PR_NUMBER} up -d --build
+
+            # Run database migrations against the preview schema
+            docker compose -p ${APP_NAME}-pr-${PR_NUMBER} -f deploy/docker-compose.yml \
+              exec -T app alembic -c app/alembic.ini upgrade head
+
+            # Generate Caddyfile for preview domain
+            cat > /opt/platform/caddy-apps/${APP_NAME}-pr-${PR_NUMBER}.caddy <<CADDYEOF
+            ${PREVIEW_DOMAIN} {
+                reverse_proxy ${APP_NAME}-pr-${PR_NUMBER}-app-1:8000
+            }
+            CADDYEOF
+
+            # Reload Caddy to pick up new route
+            docker compose -f /opt/platform/docker-compose.yml exec -T caddy \
+              caddy reload --config /etc/caddy/Caddyfile
+
+            # Switch back to main so production deploys aren't affected
+            git checkout main
+
+      - name: Post preview URL
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const previewDomain = `pr-${{ github.event.number }}.preview.${{ secrets.PREVIEW_DOMAIN }}`;
+            const body = `Preview deployed: https://${previewDomain}\n\nHealth check: https://${previewDomain}/health`;
+            const { data: comments } = await github.rest.issues.listComments({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: context.issue.number,
+            });
+            const existing = comments.find(c => c.body.startsWith('Preview deployed:'));
+            if (existing) {
+              await github.rest.issues.updateComment({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                comment_id: existing.id,
+                body,
+              });
+            } else {
+              await github.rest.issues.createComment({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: context.issue.number,
+                body,
+              });
+            }
+
+  cleanup-preview:
+    if: github.event.action == 'closed'
+    runs-on: ubuntu-latest
+    steps:
+      - name: Clean up preview environment
+        uses: appleboy/ssh-action@v1
+        with:
+          host: ${{ secrets.SERVER_HOST }}
+          username: ${{ secrets.SERVER_USER }}
+          key: ${{ secrets.SERVER_SSH_KEY }}
+          script: |
+            set -e
+            APP_NAME="${{ github.event.repository.name }}"
+            PR_NUMBER="${{ github.event.number }}"
+            APP_DB=$(echo "${APP_NAME}" | tr '-' '_')_db
+            SCHEMA_NAME="pr_${PR_NUMBER}"
+
+            # Stop and remove preview containers
+            cd /opt/apps/${APP_NAME}
+            docker compose -p ${APP_NAME}-pr-${PR_NUMBER} -f deploy/docker-compose.yml down --rmi local || true
+
+            # Drop the preview schema
+            docker compose -f /opt/platform/docker-compose.yml exec -T postgres \
+              psql -U postgres -d ${APP_DB} -c "DROP SCHEMA IF EXISTS ${SCHEMA_NAME} CASCADE"
+
+            # Remove preview Caddyfile
+            rm -f /opt/platform/caddy-apps/${APP_NAME}-pr-${PR_NUMBER}.caddy
+
+            # Reload Caddy
+            docker compose -f /opt/platform/docker-compose.yml exec -T caddy \
+              caddy reload --config /etc/caddy/Caddyfile
+
+            # Clean up preview .env and branch
+            rm -f deploy/.env.pr-${PR_NUMBER}
+            git branch -D pr-${PR_NUMBER} || true