feat(ci): create dedicated deploy workflow for Terraform

- Separate workflow for push events to dev only
- Apply job runs when plan detects changes
- Use has_changes output (true/false) instead of exitcode

Refs #3

.gitea/workflows/terraform-deploy.yml

@@ -0,0 +1,146 @@
+name: Terraform Deploy
+
+on:
+  push:
+    branches:
+      - dev
+    paths:
+      - 'terraform/**'
+      - '.gitea/workflows/terraform-*.yml'
+
+env:
+  TF_WORKING_DIR: terraform/prod
+  AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
+  AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
+  TF_VAR_proxmox_url: ${{ secrets.PROXMOX_URL }}
+  TF_VAR_proxmox_api_token: ${{ secrets.PROXMOX_API_TOKEN }}
+  TF_VAR_tailscale_auth_key: ${{ secrets.TAILSCALE_AUTH_KEY }}
+  GIT_TOKEN: ${{ secrets.GIT_TOKEN }}
+
+jobs:
+  validate:
+    name: Validate
+    runs-on: self-hosted
+    container:
+      image: gitea.arnodo.fr/damien/terraform-ci:latest
+    steps:
+      - name: Checkout
+        run: |
+          git clone --depth 1 --branch "${{ gitea.ref_name }}" https://${GIT_TOKEN}@gitea.arnodo.fr/${{ gitea.repository }}.git .
+
+      - name: Terraform Format Check
+        id: fmt
+        run: terraform fmt -check -recursive -diff
+        working-directory: ${{ env.TF_WORKING_DIR }}
+        continue-on-error: true
+
+      - name: TFLint
+        id: lint
+        run: tflint --recursive --format compact
+        working-directory: ${{ env.TF_WORKING_DIR }}
+        continue-on-error: true
+
+      - name: Terraform Init
+        id: init
+        run: terraform init -input=false
+        working-directory: ${{ env.TF_WORKING_DIR }}
+
+      - name: Terraform Validate
+        id: validate
+        run: terraform validate -no-color
+        working-directory: ${{ env.TF_WORKING_DIR }}
+
+      - name: Validation Summary
+        if: always()
+        run: |
+          echo "## Validation Results" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+          echo "| Check | Status |" >> $GITHUB_STEP_SUMMARY
+          echo "|-------|--------|" >> $GITHUB_STEP_SUMMARY
+          echo "| Format | ${{ steps.fmt.outcome == 'success' && '✅' || '❌' }} |" >> $GITHUB_STEP_SUMMARY
+          echo "| TFLint | ${{ steps.lint.outcome == 'success' && '✅' || '⚠️' }} |" >> $GITHUB_STEP_SUMMARY
+          echo "| Init | ${{ steps.init.outcome == 'success' && '✅' || '❌' }} |" >> $GITHUB_STEP_SUMMARY
+          echo "| Validate | ${{ steps.validate.outcome == 'success' && '✅' || '❌' }} |" >> $GITHUB_STEP_SUMMARY
+
+      - name: Check Validation Status
+        if: steps.fmt.outcome == 'failure' || steps.init.outcome == 'failure' || steps.validate.outcome == 'failure'
+        run: exit 1
+
+  plan:
+    name: Plan
+    runs-on: self-hosted
+    container:
+      image: gitea.arnodo.fr/damien/terraform-ci:latest
+    needs: validate
+    outputs:
+      has_changes: ${{ steps.plan.outputs.has_changes }}
+    steps:
+      - name: Checkout
+        run: |
+          git clone --depth 1 --branch "${{ gitea.ref_name }}" https://${GIT_TOKEN}@gitea.arnodo.fr/${{ gitea.repository }}.git .
+
+      - name: Terraform Init
+        run: terraform init -input=false
+        working-directory: ${{ env.TF_WORKING_DIR }}
+
+      - name: Terraform Plan
+        id: plan
+        run: |
+          set +e
+          terraform plan -input=false -no-color -detailed-exitcode -out=tfplan 2>&1 | tee plan_output.txt
+          EXITCODE=$?
+          
+          # Determine if there are changes
+          if [ $EXITCODE -eq 2 ]; then
+            echo "has_changes=true" >> $GITHUB_OUTPUT
+          else
+            echo "has_changes=false" >> $GITHUB_OUTPUT
+          fi
+          
+          # Exit 1 is error, 0 and 2 are OK
+          if [ $EXITCODE -eq 1 ]; then
+            exit 1
+          fi
+          exit 0
+        working-directory: ${{ env.TF_WORKING_DIR }}
+
+      - name: Plan Summary
+        if: always()
+        run: |
+          echo "## Terraform Plan" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+          echo "**Has changes:** \`${{ steps.plan.outputs.has_changes }}\`" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+          echo '```' >> $GITHUB_STEP_SUMMARY
+          cat plan_output.txt >> $GITHUB_STEP_SUMMARY
+          echo '```' >> $GITHUB_STEP_SUMMARY
+        working-directory: ${{ env.TF_WORKING_DIR }}
+
+  apply:
+    name: Apply
+    runs-on: self-hosted
+    container:
+      image: gitea.arnodo.fr/damien/terraform-ci:latest
+    needs: plan
+    if: needs.plan.outputs.has_changes == 'true'
+    steps:
+      - name: Checkout
+        run: |
+          git clone --depth 1 --branch "${{ gitea.ref_name }}" https://${GIT_TOKEN}@gitea.arnodo.fr/${{ gitea.repository }}.git .
+
+      - name: Terraform Init
+        run: terraform init -input=false
+        working-directory: ${{ env.TF_WORKING_DIR }}
+
+      - name: Terraform Apply
+        run: |
+          terraform plan -input=false -out=tfplan
+          terraform apply -input=false -auto-approve tfplan
+        working-directory: ${{ env.TF_WORKING_DIR }}
+
+      - name: Apply Summary
+        if: always()
+        run: |
+          echo "## ✅ Terraform Apply Complete" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+          echo "Infrastructure has been updated successfully." >> $GITHUB_STEP_SUMMARY