Add in rolling release to the deployment script

deploy/deploy.sh

@@ -14,22 +14,78 @@ RELEASES_DIR="/home/deploy/releases"
 DEPLOY_BIN="/home/deploy/production/zenbin"
 SERVICE_NAME="zenbin"
 BINARY_NAME="zenbin-${COMMIT_HASH}"
+PORTS=(3000 3001 3002)
 
 # Check if the binary exists
 if [ ! -f "${RELEASES_DIR}/${BINARY_NAME}" ]; then
   echo "Binary ${BINARY_NAME} not found in ${RELEASES_DIR}"
   exit 1
 fi
 
+# Keep a reference to the previous binary from the symlink
+if [ -L "${DEPLOY_BIN}" ]; then
+  PREVIOUS=$(readlink -f "${DEPLOY_DIR}/${SYMLINK_NAME}")
+  echo "Current binary is ${PREVIOUS}, saved for rollback."
+else
+  echo "No symbolic link found, no previous binary to backup."
+  PREVIOUS=""
+fi
+
+rollback_deployment() {
+  if [ -n "$PREVIOUS" ]; then
+    echo "Rolling back to previous binary: ${PREVIOUS}"
+    ln -sfn "${PREVIOUS}" "${DEPLOY_BIN}"
+  else
+    echo "No previous binary to roll back to."
+  fi
+
+  # Restart all services with the previous binary
+  for port in $PORTS; do
+    SERVICE="${SERVICE_NAME}@${port}.service"
+    echo "Restarting $SERVICE..."
+    sudo systemctl restart $SERVICE
+  done
+
+  echo "Rollback completed."
+}
+
 # Copy the binary to the deployment directory
 echo "Promoting ${BINARY_NAME} to ${DEPLOY_BIN}..."
 ln -sf "${RELEASES_DIR}/${BINARY_NAME}" "${DEPLOY_BIN}"
 
-for port in 3000 3001 3002; do
+WAIT_TIME=5
+restart_service() {
+  local port=$1
+  local SERVICE="${SERVICE_NAME}@${port}.service"
+  echo "Restarting ${SERVICE}..."
+
   # Restart the service
-  SERVICE="${SERVICE_NAME}@${port}.service"
-  echo "Restarting the ${SERVICE} service..."
-  sudo systemctl restart ${SERVICE}
+  if ! sudo systemctl restart "$SERVICE"; then
+    echo "Error: Failed to restart ${SERVICE}. Rolling back deployment."
+
+    # Call the rollback function
+    rollback_deployment
+    exit 1
+  fi
+
+  # Wait a few seconds to allow the service to fully start
+  echo "Waiting for ${SERVICE} to fully start..."
+  sleep $WAIT_TIME
+
+  # Check the status of the service
+  if ! systemctl is-active --quiet "${SERVICE}"; then
+    echo "Error: ${SERVICE} failed to start correctly. Rolling back deployment."
+
+    # Call the rollback function
+    rollback_deployment
+    exit 1
+  fi
+
+  echo "${SERVICE}.service restarted successfully."
+}
+
+for port in $PORTS; do
+  restart_service $port
 done
 
 echo "Deployment completed successfully."