services: test-compose-predeploy: image: busybox:1.37.0-uclibc command: ["sleep", "600"] environment: SERVICE_VAR: from-service volumes: - test-compose-predeploy-data:/data x-pre_deploy: command: [sh, -c, echo hello-from-predeploy > /data/predeploy.txt] environment: HOOK_VAR: from-hook user: root timeout: 30s volumes: test-compose-predeploy-data: