Deploy artifacts to hosts

Multi-environment and multi-region deployment

Deploy across regions

To deploy to hosts in different regions (for example, the US and Japan) in a single pipeline, create a separate host group for each region. Add a VM Deploy job for each host group in the pipeline.

Orchestrate multiple microservices

To deploy multiple microservices to multiple hosts, you can use a single pipeline with separate build and deployment jobs for each service, or create individual pipelines per service for independent maintenance. You do not need a separate pipeline for each host — configure parallel deployment within host groups.

Select a deployment environment at runtime

Flow does not support dynamically selecting a deployment environment during a pipeline run. To control which environments to deploy to:

1. Create a separate host group for each environment (for example, staging and production).

2. Add a VM Deploy job for each host group in the pipeline.

3. Insert a Manual Confirmation node between deployment jobs to control the execution flow.

Choose the correct deployment component

When deploying to Alibaba Cloud ECS instances, use the VM Deploy component instead of the ECS Application component. The VM Deploy component connects to hosts through the Runner agent and correctly associates with your host instances.

Deployment script usage

The Deployment Script field is optional. If you leave it empty, Flow only downloads the artifact to the host without performing any deployment actions. No error is reported. Write the extraction, configuration, and startup logic in the deployment script to complete the deployment.

The inline deployment script has a character length limit. If your script exceeds the limit, upload the shell script file to a Git repository or the target host, and call it in the Deployment Script field. For example:

sh /home/admin/deploy.sh

Deploy multiple services independently on a single host

If you deploy multiple services to the same host and want to release them independently, create a separate host group for each service. The host groups can contain the same host. Configure a separate deployment job for each host group in the pipeline, and specify different download paths and startup scripts to isolate each deployment.

Run scripts in parallel

To run multiple scripts in parallel on a single host, add an additional VM Deploy component to the pipeline without selecting Download Artifacts During Deployment. Write your script commands directly in this component. The scripts in different VM Deploy components run in parallel with the main deployment.

Deployment mechanism and artifact transfer

Full artifact download

Each host deployment downloads the complete artifact package. Incremental updates are not supported.

Build stage vs. deployment stage

The "install" step in the build configuration installs dependencies such as JDK and Maven on the Flow build cluster, not on your host. The "upload artifact" step packages and uploads files to the artifact repository. The artifact is downloaded to your host only during the deployment stage.

Deploy static resources to a host

To deploy HTML or other static files to a host:

1. In the build stage, package the source files into an artifact.

2. In the deployment script, extract the files to the target directory:

   mkdir -p /home/admin/www/html
   tar zxvf /home/admin/app/package.tgz -C /home/admin/www/html/

Deploy artifacts to a custom directory

To deploy a JAR file or other artifact to a custom directory such as /app/jar/zh:

mkdir -p /app/jar/zh
tar zxvf /home/admin/app/package.tgz -C /app/jar/zh/
cd /app/jar/zh && sh start.sh

You can also place the startup script on the target host in advance.

Deploy with Docker Compose

Flow supports deploying applications with Docker Compose. Execute docker-compose commands in the Deployment Script.

Prerequisites

Docker and Docker Compose must be installed on the target host before deployment.

Synchronize the docker-compose.yml file

The pipeline does not automatically transfer the docker-compose.yml file from the code repository to the target host. Use one of the following methods to make the file available on the target host:

• Package the docker-compose.yml file into the build artifact during the build stage. The file is downloaded to the host with the artifact during deployment.

• Transfer the file in the deployment script using scp, wget, or git clone.

Example deployment script:

cd /home/admin/app
tar zxvf package.tgz
docker-compose up -d

Deploy Python or other code-based projects

For Python or similar projects, upload the code to the artifact repository during the build stage, then download and extract it during deployment. Alternatively, pull the code from Git in the deployment script.

View deployment details

After configuring the deployment job, run the pipeline. During deployment, click deployment details to view the status. On the pipeline run details page, find the VM Deploy job and click deployment details to open the details page.

Roll back a deployment

In the pipeline's Deployment History, find the deployment to roll back and click Roll Back.

A rollback re-executes the deployment using the historical artifact and deployment script. It is equivalent to running a new deployment with a previous version — not a simple state revert. If no historical artifact is available, rollback is not possible.

Troubleshoot deployment failures

Application not running after deployment succeeds

If the pipeline shows a successful deployment but the application is not running on the host, the most likely cause is a missing startup command in the deployment script. Host deployment only transfers the artifact and runs the deployment script. It does not automatically start applications. Ensure your deployment script includes commands to extract the artifact and start the application process. For example:

tar zxvf /home/admin/app/package.tgz -C /home/admin/application/
sh /home/admin/application/deploy.sh restart

Manage SLB traffic during deployment

To remove and restore Server Load Balancer (SLB) traffic during deployment, add traffic management commands to the deployment script. Best practices:

1. Create a host group that contains a single host.

2. Add the following steps in sequence within the deployment script: remove the host from the SLB, deploy the application, verify the deployment, and restore the host to the SLB.

3. Running all steps on the same host group prevents inconsistencies that occur when traffic removal and restoration target different hosts.