title: Deploy a Docker image description: Run any image from Docker Hub, GitHub Container Registry or another registry, public or private.

Run a prebuilt image when your CI already builds one, or to run off-the-shelf software. Ployz pulls the image onto your servers and runs it, with nothing to build.

Add a service from an image

Before you deploy, find the port the image listens on, like 80 for nginx. Ployz sends traffic to the port in the service's PORT variable, 8080 unless you set it, so give it the image's port: on the domain, or as a PORT variable. If you miss it and the image declares the ports it listens on, the deploy warns and names them. See Domains.

1. Open your project and click Create, then Docker image.
2. Enter the image, such as nginx:1.27, and click Continue. For a private image, add its credentials next.
3. If it should be public, open the service's Settings → Networking, click Generate Domain, and enter the image's port in Port.
4. Click Deploy in the bottom bar.

Write the image the way docker pull takes it. Without a tag, Ployz uses latest.

Mixed servers. If your servers mix x86 and ARM, the image needs both a linux/amd64 and a linux/arm64 variant.

Change the image or its tag

1. Open the service and go to Settings → Source.
2. Click the pencil next to Container image, enter the new image and click Continue.
3. Deploy the change.

Ship a new version of your image

Ployz doesn't watch registries, so pushing a new image deploys nothing. Deploying the same tag again doesn't help either: a server that already has latest keeps its old copy.

Give each release its own tag, like 1.5.0 or the Git commit, and change Container image to it. Doing that from your CI after it pushes the image is CLI-only:

With more than one project, or to deploy to an environment other than the default, add --project and --env to both commands. See CLI and coding agents to make the token.

Use a private image

1. Open the service and go to Settings → Source.
2. Under Registry credentials, click Add credentials.
3. Fill in what the form asks for your registry, and save it.
4. Deploy the change.

Ployz stores the secret encrypted and never shows it again. The Registry credentials row shows the provider and registry, like Docker Hub · docker.io. To replace it, click the pencil. A new secret takes effect at once, not as a staged change, and Discard can't bring the old one back. Disconnect stops using credentials from your next deploy, and Restore undoes it until then.

An expired token fails the next pull. Use a long-lived token where your registry offers one. ECR Public tokens are short-lived, so replace the secret before each deploy.

Override the start command

A service runs the image's own command. To run something else, such as a worker from the same image:

1. Open the service and go to Settings → Deploy.
2. Click Start command and enter the command, like npm run worker.
3. Deploy the change.

The start command replaces the image's ENTRYPOINT and CMD, the same as on Railway. It runs directly, without a shell, so it works on images that have none:

• Quotes group words, and a backslash escapes the next character.
• Variables like $PORT stay as written. Ployz doesn't expand them.
• The command ends at the first ;, &, |, < or > outside quotes. In npm run migrate && npm start, only npm run migrate runs.

To use variables or chain commands, run a shell yourself, like sh -c 'npm run migrate && exec npm start --port "$PORT"'. Clear the field to go back to the image's own command.

Next: give your app its variables.