Docker image deployment
Host Docker containers
Run a container image you already build and distribute. Polyer manages the service deployment while you define the image version, runtime configuration and data requirements.
Configuration checklist
- Image and version: verify the registry path and tag or digest you intend to run. Read upstream upgrade notes before changing versions.
- Registry credentials: configure credentials for private images and verify they grant access to the intended registry.
- Container networking: configure the listening port and public endpoint only for services that should receive external traffic.
- Health checks and startup: review the check path, timeout and any application initialization that must finish before traffic is accepted.
- Persistent data: map required data directories to volumes and confirm which data requires an independent backup.
From configuration to deployment
Choose the image
Open your workspace, select a project and environment, then enter the intended Docker image reference.
Configure image access
For a private image, select or configure registry credentials. Confirm the image version and application runtime requirements.
Review the runtime
Configure variables, ports, resource settings, health checks and volumes. Keep database connections private when external access is unnecessary.
Deploy and validate
Submit the configuration, inspect deployment and runtime logs, and test the endpoint. Verify that data remains available after a service restart.
Keep the service running
- Review image updates deliberately. Check release notes, migrations and persistence behavior before deploying a different version.
- A health check observes the configured endpoint; test the application's important workflows and dependency connections separately.
- Keep registry credentials valid and maintain a recovery plan for persistent data. A mounted volume does not replace a tested backup.
Questions before deployment
Can I use privileged containers or mount files from the host?
Services do not receive host access. If an application requires privileged mode, host devices or a Docker socket, resolve that requirement before choosing this deployment path. Include static files in the image and use a persistent volume for writable application data. Local bind mounts from a Compose file do not transfer your existing files to Polyer.
What should I check if the image cannot be pulled?
Read the deployment error before changing application settings. Confirm the registry hostname, repository name and tag or digest exist, then check that the selected credentials can pull that repository. Image access fails before the application starts, so changing its HTTP port or health-check path will not fix an authentication or missing-image error.
Should I use a Docker image or GitHub source deployment?
Use an image when your build already runs elsewhere or the application is distributed as a container. Use GitHub deployment when you want Polyer to build from your repository configuration.
Will files inside the container survive redeployment?
Do not rely on the writable container filesystem for durable application data. Configure a persistent volume for required data paths and verify the application's storage behavior.
Why is a running container not reachable?
Check the application's bind address and listening port, endpoint configuration and health-check logs. Also verify required variables and connections to dependent services.
Configure in your workspace
Signing in opens your workspace. Resources are created only after you submit the deployment configuration.