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If you already publish an image, you can run it directly. Symplax pulls it onto your server and runs it with the same zero-downtime swap, nginx routing and free HTTPS subdomain as an app built from GitHub. There is no build step, so the builder queue never holds it up.
Private registries are not supported yet. The image must be one anyone can pull.

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Deploy an image

1

Open the deploy sheet

Go to Apps and click Deploy App. Under Deployment source, pick Docker image.
2

Name the image

Type the image reference in Image. A bare name means Docker Hub, and no tag means :latest.
3

Set the port only if you need to

Leave Container port empty and Symplax reads the port from the image’s EXPOSE. Set it if your image declares no port, or more than one.
4

Name it, pick a server, add variables

Choose the Target server, optionally a domain, and add environment variables. Click Start Deployment.

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How the port is chosen

When you leave the port empty, Symplax inspects the pulled image:
  • One exposed TCP port: Symplax uses it and says so in the deploy log.
  • Several exposed ports: the deploy stops and asks you to set the container port.
  • No exposed port: the deploy stops and asks you to set the container port.
You can change the port later under Port in the app’s Settings tab, then redeploy.

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How the health check works

Symplax did not build your image, so it does not guess what a healthy response looks like. Unless you set a health check, it only checks that the container is running and accepting connections on its port before swapping it in. To check a real endpoint, set Health Check in Settings to a path and the status code it returns, for example /healthz and 200. Symplax then waits for that response before it switches traffic.

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Updating the image

Click Redeploy to pull the same reference again and swap to it. If your reference is a moving tag such as :latest or :v2, this picks up whatever the tag points to now. Settings that only make sense for a build, such as Root Directory, Dockerfile Path, Start Command and Build Command, are hidden for image apps. Auto-deploy on push does not apply, because there is no repository.

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What still applies

Everything after the build works the same as for any app:
One image runs as one container. Symplax does not run multi-container setups. If you have a docker-compose.yml with one app and its databases, see Monorepos.
Looking for a ready-made app such as n8n or Ghost? The marketplace installs them with their databases and secrets set up for you.