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An application can run a prebuilt Docker image instead of building from Git: Sevalla pulls the image from its registry on every deployment and runs it as the application’s processes, with no build. Public images need nothing else; private images need a registry credential, which you add once under Tools > Registry credentials and reuse across applications.

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Before you begin

  • The image is built for linux/amd64.
  • The image listens on the port in the PORT environment variable (8080 by default) and starts its server with its ENTRYPOINT or CMD. See Make the image run on Sevalla.
  • For a private image on Docker Hub, GitHub Container Registry or GitLab Container Registry, add a registry credential first.
  • The company has a valid payment method.

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Create an application from an image

1

Open the create form

In the sidebar, click Applications, then click Create > Application.
2

Choose the image

Under Source, click Docker image. In Docker image, enter the image reference, for example ghcr.io/acme/storefront:3.12.0.
3

Choose the credential

For a private image, choose its Registry credential. For a public image, leave None (public image).
4

Fill in the rest

Enter the Name, choose the Project if there is one, the Data center and the Size, as for any new application.
5

Create it

Click Create application.
The application opens with the status Not deployed yet. Click Deploy now, then Deploy: the deployment skips the build and goes straight to the rollout. When its status is Deployed, the application is Running.
The Create an application form with the Docker image source, an image reference, the Registry credential set to None (public image), and the SummaryThe Create an application form with the Docker image source, an image reference, the Registry credential set to None (public image), and the Summary
Docker image takes any image reference: a name (nginx), a name and tag (nginx:1.27), or a digest (nginx@sha256:...). Without a registry host, the image comes from Docker Hub. Without a tag or digest, Sevalla pulls latest. Use a tag or a digest, not both in one reference. The Summary shows no build cost: images aren’t built.

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Differences from a Git source

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Deploy a new image version

1

Open the deploy sheet

On the application’s Deployments tab, click Deploy now.
2

Set the version

Enter the Tag (for example 3.13.0). To pin an exact image instead, clear Tag and enter the Digest. Resolved image shows the image the deployment pulls.
3

Deploy

Click Deploy.
The deployment shows the image it pulled under Image in its Details card. The tag or digest you deploy applies to that deployment only. The application’s source keeps its image, and the deploy hook keeps deploying it. To change the image for good, update the source.

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Change the image or the credential

On the application’s Settings tab, in the Source section, click Update source. Enter the new Docker image or choose another Registry credential, then click Update source, and deploy. The same sheet switches the application to a Git repository, or a Git application to an image. Switching to an image turns off automatic deployments.

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Add a registry credential

A registry credential is a username and token that Sevalla uses to pull private images. It belongs to the company, so every application in it can use it, as a Docker image source or to pull private base images in a Dockerfile build.
1

Open registry credentials

In the sidebar, under Tools, click Registry credentials, then click Create registry credential.
2

Name it

Enter a Name you’ll recognize when you pick it, for example GitHub packages.
3

Choose the registry

Choose the Registry: Docker Hub, GitHub Container Registry or GitLab Container Registry.
4

Enter the account

Enter the Username of the registry account and, in Secret, a personal access token (or password) that can read the images.
5

Save

Click Create registry credential.
The credential appears in the list with its Registry and Created date, and in the Registry credential list of the create form and the Update source sheet.
The Create registry credential sheet with the Name, Registry, Username and Secret fieldsThe Create registry credential sheet with the Name, Registry, Username and Secret fields
You can’t update a credential in the dashboard. To change a token, create a new credential, switch the applications that use the old one, then delete it. The API can update a credential in place.

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Delete a registry credential

Sevalla doesn’t check whether a credential is in use. Applications that use a deleted credential can’t pull private images until you choose another credential in their source or build strategy, so their next deployment fails. You can’t undo this.
1

Open the credential's menu

Under Tools > Registry credentials, click ⋯ on the credential’s row, then Delete.
2

Confirm

Type the credential’s name, then click Delete credential.
The credential disappears from the list.

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Troubleshoot image deployments

Before the rollout, Sevalla checks that it can read the image. The build log shows:

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API and CLI

In the API and CLI, registry is dockerHub, github or gitlab.