Run a Custom Image

Boot a sandbox from your own OCI image, including private images that need registry credentials.

A Tektona sandbox runs whatever OCI image you point it at. Public images work with no setup. Private images need a registry credential stored on your organization so Tektona can pull them.

This guide assumes your image is already built and pushed to a registry. Building and pushing the image is out of scope.

Prerequisites

  • The tektona CLI installed and configured (tektona login), with an org/project context set (tektona ctx show).
  • An image already published to a container registry.

Run a public image

For an image in a public repository, reference it directly:

tektona sandbox create --image ghcr.io/acme/my-app:1.4.0

Image references must be deterministic: use a non-latest tag, a @sha256:… digest, or both. Tektona rejects a bare image or a bare :latest. See Manage Sandboxes → Choosing an image for the full rules and more examples.

Run a private image

Private images need a registry credential. You configure one per organization, and Tektona applies it automatically whenever a sandbox in that org references a matching image. You never pass it to sandbox create.

Work out your endpoint and namespace

Tektona builds the full image path as endpoint/namespace/image:tag. Pick the endpoint and namespace that match how you reference the image:

RegistryendpointnamespaceFull image path
GitLab CRregistry.gitlab.commygroup/myreporegistry.gitlab.com/mygroup/myrepo/image:tag
Docker Hubdocker.iomyuserdocker.io/myuser/image:tag
GitHub CRghcr.iomy-orgghcr.io/my-org/image:tag
Google ARus-docker.pkg.devproject/repous-docker.pkg.dev/project/repo/...
AWS ECR123456.dkr.ecr.us-east-1.amazonaws.com(empty)123456.dkr.ecr.../image:tag

Choose an auth type

All private registries require authentication. Pick the one your registry uses:

  • Personal access token (default) for GitHub and GitLab. Provide a username and the token.
  • Basic for username and password registries.
  • Bearer token for token-only registries.

Create the registry credential

Registries are managed in your project settings. Add a registry with the endpoint, namespace, and auth details from the previous steps.

Credentials are write-only. Tektona stores them encrypted and never shows them again. To rotate them, edit the registry and enter the new secret.

To automate this, use the registry endpoints in the API reference.

Create the sandbox

Reference the private image exactly as the registry's endpoint/namespace describes it:

tektona sandbox create --image ghcr.io/my-org/my-app:1.4.0 --ssh

If the image won't pull

A sandbox that errors right after creation usually has a registry credential that does not match the image reference:

  • The endpoint and namespace on the registry must match the image you passed to --image. ghcr.io/my-org/app needs endpoint ghcr.io and namespace my-org.
  • The auth type must match what the registry expects (token vs. username/password).
  • The token or password must still be valid and have read/pull scope for that repository.

Re-check the registry on the Registries page, fix the mismatch, and create a new sandbox.

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