podman image trust set|show [options] registry[/repository]
Manages which registries you trust as a source of container images based on its location. (This option is not available with the remote Podman client)
The location is determined by the transport and the registry host of the image. Using this container image
docker://docker.io/library/busybox as an example,
docker is the transport and
docker.io is the registry host.
Trust is defined in /etc/containers/policy.json and is enforced when a user attempts to pull a remote image from a registry. The trust policy in policy.json describes a registry scope (registry and/or repository) for the trust. This trust can use public keys for signed images.
The scope of the trust is evaluated from most specific to the least specific. In other words, a policy may be defined for an entire registry. Or it could be defined for a particular repository in that registry. Or it could be defined down to a specific signed image inside of the registry.
For example, the following list includes valid scope values that could be used in policy.json from most specific to the least specific:
docker.io/library/busybox:notlatest docker.io/library/busybox docker.io/library docker.io
If no configuration is found for any of these scopes, the default value (specified by using "default" instead of REGISTRY[/REPOSITORY]) is used.
Trust type provides a way to:
Allowlist ("accept") or Denylist ("reject") registries or Require signature (“signedBy”).
Trust may be updated using the command podman image trust set for an existing trust scope.
Print usage statement.
A path to an exported public key on the local system. Key paths
will be referenced in policy.json. Any path to a file may be used but locating the file in /etc/pki/containers is recommended. Options may be used multiple times to
require an image be signed by multiple keys. The --pubkeysfile option is required for the signedBy type.
The trust type for this policy entry.
signedBy (default): Require signatures with corresponding list of
accept: do not require any signatures for this
reject: do not accept images for this registry scope
Output trust policy file as raw JSON
Output trust as JSON for machine parsing
Accept all unsigned images from a registry
sudo podman image trust set --type accept docker.io
Modify default trust policy
sudo podman image trust set -t reject default
Display system trust policy
sudo podman image trust show
Display trust policy file
sudo podman image trust show --raw
Display trust as JSON
sudo podman image trust show --json
January 2019, updated by Tom Sweeney (tsweeney at redhat dot com) December 2018, originally compiled by Qi Wang (qiwan at redhat dot com)
The man page docker-image-trust(1) is an alias of podman-image-trust(1).