How could I list the images pushed to microk8s built-in registry

Question

I installed microk8s and I enabled registry addon I am able to push docker images to this registry and I am able to use this images in deployments.

But I'm trying to list images that was already pushed to this registry. How can I do that? Is there an API for that?

Alesandrini

Answer 1

I found that it's possible to list the registry images via HTTP GET in this address: http://<host_ip>:32000/v2/_catalog

It'll return the images in a json response

Alesandrini

Answer 2

Use command microk8s ctr images list. To know more use --help

microk8s ctr images --help
NAME:
   ctr images - manage images

USAGE:
   ctr images command [command options] [arguments...]

COMMANDS:
     check       check that an image has all content available locally
     export      export an image
     import      import images
     list, ls    list images known to containerd
     pull        pull an image from a remote
     push        push an image to a remote
     remove, rm  remove one or more images by reference
     label       set and clear labels for an image

OPTIONS:
   --help, -h  show help

Disagreement

I get the following response when I run this command: "Cannot use two forms of the same flag: n namespace" – Alesandrini

That returned a lot of information, but I cannot identify the images that were displayed. It returned their sha256 digest wich is not useful – Alesandrini

I am looking for the image's name and its tags – Alesandrini

I am getting only the cached images with this command. I know for a fact that there are other images on the registry that I cannot see here. Only after Kubernetes starts a pod with on of the images in the registry, that image appears in the list with this command. – Broccoli

Please keep in mind that the Docker REGISTRY and the images hosted in CONTAINERD are distinct things. – Francie

Answer 3

Following REST APIs will do the job:

1. Listing repositories:

http://host:32000/v2/_catalog?n=10

Last parameter n is the size of records to be returned. One can skip passing it but if you expect a long list then it's better to use pagination.

2. Listing the images in the repository

http://host:32000/v2/repositoryName/tags/list?n=10

Note: Replace host and repositoryName accordingly.

For complete reference visit: https://docs.docker.com/registry/spec/api/#listing-repositories

Sayers

Answer 4

Try this:

microk8s ctr images ls

Desdamonna

That returned a lot of information, but I cannot identify the images that were displayed. It returned their sha256 digest wich is not useful – Alesandrini

Answer 5

microk8s.ctr images ls

Run this to get your images. This is if you had installed microk8s as a snap. I'm using it on Ubuntu Core.

Kathikathiawar