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How to Use Sealos as a Private Container Repository

Working Principle​

Every node runs an image-cri-shim daemon. When Kubelet needs to pull an image, it initiates a gRPC interaction command to image-cri-shim. This process will search for the image name in the private repository. If it exists locally, it will pull from there, otherwise, it will pull from the remote.

Execute the following command to verify the status of the image-cri-shim daemon:

$ systemctl status image-cri-shim.service

Where the Private Repository Runs​

The private repository of Sealos runs by default on the first node of the cluster. The first node is the first node address entered when creating the cluster. Use the command below to check the status of the daemon:

$ systemctl status registry.service

Note: The repository data is saved in the /var/lib/sealos/data/default/rootfs/registry/ directory.

Login to the Private Container Image Repository​

Sealos private repository runs on HTTP using the --net host parameter. It should be locally configured with insecure-registries, and then connected using the IP address of the first node. The Docker client configuration is referenced as follows:

# cat /etc/docker/daemon.json 
{
  "insecure-registries": ["192.168.1.10:5000"],
}

Use the sealos login command for login. The default username and password are admin:passw0rd.

sealos login -u admin -p passw0rd 192.168.1.10:5000

You can also use the docker login command.

docker login -u admin -p passw0rd 192.168.1.10:5000

Pushing and Pulling Images​

Example of pushing an image:

$ sealos tag quay.io/skopeo/stable 192.168.72.50:5000/skopeo/stable
$ sealos push 192.168.72.50:5000/skopeo/stable
Using default tag: latest
The push refers to repository [192.168.72.50:5000/skopeo/stable]
a98b3d943f46: Pushed 
b48290351261: Pushed 
f39ec3c22bd5: Pushed 
e5a31cf70f11: Pushed 
b9394289d761: Pushed 
c550c8e0f355: Pushed 
latest: digest: sha256:238efd85942755fbd28d4d23d1f8dedd99e9eec20777e946f132633b826a9295 size: 1570

Example of pulling an image:

sealos pull 192.168.72.50:5000/skopeo/stable

Or use the docker pull command:

docker pull 192.168.72.50:5000/skopeo/stable