# K3s

### Import image into containerd

#### Offline

On a host where one can pull the image:

```
podman save -o <image_file_name>.tar <image_name>:<image_version>
gzip <image_file_name>.tar
```

Copy the file to target host(s) and then run:

```
zcat <image_file_name>.tar.gz | /usr/local/bin/k3s ctr images import -
```

#### Online

```
crictl pull <image_name_or_url>:<image_version>
```

If one needs to supply credentials for the registry, use:

```
   --auth AUTH_STRING                         Use AUTH_STRING for accessing the registry. AUTH_STRING is a base64
                                              encoded 'USERNAME[:PASSWORD]' [$CRICTL_AUTH]
   --creds USERNAME[:PASSWORD]                Use USERNAME[:PASSWORD] for accessing the registry [$CRICTL_CREDS]
   --username USERNAME, -u USERNAME           Use USERNAME for accessing the registry. The password will be
                                              requested on the command line
```

`-u` is most secure, as the password is not supplied on the command line.

### Access shell of container with root rights (uid 0)

Get container ID in the running pod:

```
kubectl -n hydra get pod <pod_name> -o jsonpath="{.status.containerStatuses[].containerID}" | sed 's,.*//,,'; echo ''
k3s ctr task exec -t --exec-id <random_name> --user root <container_id> bash
```