Images

Pull an image: 

ctr image pull docker.io/library/nginx:latest

List images: 

ctr image ls -q

Tag an image: 

ctr image tag docker.io/library/nginx:latest caizhe.org/library/nginx:latest

Remove an image: 

ctr images rm caizhe.org/library/nginx:latest

Mount an image to a local directory: 

ctr image mount docker.io/library/nginx:latest /mnt

Unmount: 

ctr image unmount /mnt

Export: 

ctr image export nginx.tar.gz docker.io/library/nginx:latest

Import: 

ctr i import nginx.tar.gz

Fixing the ctr: content digest sha256:xxxxxx not found error: 

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Option 1:
    ctr image pull --platform amd64  docker.io/library/nginx:latest 
    ctr i export --platform amd64 nginx.tar.gz docker.io/library/nginx:latest
    ctr i import --platform amd64 nginx.tar.gz 
Option 2:
    ctr i pull --all-platforms docker.io/library/nginx:latest
    ctr i export --all-platforms nginx.tar.gz docker.io/library/nginx:latest
    ctr i import nginx.tar.gz

Containers

Create a container: 

ctr container create docker.io/library/nginx:latest nginx

List containers: 

ctr container ls

Remove a container: 

ctr container rm nginx

Start a container: 

ctr task start -d nginx

Create and start a container in one step: 

ctr run -d  --net-host nginx bash

Check container status: 

ctr task ls

Enter a container: 

ctr task exec -t --exec-id 0 nginx /bin/bash

Stop a container: 

ctr task kill nginx

Pause a container: 

ctr task pause nginx

Check container resource usage: 

ctr task metrics nginx

Namespaces

List namespaces: 

ctr ns ls

Create a namespace: 

ctr ns create test

Remove a namespace: 

ctr ns rm test

Tip: Docker’s namespace is moby ; Kubernetes’ namespace is k8s.io .