Containerd: "ctr containers ls" get nothing

[czm4514]

When i use the command "ctr containers ls" to get the running containers,i can get nothing.

[root@XXX ~]# ctr containers ls
CONTAINER    IMAGE    RUNTIME   

however ,When i use the command "systemctl status containers" to get some info about containerd. i found that there are lots of containers .such as

[root@XXX~]# systemctl status containerd
● containerd.service - containerd container runtime
   Loaded: loaded (/etc/systemd/system/containerd.service; disabled; vendor preset: disabled)
   Active: active (running) since Mon 2017-11-20 19:02:48 CST; 6 days ago
     Docs: https://containerd.io
 Main PID: 31436 (containerd)
   Memory: 481.0M
   CGroup: /system.slice/containerd.service
           ├─  353 containerd-shim --namespace k8s.io --workdir /var/lib/containerd/io.containerd.runtime.v1.linux/k...
           ├─  524 containerd-shim --namespace k8s.io --workdir /var/lib/containerd/io.containerd.runtime.v1.linux/k...
           ├─  591 containerd-shim --namespace k8s.io --workdir /var/lib/containerd/io.containerd.runtime.v1.linux/k...
           ├─  625 containerd-shim --namespace k8s.io --workdir /var/lib/containerd/io.containerd.runtime.v1.linux/k...
           ├─  831 containerd-shim --namespace k8s.io --workdir /var/lib/containerd/io.containerd.runtime.v1.linux/k...
           ├─ 5066 containerd-shim --namespace k8s.io --workdir /var/lib/containerd/io.containerd.runtime.v1.linux/k...
           ├─ 5134 containerd-shim --namespace k8s.io --workdir /var/lib/containerd/io.containerd.runtime.v1.linux/k...
           ├─ 5451 containerd-shim --namespace k8s.io --workdir /var/lib/containerd/io.containerd.runtime.v1.linux/k...
           ├─ 9056 containerd-shim --namespace k8s.io --workdir /var/lib/containerd/io.containerd.runtime.v1.linux/k...
           ├─ 9595 containerd-shim --namespace k8s.io --workdir /var/lib/containerd/io.containerd.runtime.v1.linux/k...
           ├─ 9809 containerd-shim --namespace k8s.io --workdir /var/lib/containerd/io.containerd.runtime.v1.linux/k...
           ├─ 9991 containerd-shim --namespace k8s.io --workdir /var/lib/containerd/io.containerd.runtime.v1.linux/k...
           ├─10194 containerd-shim --namespace k8s.io --workdir /var/lib/containerd/io.containerd.runtime.v1.linux/k...
           ├─11532 n/a
           ├─18009 containerd-shim --namespace k8s.io --workdir /var/lib/containerd/io.containerd.runtime.v1.linux/k...
           ├─18620 containerd-shim --namespace k8s.io --workdir /var/lib/containerd/io.containerd.runtime.v1.linux/k...
           ├─20173 containerd-shim --namespace k8s.io --workdir /var/lib/containerd/io.containerd.runtime.v1.linux/k...
           ├─21220 containerd-shim --namespace k8s.io --workdir /var/lib/containerd/io.containerd.runtime.v1.linux/k...
           ├─27893 containerd-shim --namespace k8s.io --workdir /var/lib/containerd/io.containerd.runtime.v1.linux/k...
           ├─29233 containerd-shim --namespace k8s.io --workdir /var/lib/containerd/io.containerd.runtime.v1.linux/k...
           ├─31436 /usr/local/bin/containerd --log-level=debug
           ├─31575 containerd-shim --namespace k8s.io --workdir /var/lib/containerd/io.containerd.runtime.v1.linux/k...
           ├─31577 containerd-shim --namespace k8s.io --workdir /var/lib/containerd/io.containerd.runtime.v1.linux/k...
           ├─31578 containerd-shim --namespace k8s.io --workdir /var/lib/containerd/io.containerd.runtime.v1.linux/k...
           ├─31619 containerd-shim --namespace k8s.io --workdir /var/lib/containerd/io.containerd.runtime.v1.linux/k...
           ├─31844 containerd-shim --namespace k8s.io --workdir /var/lib/containerd/io.containerd.runtime.v1.linux/k...
           ├─31892 containerd-shim --namespace k8s.io --workdir /var/lib/containerd/io.containerd.runtime.v1.linux/k...
           ├─31901 containerd-shim --namespace k8s.io --workdir /var/lib/containerd/io.containerd.runtime.v1.linux/k...
           ├─31918 containerd-shim --namespace k8s.io --workdir /var/lib/containerd/io.containerd.runtime.v1.linux/k...
           └─32765 containerd-shim --namespace k8s.io --workdir /var/lib/containerd/io.containerd.runtime.v1.linux/k...

is there something wrong about "ctr containers ls"？please give me some helps .

[dnephin]

containerd has namespaces: https://github.com/containerd/containerd/blob/master/README.md#namespaces

ctr --namespace k8s.io containers ls

[teijinyer]

I can use the command ctr --namespace k8s.io containers to get some info about container ，but i get nothing info when i use the command ctr --namespace k8s.io containers ls .

$ ctr containers ls
CONTAINER IMAGE RUNTIME
$ ctr --namespace k8s.io containers
CONTAINER IMAGE RUNTIME
0897f8ee16f7d16d2ef03661b4d6d4f3f5e5b294402812568fed463dc7e0c4c0 docker.io/library/nginx:latest io.containerd.runtime.v1.linux
0ca923c708a7e3362b195f4f494954675af14ea287eb344de44d764a41c9ce70 docker.io/yingtony/calico-etcd:2.2.1 io.containerd.runtime.v1.linux
12950d6b0a16eb5cd288774084c8db406b9ff5147994e9ec737b04fd8f82b509 docker.io/yingtony/kube-proxy-amd64:v1.8.3 io.containerd.runtime.v1.linux
13cc0fc44607e6f77c83fda0a2e0e9bc21c694598373417b850fd55352e49906 docker.io/yingtony/kube-controller-manager-amd64:v1.8.3 io.containerd.runtime.v1.linux

[AkihiroSuda]

In older versions of CLI, there was no ctr containers ls but ctr containers <filter>.
So ctr containers ls had shown containers that match the ls filter string.

[czm4514]

@AkihiroSuda
thank you very much