Mcrouter Operator powered by Ansible Operator (step 2): telnet image does not work

[troppens]

The module uses the jess/telnet image which is broken: jessfraz/dockerfiles#547

The impact for this learning module is that the command hangs forever and for OpenShift beginners it is hard to identify the root cause and to find a workaround.

I resolved it for myself by creating my own container image as described in the issue above.

The following command is hanging forever:

$ oc run -it --rm telnet --image=jess/telnet --restart=Never mcrouter 5000

Here are the logs:

$ oc get pods
NAME                                 READY   STATUS                 RESTARTS   AGE
mcrouter-7656564544-76fw7            1/1     Running                0          113s
mcrouter-memcached-0                 1/1     Running                0          116s
mcrouter-memcached-1                 1/1     Running                0          105s
mcrouter-operator-59ccfcb8d9-t5vdr   2/2     Running                0          3m19s
telnet                               0/1     CreateContainerError   0          85s
$ oc logs pods/telnet
Error from server (BadRequest): container "telnet" in pod "telnet" is waiting to start: CreateContainerError
$ oc describe pods/telnet
Name:         telnet
Namespace:    mcrouter
Priority:     0
Node:         crc-rtgqw-master-0/192.168.126.11
Start Time:   Sat, 05 Sep 2020 09:51:44 +0000
Labels:       run=telnet
Annotations:  k8s.v1.cni.cncf.io/networks-status:
                [{
                    "name": "openshift-sdn",
                    "interface": "eth0",
                    "ips": [
                        "10.128.0.69"
                    ],
                    "dns": {},
                    "default-route": [
                        "10.128.0.1"
                    ]
                }]
              openshift.io/scc: anyuid
Status:       Pending
IP:           10.128.0.69
IPs:
  IP:  10.128.0.69
Containers:
  telnet:
    Container ID:
    Image:         jess/telnet
    Image ID:
    Port:          <none>
    Host Port:     <none>
    Args:
      mcrouter
      5000
    State:          Waiting
      Reason:       CreateContainerError
    Ready:          False
    Restart Count:  0
    Environment:    <none>
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-vk2lg (ro)
Conditions:
  Type              Status
  Initialized       True
  Ready             False
  ContainersReady   False
  PodScheduled      True
Volumes:
  default-token-vk2lg:
    Type:        Secret (a volume populated by a Secret)
    SecretName:  default-token-vk2lg
    Optional:    false
QoS Class:       BestEffort
Node-Selectors:  <none>
Tolerations:     node.kubernetes.io/not-ready:NoExecute for 300s
                 node.kubernetes.io/unreachable:NoExecute for 300s
Events:
  Type     Reason     Age        From                         Message
  ----     ------     ----       ----                         -------
  Normal   Scheduled  <unknown>  default-scheduler            Successfully assigned mcrouter/telnet to crc-rtgqw-master-0
  Warning  Failed     101s       kubelet, crc-rtgqw-master-0  Error: container create failed: time="2020-09-05T09:51:51Z" level=error msg="container_linux.go:349: starting container process caused \"exec: \\\"telnet\\\": executable file not found in $PATH\""
container_linux.go:349: starting container process caused "exec: \"telnet\": executable file not found in $PATH"
  Warning  Failed  98s  kubelet, crc-rtgqw-master-0  Error: container create failed: time="2020-09-05T09:51:55Z" level=error msg="container_linux.go:349: starting container process caused \"exec: \\\"telnet\\\": executable file not found in $PATH\""
container_linux.go:349: starting container process caused "exec: \"telnet\": executable file not found in $PATH"
  Warning  Failed  81s  kubelet, crc-rtgqw-master-0  Error: container create failed: time="2020-09-05T09:52:12Z" level=error msg="container_linux.go:349: starting container process caused \"exec: \\\"telnet\\\": executable file not found in $PATH\""
container_linux.go:349: starting container process caused "exec: \"telnet\": executable file not found in $PATH"
  Warning  Failed  65s  kubelet, crc-rtgqw-master-0  Error: container create failed: time="2020-09-05T09:52:28Z" level=error msg="container_linux.go:349: starting container process caused \"exec: \\\"telnet\\\": executable file not found in $PATH\""
container_linux.go:349: starting container process caused "exec: \"telnet\": executable file not found in $PATH"
  Warning  Failed  49s  kubelet, crc-rtgqw-master-0  Error: container create failed: time="2020-09-05T09:52:44Z" level=error msg="container_linux.go:349: starting container process caused \"exec: \\\"telnet\\\": executable file not found in $PATH\""
container_linux.go:349: starting container process caused "exec: \"telnet\": executable file not found in $PATH"
  Warning  Failed  32s  kubelet, crc-rtgqw-master-0  Error: container create failed: time="2020-09-05T09:53:01Z" level=error msg="container_linux.go:349: starting container process caused \"exec: \\\"telnet\\\": executable file not found in $PATH\""
container_linux.go:349: starting container process caused "exec: \"telnet\": executable file not found in $PATH"
  Normal   Pulled  15s (x7 over 102s)  kubelet, crc-rtgqw-master-0  Successfully pulled image "jess/telnet"
  Warning  Failed  15s                 kubelet, crc-rtgqw-master-0  Error: container create failed: time="2020-09-05T09:53:18Z" level=error msg="container_linux.go:349: starting container process caused \"exec: \\\"telnet\\\": executable file not found in $PATH\""
container_linux.go:349: starting container process caused "exec: \"telnet\": executable file not found in $PATH"
  Normal  Pulling  2s (x8 over 107s)  kubelet, crc-rtgqw-master-0  Pulling image "jess/telnet"
$

Here is my work-around, using my own image:

$ oc delete pods/telnet
pod "telnet" deleted
$ oc run -it --rm telnet --image=troppens/telnet --restart=Never mcrouter 5000
If you don't see a command prompt, try pressing enter.
set ansible 0 0 8
operator
STORED
get ansible
VALUE ansible 0 8
operator
END
quit
Connection closed by foreign host
pod "telnet" deleted
pod mcrouter/telnet terminated (Error)
$

My image is available on Docker Hub and Quay. I am happy to provide a pull request using my image, if this is of interest for the community.

[madorn]

@troppens Hi Ulf, thanks for reporting this and sorry for the delay in getting back to you.

If you'd like to submit a PR with your quay telnet image, it would be greatly appreciated!