K
Q

How to list all containers running in a pod, including init containers?

11/2/2017

A solution to retrieve all containers running in a pod is to run kubectl get pods POD_NAME_HERE -o jsonpath={.spec.containers[*].name}, however this command line does not provide the init containers.

Is there a way to cleanly retrieve all containers running in a pod, including init containers?

[edit] as svenwltr noted, on Kubernete 1.6.0 or higher, it is possible to retrieve the init container with kubectl get pods POD_NAME_HERE -o jsonpath={.spec.initContainers[*].name} and all containers can be retrieved with kubectl get pod POD_NAME_HERE -o jsonpath="{.spec['containers','initContainers'][*].name}". However, this is not a valid workaround for lower versions of Kubernetes where .spec.initContainers isn't implemented yet.

-- Pauline
kubernetes

Similar Questions

redis-ha : Unable to create specified number of masters in cluster
Unable to delete or create azure aks instances
Both public and intranet services on the same OpenShift cluster
Kops/Kubernetes how to add simple image to the cluster

2 Answers

11/2/2017

Another way to do this is to use kubectl describe pod <POD_NAME_HERE>. This will print the Init Containers in a separate section from the regular Containers of your pod.

Example:

$ kubectl describe pod myapp-pod
Name:       myapp-pod
Namespace:  default
[...]
Init Containers:
  init-myservice:
    Container ID:   docker://87c2601c9f18b4e9d63f995e03d83338e1321e016e76798243257d3e682256c2
    Image:      busybox
    Image ID:       docker-pullable://busybox@sha256:3841678eb5ddd5b62fec74d7f530fe633ee7cf11d4e3827c0b74e2e4c2a2466f
    Port:       <none>
    Command:
      sh
      -c
      until nslookup myservice; do echo waiting for myservice; sleep 2; done;
    State:      Running
      Started:      Thu, 02 Nov 2017 10:54:01 -0400
    Ready:      False
    Restart Count:  0
    Requests:
      cpu:      100m
    Environment:    <none>
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-38lv5 (ro)
  init-mydb:
    Container ID:
    Image:      busybox
    Image ID:
    Port:       <none>
    Command:
      sh
      -c
      until nslookup mydb; do echo waiting for mydb; sleep 2; done;
    State:      Waiting
      Reason:       PodInitializing
    Ready:      False
    Restart Count:  0
    Requests:
      cpu:      100m
    Environment:    <none>
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-38lv5 (ro)
Containers:
  myapp-container:
    Container ID:
    Image:      busybox
    Image ID:
    Port:       <none>
    Command:
      sh
      -c
      echo The app is running! && sleep 3600
    State:      Waiting
      Reason:       PodInitializing
    Ready:      False
    Restart Count:  0
    Requests:
      cpu:      100m
    Environment:    <none>
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-38lv5 (ro)
[...]
-- RochesterinNYC
Source: StackOverflow
11/2/2017

The init containers are stored in spec.initContainers:

kubectl get pods POD_NAME_HERE -o jsonpath={.spec.initContainers[*].name}

You can display both with a bit of JSONPath magic:

kubectl get pod POD_NAME_HERE -o jsonpath="{.spec['containers','initContainers'][*].name}"

Before Kubernetes 1.6 the init containers were stored in .metadata.annotations."pod.beta.kubernetes.io/init-containers". So it should be possible to get them via:

kubectl get pods POD_NAME_HERE -o jsonpath='{metadata.annotations."pod.beta.kubernetes.io/init-containers".[*].name}'

Unfortunately I cannot test this, because I don't have a cluster with this version. Also joining containers and init containers into a single command looks a bit harder this way.

-- svenwltr
Source: StackOverflow