/kubectl-mo

Executes `kubectl get ...` command for multiple namespaces to get any resource you want.

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kubectl-mo

Executes kubectl get ... command for multiple namespaces to get any resource you want.

Feature 1: Execute kubectl get ... in current and last namespace

Pre-requisites

  • kubens (kubectl-mo uses information stored by kubens to figure out the last used namespace)

For example, let's say your current namespace is kube-system:

$ kubectl config view --minify -o jsonpath='{..namespace}'
kube-system

You change the namespace to default using kubens:

$ kubens default
Context "k3d-dynamic-corefile" modified.
Active namespace is "default".

Now, if you want to get any resource from the current and the last namespace, you can use kubectl-mo like this:

$ kubectl mo get configmaps
executing command /home/suraj/bin/kubectl -n default get configmaps
NAME               DATA   AGE
kube-root-ca.crt   1      33d

executing command /home/suraj/bin/kubectl -n kube-system get configmaps
NAME                                 DATA   AGE
extension-apiserver-authentication   6      33d
cluster-dns                          2      33d
local-path-config                    4      33d
chart-content-traefik                0      33d
chart-values-traefik                 1      33d
chart-content-traefik-crd            0      33d
chart-values-traefik-crd             0      33d
kube-root-ca.crt                     1      33d
coredns                              2      33d

$ kubectl mo get pods
executing command /home/suraj/bin/kubectl -n default get po
NAME    READY   STATUS    RESTARTS       AGE
nginx   1/1     Running   14 (53m ago)   11d

executing command /home/suraj/bin/kubectl -n kube-system get po
NAME                                      READY   STATUS      RESTARTS        AGE
helm-install-traefik-crd-vplbc            0/1     Completed   0               33d
helm-install-traefik-q26gv                0/1     Completed   1               33d
local-path-provisioner-7b7dc8d6f5-q8k6x   1/1     Running     51 (53m ago)    33d
coredns-b96499967-tmswr                   1/1     Running     51 (53m ago)    33d
svclb-traefik-98312b71-66crq              2/2     Running     121 (53m ago)   33d
traefik-7cd4fcff68-dt82t                  1/1     Running     51 (53m ago)    33d
metrics-server-668d979685-tbblc           1/1     Running     51 (53m ago)    33d

In general, you can use:

$ kubectl mo get <any-resource> <flags>

To execute any kubectl get ... command with flags in your current and last namespace.

Feature 2: Execute kubectl get ... in multiple namespaces

Pre-requisites

  • none (you can use this feature without kubens)

Instead of running kubectl get ... in the current and the last namespace, you want to run kubectl get ... in arbitrary multiple namespaces, you can do:

$ kubectl mo get configmaps  -ns=kube-public,kube-node-lease
executing command /home/suraj/bin/kubectl -n kube-public get configmaps
NAME               DATA   AGE
kube-root-ca.crt   1      33d

executing command /home/suraj/bin/kubectl -n kube-node-lease get configmaps
NAME               DATA   AGE
kube-root-ca.crt   1      33d

In general,

$ kubectl mo get <any-resource> <flags> -ns=ns1,ns2...

If you add -ns flag kubectl-mo doesn't execute kubectl get ... in the current and the last namespace.

Good to know

  • kubectl-mo uses the kubectl binary available on the user's machine. This is intentional. We want kubectl-mo to be compatible with different versions of kubectl.

What problem is kubectl-mo trying to solve?

  • When you are working with kubernetes, you often want to see resources in multiple namespaces but kubectl doesn't give you that functionality. To be specific, you often want one of the following:
    1. Look for resources in your current and the last used namespace to avoid constantly switching namespaces
    2. Look for resources in your current and last N namespaces
    3. Look for resources in arbitrary multiple namespaces
  • There have been issues filed around this but there doesn't seem to be any progress on solving this problem in the upstream kubectl code:
  • There have been attempts to solve this problem using a plugin:

Cons

  • If you have too many resources in your namespaces, using kubectl-mo get might take time to execute because the underlying kubectl get ... takes time to execute.

Feedback

We'd love to know what you think about the plugin. Feel free to create an issue to give us feedback, suggestions, file bugs or ask for new features.

Future scope

  • It would be nice to have a way to let kubectl-mo figure out the last 5 namespaces that the user used. This includes the namespaces user switched to (using say kubens) and also the namespaces user used in their kubectl command using --namespace or -n flag. kubectl-mo can then automatically query for resources in those last 5 namespaces.
  • It would be nice if the user can specify namespaces once and kubectl-mo uses the namespaces in subsequent commands. For example:
$ kubectl mo get po -ns=default,kube-system
# kubectl mo saves `default` and `kube-system` namespaces
$ kubectl-mo get po # no need to specify `-ns` again

$ kubectl mo get po -ns=dev,prod
# kubectl-mo overwrites last saved namespaces i.e., `default` and `kube-system` with `dev` and `prod`
$ kubectl mo get po # no need to specify `-ns` again

Note: Future scope will be worked upon based on user interest