kran exec

Usagekran exec [-i|--interactive] [--] COMMAND...

Find a running pod matching app.selector and run a command in it.

Options

The command it runs

$ kran exec bin/rails db:migrate --dry-run
pod=$(KUBECONFIG=/home/dana/.kube/prod-east.yml kubectl --context prod-east --namespace storefront get pods -l app=storefront --field-selector status.phase=Running -o 'jsonpath={.items[0].metadata.name}') && test -n "$pod" || { echo 'No running pod matches app=storefront' >&2; exit 1; }
KUBECONFIG=/home/dana/.kube/prod-east.yml kubectl --context prod-east --namespace storefront exec "$pod" -- bin/rails db:migrate

The first line asks for the first pod matching the selector that is in phase Running, because a Pending, Terminating or CrashLoopBackOff pod cannot accept an exec.

With -i the second command becomes kubectl exec -it "$pod" -- .... With app.container set it gains -c <container>.

Flags for your command

$ kran exec -- bin/rails runner -e production 'puts Rails.env' --dry-run
... exec "$pod" -- bin/rails runner -e production 'puts Rails.env'

Use -- when your command has flags. Kran parses its own options first, so without it -e is taken as a kran option and rejected.

$ kran exec
ERROR: exec needs a command to run, for example `kran exec bin/rails db:migrate`
$ kran exec bin/rails db:migrate
No running pod matches app=storefront

Which pod

The first running match the API returns; there is no ordering guarantee. To reach a specific pod, use kubectl exec with a name from kran details.

shell and console

The template’s two aliases are ordinary kran exec calls: exec --interactive bash and exec --interactive bin/rails console. See Aliases.