Kubectl REPL

Wrap kubectl with namespace and variables. Run commands in current namespace without copy and pasting all the time!

Installation

Download latest release for your platform from https://github.com/Mikulas/kubectl-repl/releases. It's recommended to use rlwrap in combination with kubectl-repl, such as rlwrap kubectl-repl. This adds prompt history, search, buffering etc.

Docker image with prebuilt binary can be downloaded with docker pull mikulas/kubectl-repl (Docker Hub). Requires volume mount into /root/.kube, for example -v ~/.kube:/root/.kube:ro. Docker image already includes rlwrap, but does not persist command history across multiple containers.

Alternatively, download and build locally: see Makefile (make build).

Usage

./kubectl-repl first starts by asking you for namespace. You may enter any of the strings verbatim, or any abbreviation that is closest. You may also use any of the variables REPL assigned ($2, more on that in #variables).

Then you are in the main REPL mode. You are presented with a prompt, into which you enter kubectl commands (kubectl -n $NS prefix is implied).

Namespace can be changed by calling namespace or ns repl builtin, optionally with namespace abbreviation to change to: ns $pattern.

The prompt can be exited with traditional eof ^D or sigint ^C, and an explicit quit or exit builtin command. If a command spawned long living process (such as --follow, --watch or exec), sigint will terminate the processes first and return to repl.

To manage multiple clusters concurrently, it's possible to invoke repl with a -context=$CTX option. This overrides current context set in your kubeconfig. You can run multiple repls at once with different context. For simple context management (and renaming), I recommend ahmetb/kubectx.

Compatibility

All commands are passed either to kubectl or to your shell. That means you only have to upgrade your other tooling to support different Kubernetes versions. This repl does not introduce additional compatibility restrictions.

Shell integration

Instead of directly invoking kubectl with prompt as arguments, /bin/sh -c is used. This allows for more complex usage usage as grep and redirects:

# sentry get pods | grep app
+ kubectl -n sentry get pods | grep app
$1 	app-deployment-314667899-4r9c1       1/1       Running   0          22h
$2 	app-deployment-314667899-xr47k       1/1       Running   0          22h
# sentry get pods -o json > /tmp/pods.json
+ kubectl -n sentry get pods -o json > /tmp/pods.json

Raw shell invocation is also supported by prefixing the command with ;. This should be intuitive as it works in shell by default. Repl integration does not prefix the shell with kubectl -n $NS in this mode and trims the semicolon. Repl variables are available as in all other prompt modes.

# kube-system get pods
+ kubectl -n kube-system get pods
   	NAME                        READY     STATUS    RESTARTS   AGE
$1 	kube-dns-3945342221-mwdh6   3/3       Running   0          9d
$2 	kube-dns-3945342221-x3fhn   3/3       Running   0          9d
# kube-system ; echo $(whoami) $2
+  echo $(whoami) kube-dns-3945342221-x3fhn
mikulas kube-dns-3945342221-x3fhn

Variables

Prompts starting with get return their output prefixed with $n. You may use those variables anywhere to automatically substitute for the value of the first column of the respective line. For example:

# sentry get pods
+ kubectl -n sentry get pods
   	NAME                                 READY     STATUS    RESTARTS   AGE
$1 	app-deployment-314667899-4r9c1       1/1       Running   0          22h
$2 	app-deployment-314667899-xr47k       1/1       Running   0          22h
# sentry logs $2
+ kubectl -n sentry logs app-deployment-314667899-xr47k

The $2 was substituted for app-deployment-314667899-xr47k.

Builtin variables have priority before shell variables from env, but both can be used:

$ env TYPE=pod rlwrap ./kubectl-repl -verbose
# default get $TYPE
+ kubectl -n default get $TYPE

Furthermore, you can also access the other columns with a $n:index syntax. Without a column $n defaults to $n:1.

# beta kube-system get pods --all-namespaces
  	NAMESPACE        NAME                READY STATUS   RESTARTS  AGE
$1 	kube-monitoring  logspout-ds-9l4pw   1/1   Running  36        4d
$2 	kube-monitoring  logspout-ds-b2pws   1/1   Running  9         3d
$3 	kube-monitoring  logspout-ds-gs4nv   1/1   Running  0         4d
# beta kube-system ; echo $1
kube-monitoring
# beta kube-system ; echo $1:2
logspout-ds-9l4pw

Alternatives

• https://github.com/c-bata/kube-prompt