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https://github.com/jlesquembre/kubeprompt

Isolated kubectl shells and prompt info
https://github.com/jlesquembre/kubeprompt

kubeconfig kubectl kubectx kubernetes shell-prompt

Last synced: 26 days ago
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Isolated kubectl shells and prompt info

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# kubeprompt



[![Built with Nix](https://builtwithnix.org/badge.svg)](https://builtwithnix.org)



Isolates KUBECONFIG in each shell and shows the current Kubernetes

context/namespace in your prompt



![prompt](imgs/kubeprompt.png)



## Installation



### Manual install



Pre-built binaries are available for linux and MacOS on the

[releases](https://github.com/jlesquembre/kubeprompt/releases) page.



### Homebrew (macOS and Linux)



```bash

brew tap jlesquembre/kubeprompt https://github.com/jlesquembre/kubeprompt/

brew install kubeprompt

```



### NixOS



`kubeprompt` is available in the

[Nix Packages collection](https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/tools/kubeprompt/default.nix).



To install it globally, add it to your `systemPackages`. If you just want to try

it, you can do it in a Nix shell:



```bash

nix-shell -p kubeprompt

```



## Usage



`kubeprompt` is shell-agnostic and thus works on any shell, but every shell has

a different way to customize its prompt. Some examples:



fish shell:



```sh

function fish_prompt

  echo (kubeprompt -f default) '>'

end

```



Zsh:



```sh

PROMPT='$(kubeprompt -f default)'$PROMPT

```



Bash:



```sh

PS1="[\u@\h \W \$(kubeprompt -f default)]\$ "

```



`kubeprompt` will print to stdout information about the current cluster, but

first it needs to be _enabled_. It is considered enabled if the environment

variable `KUBECONFIG` is set to a file in the `$TMP/kubeprompt` directory. To

enable it, just execute `kubeprompt`. This will spawn a new shell (based on your

`SHELL` environment variable) and will copy your current kubeconfig to a new

temporary file (it uses [k8s cli-runtime][])



`kubeprompt` command will print the current K8S context and namespace, if

kubeprompt is enabled. If not, it will start a sub shell with kubeprompt

enabled. The sub shell to launch depends on the value of the environment

variable `SHELL`, starting a `bash` shell if is not defined.



To _disable_ `kubeprompt` you just need to got back to the previous shell. You

can do that with the `exit` command or with the `CTRL+d` shortcut.



Valid flags:



- `-f`, `--format` custom format string

- `-t`, `--temp-config` copies the current KUBECONFIG to a temporary file, used

  with [direnv][]

- `-c`, `--check` print information about kubeprompt status

- `-h`, `--help` help for kubeprompt

- `-v`, `--version` print the version



## Usage with direnv



From version 0.4, `kubeprompt` can be integrated with [direnv][]. In this case,

there is no need to start a sub shell.



`.envrc` e.g.:



```bash

export KUBECONFIG=$(kubeprompt -t)



# Only required if you want to set the K8S context

kubectx minikube

```



If you use [direnv][] with [nix][] (you should!), use this instead:



`shell.nix`:



```nix

with import  { };

pkgs.mkShell {

  buildInputs = [

    # ...

  ];

  shellHook = ''

    export KUBECONFIG=$(kubeprompt -t)

    kubectx minikube

  '';

}

```



See [direnv Wiki: Nix integration](https://github.com/direnv/direnv/wiki/Nix)

for more info.



[direnv][] limitations: It is not possible to clean up the temporary KUBECONFIG

files created when you exit the shell. But those temporary files are usually

deleted when you shutdown your system. If you don't use [direnv][] and spawn a

new subshell with `kubeprompt`, the temporary files are deleted after you exit

the subshell.



## Integration with other tools



`kubeprompt` tries to leverage and complement existing tools.



To read and create a copy of your `KUBECONFIG`, it uses [k8s cli-runtime][]. You

can expect the same behavior as with the `kubectl` command.



It plays well with [kubectx][], since it uses `kubectl` under the hood.



For the same reason, it also plays well with [k9s][].



## Prompt customization



It is possible to customize the prompt using go templates. The templates have

access to 3 variables, `Ctx`, `Ns` and `Enabled`, and to the

[color functions provided by Aurora](https://github.com/logrusorgru/aurora#standard-and-bright-colors),

plus the `Bold`, `Faint`, `Italic` and `Underline` functions.



The default format is



```go

{{if .Enabled}}(K8S {{.Ctx | Yellow | Bold}}|{{.Ns | Magenta | Bold}}){{end}}

```



You have 2 options to provide your format string, with `-f` / `--format` option,

or setting the environment variable `KUBEPROMPT_FORMAT`. If both are provided,

`-f` is used.



Some examples:



- No colors:



```go

'(⎈ {{.Ctx}}|{{.Ns}})'

```



- Print only if kubeprompt is enabled:



```go

'{{if .Enabled}}{{"⎈" | Black | BgWhite }} {{.Ctx}}|{{.Ns}}{{end}}'

```



- Print `k8s` string with a different color if kubeprompt is enabled:



```go

'{{if .Enabled}}{{"k8s"|Green|Bold}}{{else}}{{"k8s"|Red}}{{end}} {{.Ctx}}|{{.Ns}}'

```



## Workflows



Usually you'll call `kubeprompt -f default` in your dot files. In the terminal,

you usually want to call `kubeprompt` to enable it, because after it, you can be

confident about the information in your terminal, since every terminal will have

its own isolated kubeconfig.



You can decide if you want to show the kubernetes information always or only

when _kubeprompt_ is enabled. If you want to show the information always, I

recommend to use different colors to know if _kubeprompt_ is enabled or not. I

consider the disabled color as a warning, because in this case, you cannot be

sure if the information is accurate. Since your kubeconfig is global, other

applications (or yourself in other terminal) can change the global kubernetes

context.



## F.A.Q.



### Why to copy kubeconfig and start a sub shell?



If you are working with multiple contexts/namespaces in multiple terminals, all

of them will modify the same kubeconfig file when you update the

context/namespace. For more context, see

[kubernetes PR #60044](https://github.com/kubernetes/kubernetes/pull/60044#issuecomment-405420482)



Let's suppose that you are working in 2 terminals with `kubectl` in context

_foo_. Since you are using `kubeprompt`, your prompt shows that the context is

_foo_. Now, you change the context in one terminal to _bar_, and after it you

change the focus to the other terminal. Since the prompt information is static,

in that terminal the prompt still says that the context is _foo_, but that

information is old, and you could execute a command in the wrong context.



To avoid it, `kubeprompt` creates a copy of your current kubeconfig per terminal

and sets the `KUBECONFIG` environment variable to that copy. If now you change

the context or the namespace, only that terminal will be affected. If you want

to disable `kubeprompt` on one terminal, you just need to press `CTRL+d`



## Related tools



- [kubectx][]

- [k9s][]

- [kube-ps1](https://github.com/jonmosco/kube-ps1)

- [fish-kubectl-prompt](https://github.com/Ladicle/fish-kubectl-prompt)

- [kubie](https://github.com/sbstp/kubie)



[k8s cli-runtime]: https://github.com/kubernetes/cli-runtime

[kubectx]: https://github.com/ahmetb/kubectx

[k9s]: https://github.com/derailed/k9s

[direnv]: https://direnv.net/

[nix]: (https://nixos.org/)