kubecolor: add shell completion support (#345483)

{ lib, buildGoModule, fetchFromGitHub }:

{ lib, stdenv, buildGoModule, fetchFromGitHub, kubectl, installShellFiles }:

buildGoModule rec {

  pname = "kubecolor";

    "."

  ];

  nativeBuildInputs = [ installShellFiles ];

  postInstall = lib.optionalString (stdenv.buildPlatform.canExecute stdenv.hostPlatform) ''

    # kubecolor re-uses the completions of kubectl for its own executable

    installShellCompletion --cmd kubecolor \

      --bash <(${lib.getExe kubectl} completion bash) \

      --fish <(${lib.getExe kubectl} completion fish) \

      --zsh <(${lib.getExe kubectl} completion zsh)

    # https://kubecolor.github.io/setup/shells/bash/

    echo 'complete -o default -F __start_kubectl kubecolor' >> $out/share/bash-completion/completions/kubecolor.bash

    # https://kubecolor.github.io/setup/shells/fish/

    echo -e 'function kubecolor --wraps kubectl\n  command kubecolor $argv\nend' >> $out/share/fish/vendor_completions.d/kubecolor.fish

    # https://kubecolor.github.io/setup/shells/zsh/

    echo 'compdef kubecolor=kubectl' >> $out/share/zsh/site-functions/_kubecolor

  '';

  meta = with lib; {

    description = "Colorizes kubectl output";

    mainProgram = "kubecolor";