Merge pull request #32 from shiroyasha/installation-steps-linux

Example installation steps on Linux

Formula/kubectx.rb

@@ -1,18 +0,0 @@
-class Kubectx < Formula
-  desc "Tool that can switch between kubectl contexts easily and create aliases"
-  homepage "https://github.com/ahmetb/kubectx"
-  url "https://github.com/ahmetb/kubectx/archive/v0.2.0.tar.gz"
-  sha256 "9fb6557416e4be3ef7e9701527f89fa73a1a0545a3cafbe6bed7527061c6cfb7"
-
-  bottle :unneeded
-
-  def install
-    bin.install "kubectx"
-    bash_completion.install "completion/kubectx.bash" => "kubectx"
-    zsh_completion.install "completion/kubectx.zsh" => "_kubectx"
-  end
-
-  test do
-    system "which", "kubectx"
-  end
-end

README.md

@@ -1,3 +1,12 @@
+This repository provides both `kubectx` and `kubens` tools.
+
+
+**`kubectx`** help you switch between clusters back and forth:
+![kubectx demo GIF](img/kubectx-demo.gif)
+
+**`kubens`** help you switch between Kubernetes namespaces smoothly:
+![kubens demo GIF](img/kubens-demo.gif)
+
 # kubectx(1)
 
 kubectx is an utility to manage and switch between kubectl(1) contexts.
@@ -5,16 +14,13 @@ kubectx is an utility to manage and switch between kubectl(1) contexts.
 ```
 USAGE:
   kubectx                   : list the contexts
-  kubectx <NAME>            : switch to context
+  kubectx <NAME>            : switch to context <NAME>
   kubectx -                 : switch to the previous context
-  kubectx <NEW_NAME>=<NAME> : create alias for context
+  kubectx <NEW_NAME>=<NAME> : rename context <NAME> to <NEW_NAME>
   kubectx -h,--help         : show this message
 ```
 
-Purpose of this project is to provide an utility and facilitate discussion
-about how `kubectl` can manage contexts better.
-
-## Example
+### Usage
 
 ```sh
 $ kubectx minikube
@@ -31,12 +37,100 @@ Context "dublin" set.
 Aliased "gke_ahmetb_europe-west1-b_dublin" as "dublin".
 ```
 
-[Set up `bash` and `zsh` completion &rarr;](completion/README.md)
+`kubectx` supports <kbd>Tab</kbd> completion on bash/zsh/fish shells to help with
+long context names. You don't have to remember full context names anymore.
 
-### Help wanted
+-----
 
-- [ ] homebrew formula/tap that installs the script and completions
+# kubens(1)
+
+kubens is an utility to switch between Kubernetes namespaces.
+
+```
+USAGE:
+  kubens                    : list the namespaces
+  kubens <NAME>             : change the active namespace
+  kubens -                  : switch to the previous namespace
+  kubens -h,--help          : show this message
+```
+
+
+### Usage
+
+```sh
+$ kubens kube-system
+Context "test" set.
+Active namespace is "kube-system".
+
+$ kubens -
+Context "test" set.
+Active namespace is "default".
+```
+
+`kubens` also supports <kbd>Tab</kbd> completion on bash/zsh/fish shells.
+
+-----
+
+## Installation
+
+**macOS:**
+
+:confetti_ball: Use the [Homebrew](https://brew.sh/) package manager:
+
+    brew install kubectx
+
+This command will set up bash/zsh/fish completion scripts automatically.
+
+
+- Running `brew install` with `--with-short-names` will install tools with names
+`kctx` and `kns` to prevent prefix collision with `kubectl` name.
+
+- If you like to add context/namespace info to your shell prompt (`$PS1`),
+  I recommend trying out [kube-ps1](https://github.com/jonmosco/kube-ps1).
+
+**Linux:**
+
+Since `kubectx`/`kubens` are written in Bash, you should be able to instal
+them to any POSIX environment that has Bash installed.
+
+- Download the `kubectx`, and `kubens` scripts.
+- Either:
+  - save them all to somewhere in your `PATH`,
+  - or save them to a directory, then create symlinks to `kubectx`/`kubens` from
+    somewhere in your `PATH`, like `/usr/local/bin`
+- Make `kubectx` and `kubens` executable (`chmod +x ...`)
+- Figure out how to install bash/zsh/fish [completion scripts](completion/).
+
+Example installation steps:
+
+``` bash
+sudo git clone https://github.com/ahmetb/kubectx /opt/kubectx
+sudo ln -s /opt/kubectx/kubectx /usr/local/bin/kubectx
+sudo ln -s /opt/kubectx/kubens /usr/local/bin/kubens
+```
+
+-----
+
+####  Users
+
+| What are others saying about kubectx? |
+| ---- |
+| _“Thank you for kubectx & kubens - I use them all the time & have them in my k8s toolset to maintain happiness :) ”_ – [@pbouwer](https://twitter.com/pbouwer/status/925896377929949184) |
+| _“I can't imagine working without kubectx and especially kubens anymore. It's pure gold.”_ – [@timoreimann](https://twitter.com/timoreimann/status/925801946757419008) |
+| _“I'm liking kubectx from @ahmetb, makes it super-easy to switch #Kubernetes contexts [...]”_ &mdash; [@lizrice](https://twitter.com/lizrice/status/928556415517589505) |
+| _“Also using it on a daily basis. This and my zsh config that shows me the current k8s context 😉”_ – [@puja108](https://twitter.com/puja108/status/928742521139810305) |
+| _“Lately I've found myself using the kubens command more than kubectx. Both very useful though :-)”_ – [@stuartleeks](https://twitter.com/stuartleeks/status/928562850464907264) |
+| _“yeah kubens rocks!”_ – [@embano1](https://twitter.com/embano1/status/928698440732815360) |
+| _“Special thanks to Ahmet Alp Balkan for creating kubectx, kubens, and kubectl aliases, as these tools made my life better.”_ – [@strebeld](https://medium.com/@strebeld/5-ways-to-enhance-kubectl-ux-97c8893227a)
+
+> If you liked `kubectx`, you may like my [`kubectl-aliases`](https://github.com/ahmetb/kubectl-aliases) project, too.
 
 -----
 
 Disclaimer: This is not an official Google product.
+
+
+#### Stargazers over time
+
+[![Stargazers over time](https://starcharts.herokuapp.com/ahmetb/kubectx.svg)](https://starcharts.herokuapp.com/ahmetb/kubectx)
+

completion/README.md

@@ -1,45 +0,0 @@
-kubectx provides shell completion scripts to complete context names, making it
-even faster to switch between contexts easily.
-
-## Bash setup
-
-Copy the `kubectx.bash` file to your HOME directory:
-
-```sh
-cp kubectx.bash ~/.kubectx.bash
-```
-
-And source it in your `~/.bashrc` file by adding the line:
-
-```sh
-[ -f ~/.kubectx.bash ] && source ~/.kubectx.bash
-```
-
-Start a new shell, type `kubectx`, then hit <kbd>Tab</kbd> to see the existing
-contexts.
-
-You can Add `TAB: menu-complete` to your `~/.inputrc` to cycle through the
-options with <kbd>Tab</kbd>.
-
-## Zsh setup
-
-`zsh` can leverage the `bash` completion scripts. Copy the `kubectx.bash` file
-to your HOME directory:
-
-```sh
-cp kubectx.bash ~/.kubectx.bash
-```
-
-And add the following to your `.zshrc`:
-
-```sh
-[ -f ~/.kubectx.bash ] && source ~/.kubectx.bash
-```
-
-Start a new shell, type `kubectx`, then hit <kbd>Tab</kbd> to see the existing
-contexts. If it does not work, modify the line above to:
-
-```sh
-[ -f ~/.kubectx.bash ] && autoload bashcompinit && bashcompinit && \
-      source ~/.kubectx.bash
-```

completion/kubectx.bash

@@ -2,7 +2,7 @@ _kube_contexts()
 {
   local curr_arg;
   curr_arg=${COMP_WORDS[COMP_CWORD]}
-  COMPREPLY=( $(compgen -W "- $(kubectl config get-contexts | awk '{print $2}' | tail -n +2)" -- $curr_arg ) );
+  COMPREPLY=( $(compgen -W "- $(kubectl config get-contexts --output='name')" -- $curr_arg ) );
 }
 
-complete -F _kube_contexts kubectx
+complete -F _kube_contexts kubectx kctx

completion/kubectx.fish

@@ -0,0 +1,3 @@
+# kubectx
+complete -f -c kubectx -a "- (kubectl config get-contexts --output='name')"
+

completion/kubectx.zsh

@@ -1,12 +1,12 @@
-#compdef kubectx
+#compdef kubectx kctx=kubectx
 
-KUBECTX="${HOME}/.kube/kubectx"
+local KUBECTX="${HOME}/.kube/kubectx"
 PREV=""
 if [ -f "$KUBECTX" ]; then
     # show '-' only if there's a saved previous context
-    PREV=$(cat "${KUBECTX}")
-    _arguments "1: :((-\:Back\ to\ ${PREV} \
-        $(kubectl config get-contexts | awk '{print $2}' | tail -n +2)))"
+    local PREV=$(cat "${KUBECTX}")
+    _arguments "1: :((- \
+        $(kubectl config get-contexts --output='name')))"
 else
-    _arguments "1: :($(kubectl config get-contexts | awk '{print $2}' | tail -n +2))"
+    _arguments "1: :($(kubectl config get-contexts --output='name'))"
 fi

completion/kubens.bash

@@ -0,0 +1,8 @@
+_kube_namespaces()
+{
+  local curr_arg;
+  curr_arg=${COMP_WORDS[COMP_CWORD]}
+  COMPREPLY=( $(compgen -W "- $(kubectl get namespaces -o=jsonpath='{range .items[*].metadata.name}{@}{"\n"}{end}')" -- $curr_arg ) );
+}
+
+complete -F _kube_namespaces kubens kns

completion/kubens.fish

@@ -0,0 +1,3 @@
+# kubens
+complete -f -c kubens -a "(kubectl get ns -o=custom-columns=NAME:.metadata.name --no-headers)"
+

completion/kubens.zsh

@@ -0,0 +1,2 @@
+#compdef kubens kns=kubens
+_arguments "1: :(- $(kubectl get namespaces -o=jsonpath='{range .items[*].metadata.name}{@}{"\n"}{end}'))"

kubectx

@@ -27,9 +27,9 @@ usage() {
   cat <<"EOF"
 USAGE:
   kubectx                   : list the contexts
-  kubectx <NAME>            : switch to context
+  kubectx <NAME>            : switch to context <NAME>
   kubectx -                 : switch to the previous context
-  kubectx <NEW_NAME>=<NAME> : create alias for context
+  kubectx <NEW_NAME>=<NAME> : rename context <NAME> to <NEW_NAME>
   kubectx -h,--help         : show this message
 EOF
   exit 1
@@ -40,8 +40,7 @@ current_context() {
 }
 
 get_contexts() {
-  kubectl config view \
-    -o=jsonpath='{range .contexts[*].name}{@}{"\n"}{end}'
+  kubectl config get-contexts -o=name | sort -n
 }
 
 list_contexts() {
@@ -89,7 +88,6 @@ set_context() {
 }
 
 swap_context() {
-  set -e
   local ctx="$(read_context)"
   if [[ -z "${ctx}" ]]; then
     echo "error: No previous context found." >&2
@@ -108,7 +106,7 @@ cluster_of_context() {
     -o=jsonpath="{.contexts[?(@.name==\"${1}\")].context.cluster}"
 }
 
-alias_context() {
+rename_context() {
   local old_name="${1}"
   local new_name="${2}"
 
@@ -120,11 +118,7 @@ alias_context() {
     exit 1
   fi
 
-  kubectl config set-context "${new_name}" \
-    --cluster="${old_cluster}" \
-    --user="${old_user}" \
-
-  echo "Aliased \"${old_name}\" as \"${new_name}\"." >&2
+  kubectl config rename-context "${old_name}" "${new_name}"
 }
 
 main() {
@@ -139,9 +133,10 @@ main() {
     elif [[ "${1}" == '-h' || "${1}" == '--help' ]]; then
       usage
     elif [[ "${1}" =~ ^-(.*) ]]; then
-      echo "error: unrecognized flag" >&2; usage
+      echo "error: unrecognized flag \"${1}\"" >&2
+      usage
     elif [[ "${1}" =~ (.+)=(.+) ]]; then
-      alias_context "${BASH_REMATCH[2]}" "${BASH_REMATCH[1]}"
+      rename_context "${BASH_REMATCH[2]}" "${BASH_REMATCH[1]}"
     else
       set_context "${1}"
     fi

kubens

@@ -0,0 +1,145 @@
+#!/bin/bash
+#
+# kubenx(1) is a utility to switch between Kubernetes namespaces.
+
+# Copyright 2017 Google Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+[[ -n $DEBUG ]] && set -x
+
+set -eou pipefail
+IFS=$'\n\t'
+
+KUBENS_DIR="${HOME}/.kube/kubens"
+
+usage() {
+  cat <<"EOF"
+USAGE:
+  kubens                    : list the namespaces in the current context
+  kubens <NAME>             : change the active namespace of current context
+  kubens -                  : switch to the previous namespace in this context
+  kubens -h,--help          : show this message
+EOF
+  exit 1
+}
+
+current_namespace() {
+  local cur_ctx=$(current_context)
+  ns="$(kubectl config view -o=jsonpath="{.contexts[?(@.name==\"${cur_ctx}\")].context.namespace}")"
+  if [[ -z "${ns}" ]]; then
+    echo "default"
+  else
+    echo "${ns}"
+  fi
+}
+
+current_context() {
+  kubectl config view -o=jsonpath='{.current-context}'
+}
+
+get_namespaces() {
+  kubectl get namespaces -o=jsonpath='{range .items[*].metadata.name}{@}{"\n"}{end}'
+}
+
+namespace_file() {
+  local ctx="${1}"
+  echo "${KUBENS_DIR}/${ctx}"
+}
+
+read_namespace() {
+  local f="$(namespace_file "${1}")"
+  [[ -f "${f}" ]] && cat "${f}"
+}
+
+save_namespace() {
+  mkdir -p "${KUBENS_DIR}"
+  local f="$(namespace_file "${1}")"
+  local saved="$(read_namespace "${1}")"
+
+  if [[ "${saved}" != "${2}" ]]; then
+    printf %s "${2}" > "${f}"
+  fi
+}
+
+switch_namespace() {
+  local ctx="${1}"
+  kubectl config set-context "${ctx}" --namespace="${2}"
+  echo "Active namespace is \"${2}\".">&2
+}
+
+set_namespace() {
+  local ctx="$(current_context)"
+  local prev="$(current_namespace)"
+
+  if grep -q ^"${1}"\$ <(get_namespaces); then
+    switch_namespace "${ctx}" "${1}"
+
+    if [[ "${prev}" != "${1}" ]]; then
+      save_namespace "${ctx}" "${prev}"
+    fi
+  else
+    echo "error: no namespace exists with name \"${1}\".">&2
+    exit 1
+  fi
+}
+
+list_namespaces() {
+  local cur="$(current_namespace)"
+
+  local yellow=$(tput setaf 3)
+  local darkbg=$(tput setab 0)
+  local normal=$(tput sgr0)
+
+  for c in $(get_namespaces); do
+    if [[ "${c}" = "${cur}" ]]; then
+      echo "${darkbg}${yellow}${c}${normal}"
+    else
+      echo "${c}"
+    fi
+  done
+}
+
+swap_namespace() {
+  local ctx="$(current_context)"
+  local ns="$(read_namespace "${ctx}")"
+  if [[ -z "${ns}" ]]; then
+    echo "error: No previous namespace found for current context." >&2
+    exit 1
+  fi
+  set_namespace "${ns}"
+}
+
+main() {
+  if [[ "$#" -eq 0 ]]; then
+    list_namespaces
+  elif [[ "$#" -eq 1 ]]; then
+    if [[ "${1}" == '-h' || "${1}" == '--help' ]]; then
+      usage
+    elif [[ "${1}" == "-" ]]; then
+      swap_namespace
+    elif [[ "${1}" =~ ^-(.*) ]]; then
+      echo "error: unrecognized flag \"${1}\"" >&2
+      usage
+    elif [[ "${1}" =~ (.+)=(.+) ]]; then
+      alias_context "${BASH_REMATCH[2]}" "${BASH_REMATCH[1]}"
+    else
+      set_namespace "${1}"
+    fi
+  else
+    echo "error: too many flags" >&2
+    usage
+  fi
+}
+
+main "$@"