/k9s

šŸ¶ Kubernetes CLI To Manage Your Clusters In Style!

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K9s - Kubernetes CLI To Manage Your Clusters In Style!

K9s provides a terminal UI to interact with your Kubernetes clusters. The aim of this project is to make it easier to navigate, observe and manage your applications in the wild. K9s continually watches Kubernetes for changes and offers subsequent commands to interact with your observed resources.

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Documentation

Please refer to our K9s documentation site for installation, usage, customization and tips.

Slack Channel

Wanna discuss K9s features with your fellow K9sers or simply show your support for this tool?

Installation

K9s is available on Linux, macOS and Windows platforms.

  • Binaries for Linux, Windows and Mac are available as tarballs in the release page.

  • Via Homebrew or LinuxBrew for macOS and Linux

    brew install derailed/k9s/k9s

  • Via MacPorts

    sudo port install k9s

  • On Arch Linux

    pacman -S k9s

  • Via Scoop for Windows

    scoop install k9s

  • Building from source K9s was built using go 1.13 or above. In order to build K9 from source you must:

    1. Clone the repo

    2. Add the following command in your go.mod file

      replace (
  github.com/derailed/k9s => MY_K9S_CLONED_GIT_REPO
)

    3. Build and run the executable

      go run main.go

PreFlight Checks

  • K9s uses 256 colors terminal mode. On `Nix system make sure TERM is set accordingly.

    export TERM=xterm-256color

  • In order to issue manifest edit commands make sure your EDITOR env is set.

       export EDITOR=my_fav_editor_here!

The Command Line

# List all available CLI options
k9s help
# To get info about K9s runtime (logs, configs, etc..)
k9s info
# To run K9s in a given namespace
k9s -n mycoolns
# Start K9s in an existing KubeConfig context
k9s --context coolCtx
# Start K9s in readonly mode - with all modification commands disabled
k9s --readonly

Logs

Given the nature of the ui k9s does produce logs to a specific location. To view the logs and turn on debug mode, use the following commands:

k9s info
# Will produces something like this
#  ____  __.________
# |    |/ _/   __   \______
# |      < \____    /  ___/
# |    |  \   /    /\___ \
# |____|__ \ /____//____  >
#         \/            \/
#
# Configuration:   /Users/fernand/.k9s/config.yml
# Logs:            /var/folders/8c/hh6rqbgs5nx_c_8k9_17ghfh0000gn/T/k9s-fernand.log
# Screen Dumps:    /var/folders/8c/hh6rqbgs5nx_c_8k9_17ghfh0000gn/T/k9s-screens-fernand

# To view k9s logs
tail -f /var/folders/8c/hh6rqbgs5nx_c_8k9_17ghfh0000gn/T/k9s-fernand.log

# Start K9s in debug mode
k9s -l debug

Key Bindings

K9s uses aliases to navigate most K8s resources.

Action Command Comment
Show active keyboard mnemonics and help ?
Show all available resource alias ctrl-a
To bail out of K9s :q, ctrl-c
View a Kubernetes resource using singular/plural or shortname :poāŽ accepts singular, plural, shortname or alias ie pod or pods
View a Kubernetes resource in a given namespace :alias namespaceāŽ
Filter out a resource view given a filter /filterāŽ
Filter resource view by labels /-l label-selectorāŽ
Fuzzy find a resource given a filter /-f filterāŽ
Bails out of view/command/filter mode <esc>
Key mapping to describe, view, edit, view logs,... d,v, e, l,...
To view and switch to another Kubernetes context :ctxāŽ
To view and switch to another Kubernetes context :ctx context-nameāŽ
To view and switch to another Kubernetes namespace :nsāŽ
To view all saved resources :screendump or sdāŽ
To delete a resource (TAB and ENTER to confirm) ctrl-d
To kill a resource (no confirmation dialog!) ctrl-k
Launch pulses view :pulses or puāŽ
Launch XRay view :xray RESOURCE [NAMESPACE]āŽ RESOURCE can be one of po, svc, dp, rs, sts, ds, NAMESPACE is optional

Screenshots

  1. Pods
  2. Logs
  3. Deployments

Headers description

Pods view

Header Description
NAME Pod name
IMAGE Image used
READY Is pod ready ?
STATE Pod state
INIT Is an init pod ?
RS Restart count
PROBES(L:R) Liveness and Readiness probes
CPU CPU used (millicores)
MEM Memory used (Mb)
%CPU/R % ratio of CPU used/requested
%MEM/R % ratio of MEM used/requested
%CPU/L % ratio of CPU used/limit
%MEM/L % ratio of MEM used/limit
PORTS Ports exposed
AGE Pod age

Demo Videos/Recordings

K9s Configuration

K9s keeps its configurations in a .k9s directory in your home directory $HOME/.k9s/config.yml.

NOTE: This is still in flux and will change while in pre-release stage!

# config.yml
k9s:
  # Represents ui poll intervals.
  refreshRate: 2
  # Indicates whether modification commands like delete/kill/edit are disabled. Default is false
  readOnly: false
  # Logs configuration
  logger:
    # Defines the number of lines to return. Default 100
    tail: 200
    # Defines the total number of log lines to allow in the view. Default 1000
    buffer: 500
    # Represents how far to go back in the log timeline in seconds. Default is 5min
    sinceSeconds: 300
  # Indicates the current kube context. Defaults to current context
  currentContext: minikube
  # Indicates the current kube cluster. Defaults to current context cluster
  currentCluster: minikube
  # Persists per cluster preferences for favorite namespaces and view.
  clusters:
    cooln:
      namespace:
        active: coolio
        favorites:
        - cassandra
        - default
      view:
        active: po
    minikube:
      namespace:
        active: all
        favorites:
        - all
        - kube-system
        - default
      view:
        active: dp

Command Aliases

In K9s, you can define your very own command aliases (shortnames) to access your resources. In your $HOME/.k9s define a file called alias.yml. A K9s alias defines pairs of alias:gvr. A gvr (Group/Version/Resource) represents a fully qualified Kubernetes resource identifier. Here is an example of an alias file:

# $HOME/.k9s/alias.yml
alias:
  pp: v1/pods
  crb: rbac.authorization.k8s.io/v1/clusterrolebindings

Using this alias file, you can now type pp/crb to list pods or clusterrolebindings respectively.

HotKey Support

Entering the command mode and typing a resource name or alias, could be cumbersome for navigating thru often used resources. We're introducing hotkeys that allows a user to define their own hotkeys to activate their favorite resource views. In order to enable hotkeys please follow these steps:

  1. Create a file named $HOME/.k9s/hotkey.yml

  2. Add the following to your hotkey.yml. You can use resource name/short name to specify a command ie same as typing it while in command mode.

    # $HOME/.k9s/hotkey.yml
hotKey:
  # Hitting Shift-0 navigates to your pod view
  shift-0:
    shortCut:    Shift-0
    description: Viewing pods
    command:     pods
  # Hitting Shift-1 navigates to your deployments
  shift-1:
    shortCut:    Shift-1
    description: View deployments
    command:     dp
  # Hitting Shift-2 navigates to your xray deployments
  shift-2:
    shortCut:    Shift-2
    description: Xray Deployments
    command:     xray deploy

Not feeling so hot? Your custom hotkeys will be listed in the help view ?. Also your hotkey file will be automatically reloaded so you can readily use your hotkeys as you define them.

You can choose any keyboard shotcuts that make sense to you, provided they are not part of the standard K9s shortcuts list.

NOTE: This feature/configuration might change in future releases!

Plugins

K9s allows you to extend your command line and tooling by defining your very own cluster commands via plugins. K9s will look at $HOME/.k9s/plugin.yml to locate all available plugins. A plugin is defined as follows:

  • Shortcut option represents the key combination a user would type to activate the plugin
  • Description will be printed next to the shortcut in the k9s menu
  • Scopes defines a collection of resources names/shortnames for the views associated with the plugin. You can specify all to provide this shortcut for all views.
  • Command represents adhoc commands the plugin runs upon activation
  • Background specifies whether or not the command runs in the background
  • Args specifies the various arguments that should apply to the command above

K9s does provide additional environment variables for you to customize your plugins arguments. Currently, the available environment variables are as follows:

  • $NAMESPACE -- the selected resource namespace
  • $NAME -- the selected resource name
  • $CONTAINER -- the current container if applicable
  • $FILTER -- the current filter if any
  • $KUBECONFIG -- the KubeConfig location.
  • $CLUSTER the active cluster name
  • $CONTEXT the active context name
  • $USER the active user
  • $GROUPS the active groups
  • $POD while in a container view
  • $COL-<RESOURCE_COLUMN_NAME> use a given column name for a viewed resource. Must be prefixed by COL-!

Example

This defines a plugin for viewing logs on a selected pod using ctrl-l for shorcut.

# $HOME/.k9s/plugin.yml
plugin:
  # Defines a plugin to provide a `ctrl-l` shorcut to tail the logs while in pod view.
  fred:
    shortCut: Ctrl-L
    description: Pod logs
    scopes:
    - pods
    command: kubectl
    background: false
    args:
    - logs
    - -f
    - $NAME
    - -n
    - $NAMESPACE
    - --context
    - $CONTEXT

NOTE: This is an experimental feature! Options and layout may change in future K9s releases as this feature solidifies.

Benchmark Your Applications

K9s integrates Hey from the brilliant and super talented Jaana Dogan. Hey is a CLI tool to benchmark HTTP endpoints similar to AB bench. This preliminary feature currently supports benchmarking port-forwards and services (Read the paint on this is way fresh!).

To setup a port-forward, you will need to navigate to the PodView, select a pod and a container that exposes a given port. Using SHIFT-F a dialog comes up to allow you to specify a local port to forward. Once acknowledged, you can navigate to the PortForward view (alias pf) listing out your active port-forwards. Selecting a port-forward and using CTRL-B will run a benchmark on that HTTP endpoint. To view the results of your benchmark runs, go to the Benchmarks view (alias be). You should now be able to select a benchmark and view the run stats details by pressing <ENTER>. NOTE: Port-forwards only last for the duration of the K9s session and will be terminated upon exit.

Initially, the benchmarks will run with the following defaults:

  • Concurrency Level: 1
  • Number of Requests: 200
  • HTTP Verb: GET
  • Path: /

The PortForward view is backed by a new K9s config file namely: $HOME/.k9s/bench-mycluster.yml. Each cluster you connect to will have its own bench config file. Changes to this file should automatically update the PortForward view to indicate how you want to run your benchmarks.

Here is a sample benchmarks.yml configuration. Please keep in mind this file will likely change in subsequent releases!

# This file resides in $HOME/.k9s/bench-mycluster.yml
benchmarks:
  # Indicates the default concurrency and number of requests setting if a container or service rule does not match.
  defaults:
    # One concurrent connection
    concurrency: 1
    # Number of requests that will be sent to an endpoint
    requests: 500
  containers:
    # Containers section allows you to configure your http container's endpoints and benchmarking settings.
    # NOTE: the container ID syntax uses namespace/pod-name:container-name
    default/nginx:nginx:
      # Benchmark a container named nginx using POST HTTP verb using http://localhost:port/bozo URL and headers.
      concurrency: 1
      requests: 10000
      http:
        path: /bozo
        method: POST
        body:
          {"fred":"blee"}
        header:
          Accept:
            - text/html
          Content-Type:
            - application/json
  services:
    # Similary you can Benchmark an HTTP service exposed either via nodeport, loadbalancer types.
    # Service ID is ns/svc-name
    default/nginx:
      # Set the concurrency level
      concurrency: 5
      # Number of requests to be sent
      requests: 500
      http:
        method: GET
        # This setting will depend on whether service is nodeport or loadbalancer. Nodeport may require vendor port tuneling setting.
        # Set this to a node if nodeport or LB if applicable. IP or dns name.
        host: A.B.C.D
        path: /bumblebeetuna
      auth:
        user: jean-baptiste-emmanuel
        password: Zorg!

K9s RBAC FU

On RBAC enabled clusters, you would need to give your users/groups capabilities so that they can use K9s to explore their Kubernetes cluster. K9s needs minimally read privileges at both the cluster and namespace level to display resources and metrics.

These rules below are just suggestions. You will need to customize them based on your environment policies. If you need to edit/delete resources extra Fu will be necessary.

NOTE! Cluster/Namespace access may change in the future as K9s evolves. NOTE! We expect K9s to keep running even in atrophied clusters/namespaces. Please file issues if this is not the case!

Cluster RBAC scope

---
# K9s Reader ClusterRole
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: k9s
rules:
  # Grants RO access to cluster resources node and namespace
  - apiGroups: [""]
    resources: ["nodes", "namespaces"]
    verbs: ["get", "list", "watch"]
  # Grants RO access to RBAC resources
  - apiGroups: ["rbac.authorization.k8s.io"]
    resources: ["clusterroles", "roles", "clusterrolebindings", "rolebindings"]
    verbs: ["get", "list", "watch"]
  # Grants RO access to CRD resources
  - apiGroups: ["apiextensions.k8s.io"]
    resources: ["customresourcedefinitions"]
    verbs: ["get", "list", "watch"]
  # Grants RO access to metric server (if present)
  - apiGroups: ["metrics.k8s.io"]
    resources: ["nodes", "pods"]
    verbs: ["get", "list", "watch"]

---
# Sample K9s user ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: k9s
subjects:
  - kind: User
    name: fernand
    apiGroup: rbac.authorization.k8s.io
roleRef:
  kind: ClusterRole
  name: k9s
  apiGroup: rbac.authorization.k8s.io

Namespace RBAC scope

If your users are constrained to certain namespaces, K9s will need to following role to enable read access to namespaced resources.

---
# K9s Reader Role (default namespace)
kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: k9s
  namespace: default
rules:
  # Grants RO access to most namespaced resources
  - apiGroups: ["", "apps", "autoscaling", "batch", "extensions"]
    resources: ["*"]
    verbs: ["get", "list", "watch"]
  # Grants RO access to metric server
  - apiGroups: ["metrics.k8s.io"]
    resources: ["pods", "nodes"]
    verbs:
      - get
      - list
      - watch

---
# Sample K9s user RoleBinding
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: k9s
  namespace: default
subjects:
  - kind: User
    name: fernand
    apiGroup: rbac.authorization.k8s.io
roleRef:
  kind: Role
  name: k9s
  apiGroup: rbac.authorization.k8s.io

Skins

Example: Dracula Skin ;)

You can style K9s based on your own sense of look and style. Skins are YAML files, that enable a user to change the K9s presentation layer. K9s skins are loaded from $HOME/.k9s/skin.yml. If a skin file is detected then the skin would be loaded if not the current stock skin remains in effect.

You can also change K9s skins based on the cluster you are connecting too. In this case, you can specify the skin file name as $HOME/.k9s/mycluster_skin.yml Below is a sample skin file, more skins are available in the skins directory in this repo, just simply copy any of these in your user's home dir as skin.yml.

Colors can be defined by name or uing an hex representation. Of recent, we've added a color named default to indicate a transparent background color to preserve your terminal background color settings if so desired.

NOTE: This is very much an experimental feature at this time, more will be added/modified if this feature has legs so thread accordingly!

# Skin InTheNavy...
k9s:
  # General K9s styles
  body:
    fgColor: dodgerblue
    bgColor: '#ffffff'
    logoColor: '#0000ff'
  # ClusterInfoView styles.
  info:
    fgColor: lightskyblue
    sectionColor: steelblue
  frame:
    # Borders styles.
    border:
      fgColor: dodgerblue
      focusColor: aliceblue
    # MenuView attributes and styles.
    menu:
      fgColor: darkblue
      keyColor: cornflowerblue
      # Used for favorite namespaces
      numKeyColor: cadetblue
    # CrumbView attributes for history navigation.
    crumbs:
      fgColor: white
      bgColor: steelblue
      activeColor: skyblue
    # Resource status and update styles
    status:
      newColor: '#00ff00'
      modifyColor: powderblue
      addColor: lightskyblue
      errorColor: indianred
      highlightcolor: royalblue
      killColor: slategray
      completedColor: gray
    # Border title styles.
    title:
      fgColor: aqua
      bgColor: white
      highlightColor: skyblue
      counterColor: slateblue
      filterColor: slategray
  views:
    # TableView attributes.
    table:
      fgColor: blue
      bgColor: darkblue
      cursorColor: aqua
      # Header row styles.
      header:
        fgColor: white
        bgColor: darkblue
        sorterColor: orange
    # YAML info styles.
    yaml:
      keyColor: steelblue
      colonColor: blue
      valueColor: royalblue
    # Logs styles.
    logs:
      fgColor: white
      bgColor: black

Here is a list of all available color names.

Color Names
black maroon green olive navy
purple teal silver gray red
lime yellow blue fuchsia aqua
white aliceblue antiquewhite aquamarine azure
beige bisque blanchedalmond blueviolet brown
burlywood cadetblue chartreuse chocolate coral
cornflowerblue cornsilk crimson darkblue darkcyan
darkgoldenrod darkgray darkgreen darkkhaki darkmagenta
darkolivegreen darkorange darkorchid darkred darksalmon
darkseagreen darkslateblue darkslategray darkturquoise darkviolet
deeppink deepskyblue dimgray dodgerblue firebrick
floralwhite forestgreen gainsboro ghostwhite gold
goldenrod greenyellow honeydew hotpink indianred
indigo ivory khaki lavender lavenderblush
lawngreen lemonchiffon lightblue lightcoral lightcyan
lightgoldenrodyellow lightgray lightgreen lightpink lightsalmon
lightseagreen lightskyblue lightslategray lightsteelblue lightyellow
limegreen linen mediumaquamarine mediumblue mediumorchid
mediumpurple mediumseagreen mediumslateblue mediumspringgreen mediumturquoise
mediumvioletred midnightblue mintcream mistyrose moccasin
navajowhite oldlace olivedrab orange orangered
orchid palegoldenrod palegreen paleturquoise palevioletred
papayawhip peachpuff peru pink plum
powderblue rebeccapurple rosybrown royalblue saddlebrown
salmon sandybrown seagreen seashell sienna
skyblue slateblue slategray snow springgreen
steelblue tan thistle tomato turquoise
violet wheat whitesmoke yellowgreen grey
dimgrey darkgrey darkslategrey lightgrey lightslategrey
slategrey

Known Issues

This is still work in progress! If something is broken or there's a feature that you want, please open a PR or file a ticket.

K9s will most likely blow up if...

  1. You're running older versions of Kubernetes. K9s works best on Kubernetes latest.
  2. You don't have enough RBAC fu to manage your cluster.

ATTA Girls/Boys!

K9s sits on top of many open source projects and libraries. Our sincere appreciations to all the OSS contributors that work nights and weekends to make this project a reality!

Meet The Core Team!

 Ā© 2020 Imhotep Software LLC. All materials licensed under Apache v2.0