Useful Tools for Kubernetes

K9s

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.

derailed/k9s

Installation

Via Homebrew or LinuxBrew for macOS and Linux

brew install derailed/k9s/k9s

PreFlight Checks (.bash_profile)

• 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.

# Kubectl edit command will use this env var.
export EDITOR=my_fav_editor
# Should your editor deals with streamed vs on disk files differently, also set...
export K9S_EDITOR=my_fav_editor

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

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

Kubectx + Kubens

ahmetb/kubectx

• kubectx: helps you switch between clusters back and forth:

• kubens: helps you switch between Kubernetes namespaces smoothly:

Installation

brew install kubectx

Kubectx

• Usage

USAGE:
  kubectx                   : list the contexts
  kubectx <NAME>            : switch to context <NAME>
  kubectx -                 : switch to the previous context
  kubectx -c, --current     : show the current context name
  kubectx <NEW_NAME>=<NAME> : rename context <NAME> to <NEW_NAME>
  kubectx <NEW_NAME>=.      : rename current-context to <NEW_NAME>
  kubectx -d <NAME>         : delete context <NAME> ('.' for current-context)
                              (this command won't delete the user/cluster entry
                              that is used by the context)
  kubectx -u, --unset       : unset the current context

• Examples

$ kubectx minikube
Switched to context "minikube".

$ kubectx -
Switched to context "oregon".

$ kubectx -
Switched to context "minikube".

$ kubectx dublin=gke_ahmetb_europe-west1-b_dublin
Context "dublin" set.
Aliased "gke_ahmetb_europe-west1-b_dublin" as "dublin".

Kubens

• Usage

USAGE:
  kubens                    : list the namespaces
  kubens <NAME>             : change the active namespace
  kubens -                  : switch to the previous namespace
  kubens -c, --current      : show the current namespace

• Examples

$ kubens kube-system
Context "test" set.
Active namespace is "kube-system".

$ kubens -
Context "test" set.
Active namespace is "default".

kube-ps1

A script that lets you add the current Kubernetes context and namespace configured on kubectl to your Bash/Zsh prompt strings

jonmosco/kube-ps1

Installation

$ brew update
$ brew install kube-ps1

Popeye

Popeye is a utility that scans live Kubernetes cluster and reports potential issues with deployed resources and configurations. https://github.com/derailed/popeye

Installation

brew install derailed/popeye/popeye

Command Line

# Dump version info
popeye version
# Popeye a cluster using your current kubeconfig environment.
popeye
# Popeye uses a spinach config file of course! aka spinachyaml!
popeye -f spinach.yml
# Popeye a cluster using a kubeconfig context.
popeye --context olive
# Stuck?
popeye help

Stern

Stern allows you to tail multiple pods on Kubernetes and multiple containers within the pod. Each result is color coded for quicker debugging.

wercker/stern

Installation

brew install stern

Usage

stern pod-query [flags]

cli flags

Examples

Tail the gateway container running inside of the envvars pod on staging

stern envvars --context staging --container gateway

Tail the staging namespace excluding logs from istio-proxy container

stern -n staging --exclude-container istio-proxy .

Show auth activity from 15min ago with timestamps

stern auth -t --since 15m

Follow the development of some-new-feature in minikube

stern some-new-feature --context minikube

View pods from another namespace

stern kubernetes-dashboard --namespace kube-system

Tail the pods filtered by run=nginx label selector across all namespaces

stern --all-namespaces -l run=nginx

Follow the frontend pods in canary release

stern frontend --selector release=canary

Pipe the log message to jq:

stern backend -o json | jq .

Only output the log message itself:

stern backend -o raw

Output using a custom template:

stern --template '{{.Message}} ({{.Namespace}}/{{.PodName}}/{{.ContainerName}})' backend

Output using a custom template with stern-provided colors:

stern --template '{{.Message}} ({{.Namespace}}/{{color .PodColor .PodName}}/{{color .ContainerColor .C

Lens

Lens is the only IDE you’ll ever need to take control of your Kubernetes clusters. It is a standalone application for MacOS, Windows and Linux operating systems. It is open source and free.

lensapp/lens