kubectl ssh-proxy

Proxy OpenSSH client tools through Kubernetes pod

flowchart LR
    subgraph client
        Start[kubectl ssh-proxy]
    end
    subgraph k8s
        kube-api-server <-->|exec| pod(ssh-proxy-pod)
        pod <--> nc
        nc <-->|ssh| End[targetHost]
    end
    Start[kubectl ssh-proxy] <-->|HTTPS| kube-api-server

Prerequisites

kubectl
krew

Installation

kubectl krew install --manifest-url https://raw.githubusercontent.com/infinite-turtles/kubectl-ssh-proxy/main/deploy/krew/plugin.yaml

Usage

kubectl ssh-proxy [flags] ssh|scp|sftp [flags] [arguments]

# ssh login to remote system
kubectl ssh-proxy ssh user@hostname

# scp secure file copy
kubectl ssh-proxy scp localpath [user@]host:[path]

# sftp secure file transfer
kubectl ssh-proxy sftp [user@]host[:path]

Use with K9s Plugin

The K9s project has a plugin feature that allows users to configure key-mappings to execute commands on your system.

Demo:

Configure K9s:

The following implements a plugin that uses kubectl-ssh-proxy to easily SSH into any node directly from K9s. First, create or modify the file $XDG_CONFIG_HOME/k9s/plugin.yml. If XDG_CONFIG_HOME is not used in your terminal, simply define it to any directory.

Example:

export XDG_CONFIG_HOME=$HOME/.config

Older versions of k9s might have config in ~/.k9s/ instead.

Next create the $XDG_CONFIG_HOME/k9s/plugin.yml file:

# $XDG_CONFIG_HOME/k9s/plugin.yml
plugin:
  # Defines a plugin to provide a `ctrl-n` shortcut to tail the logs while in node view.
  ksshNode:
    # Define a mnemonic to invoke the plugin
    shortCut: Ctrl-N
    # What will be shown on the K9s menu
    description: Node SSH
    # Collections of views that support this shortcut. (You can use `all`)
    scopes:
    - no
    # The command to run upon invocation. Can use Krew plugins here too!
    command: kubectl-ssh-proxy
    # Whether or not to run the command in background mode
    background: false
    # Defines the command arguments
    args:
    - ssh
    - ec2-user@$NAME

  # Defines a plugin to provide a `ctrl-n` shortcut to tail the logs while in pod view.
  ksshPod:
    # Define a mnemonic to invoke the plugin
    shortCut: Ctrl-N
    # What will be shown on the K9s menu
    description: Node SSH
    # Collections of views that support this shortcut. (You can use `all`)
    scopes:
    - po
    # The command to run upon invocation. Can use Krew plugins here too!
    command: kubectl-ssh-proxy
    # Whether or not to run the command in background mode
    background: false
    # Defines the command arguments
    args:
    - ssh
    - ec2-user@$COL-NODE

After this you should be ready to to start up K9s. Then simply select a node, press ctrl-n, and viola! kubectl-ssh-proxy is used to SSH into the selected node.