kubeclient_exec

A simple gem adding exec_pod and cp_pod functionality to Kubeclient.

Note: this is a 1 to 2 day ish project, use at your own risk.

Installation

Add this line to your Gemfile:

gem 'kubeclient_exec'

And then install the gem:

bundle

When you require the gem, the methods exec_pod and cp_pod are automatically included in Kubeclient::Client.

Usage

exec_pod

Execute a command in a Kubernetes Pod container.

Example: simple touch-and-go

client.exec_pod("touch hello-world", "my-pod", "my-namespace", options: { container: 'my-container' })

Example: more advanced

client.exec_pod("/bin/sh", "my-pod", "my-namespace", options: { container: 'my-container' }) do |executor|
  executor.on_stdout do |message|
    puts "STDOUT >> #{message}"
  end

  executor.on_stderr do |message|
    puts "STDERR >> #{message}"
  end
  
  executor.execute('date')
  executor.execute('echo "hello, world!" > test')
  
  EM.add_periodic_timer(0.1) do
    if executor.done?
      executor.stop
    end
  end
end

All code in the block is executed in an EventMachine run block.

cp_pod

Copy a file or directory to/from a Kubernetes Pod container.

Example: copy single file to a container

client.cp_pod("local-file.txt", "/home/local-file-renamed.txt", "my-pod", "my-namespace", options: { container: 'my-container' })

Example: copy directory to a container

client.cp_pod("./my-local-secrets", "/home", "my-pod", "my-namespace", options: { container: 'my-container' })

Example: copy single file from a container

client.cp_pod(".", "/home/local-file-renamed.txt", "my-pod", "my-namespace", options: { container: 'my-container', reverse_direction: true })

Note: copying a single file from a container into a (renamed) single file on your local machine is not yet implemented.

Example: copy single file from a container into variable

result = client.cp_pod(:single_result, "/home/local-file-renamed.txt", "my-pod", "my-namespace", options: { container: 'my-container', reverse_direction: true })

Example: copy directory from a container

client.cp_pod('.', "/home/interesting-results", "my-pod", "my-namespace", options: { container: 'my-container', reverse_direction: true })

Authentication

Both bearer tokens and user certificates should be supported. However, in case user certificates are used, you should pass the certificate and key file locations into options[:tls][:[:cert_chain_file] and options[:tls][:private_key_file] respectively. This is a limitation of EventMachine.

Troubleshooting

Problem: Can I suppress errors?

You can enable the suppress_errors option in the options hash.

Problem: I want to disable TLS peer verification.

You can using options[:tls][:verify_peer] = false

Contributions

Contributions are very much welcome, as the quality of this gem is questionable and I don't have much time to improve it.