Plugins

nib plugins

nib

• nib is a convenience wrapper for docker-compose
• originally designed with Ruby/Rails developers in mind but has features that would be helpful for any developer

Plugin Architecture

Background

• Requested features did not necessarily fit in the core nib code base
• Some features might be very specific to a Technekes workflow

link

Discovery Design

• Requirements: little/no configuration, easy to install and implement, core commands overridable
• Approach borrowed from minitest
• Use RubyGems to search the file system for potential plugins
• Allow the plugin to "self select"

link

Plugin Implementation

There are three requirements for a nib plugin:

1. A Ruby gem that relies on gli for defining it's CLI interface following the naming convention bin/nib-*
2. It puts a file on the LOAD_PATH that ends with _plugin.rb following the naming convention ./lib/nib_*_plugin.rb
3. Implements .applies?, which allows the plugin to "self-select" (ie. was the command was run in what appears to be an applicable project)

Plugin Example

As an example let's define a plugin for nib that caters to Ruby developers.

# ./bin/nib-echo

#!/usr/bin/env ruby

desc 'Say hello nib-echo'
arg :text, %i(multiple)
command :echo do |c|
  c.action do |_global_options, _options, args|
    puts args.join(' ')
  end
end

# ./lib/nib_echo_plugin.rb

module Nib
  module Echo
    def self.applies?
      # echo always applies!
      true
    end
  end
end

# ./nib-echo.gemspec

lib = File.expand_path('../lib', __FILE__)
$LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
...

If nib-echo has been installed and a nib command is run it will append gli commands from bin/nib-echo.

docs

Existing Plugins

nib-crypt

Opinionated secrets management.

• Create an encryption key for a project (directory) and push it to an S3 bucket (requires environment variable)
• Pull an encryption key from an S3 bucket for an existing project
• Convenience wrappers around encryption and decryption (uses openssl and before mentioned key)

COMMANDS
    ...
    crypt-init  - Initialize a project (create or pull secret key)
    ...
    decrypt     - Decrypt a file
    encrypt     - Encrypt a file
    ...

link

nib-heroku

Integrates commands with Heroku

• Uses the directory name to infer a Heroku application name (following Technekes convention)
• Accepts an environment flag
• If non-development environment flag is specified will shell out to Heroku CLI to integrate a shell session or logs

COMMANDS
    ...
    logs        - Access logs for the speified service or Heroku application
    ...
    shell       - Start a shell session in a one-off service container
    ...

link

Live Demo

Let's create nib-echo!

# fire up a Ruby container
docker run --rm -it -v $PWD:$PWD -w $PWD ruby:alpine ash

# scaffold a new gem
bundle gem --test=none --mit --no-coc --bin nib-echo
cd nib-echo

# update nib-echo.gemspec (simplified version)
echo "
\$LOAD_PATH.unshift(File.expand_path('../lib', __FILE__))

Gem::Specification.new do |spec|
  spec.name    = 'nib-echo'
  spec.version = '0.1.0'
  spec.summary = 'nib-echo'
  spec.authors = ['John']

  spec.files         = Dir['lib/**/*.rb']
  spec.require_paths = ['lib']
  spec.bindir        = 'bin'
  spec.executables   = ['nib-echo']

  spec.add_runtime_dependency 'nib', '>= 2.0'

  spec.add_development_dependency 'bundler', '~> 1.16'
  spec.add_development_dependency 'rake', '~> 10.0'
end
" > nib-echo.gemspec

# nib currently expect bin/nib-echo but bundler creates exe/nib-echo
rm -rf exe

# edit the executable
echo "
#!/usr/bin/env ruby

desc 'Say hello nib-echo'
arg :text, %i(multiple)
command :echo do |c|
  c.action do |_global_options, _options, args|
    puts args.join(' ')
  end
end
" > bin/nib-echo

# create plugin detection file
echo "
module Nib
  module Echo
    def self.applies?
      # echo always applies!
      true
    end
  end
end
" > lib/nib_echo_plugin.rb

# build the gem
rake build

# exit the docker container
exit

# install the gem
gem install nib-echo/pkg/nib-echo-0.1.0.gem

# does it work?! 🤞
nib help
nib echo hello world