Kanrisuru manages remote infrastructure with plain ruby objects. The goal with Kanrisuru is to provide a clean objected oriented wrapper over the most commonly used linux commands, with a clean command interface, and with any usable output, present that as parsed structured data. Kanrisuru doesn't use remote agents to run commands on hosts, nor does the project rely on a large complex set of dependencies.

Getting Started

Kanrisuru requires ruby 2.5.0 at a minimum.

Add this line to your application's Gemfile:

gem 'kanrisuru'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install kanrisuru

Documentation

You can find the official documentation https://kanrisuru.com

Usage Guide

Host

To connect with Kanrisuru to a remote host, provide the login credentials to instantiate a Kanrisuru::Remote::Host instance.

host = Kanrisuru::Remote::Host.new(
  host: 'remote-host-name', 
  username: 'ubuntu', 
  keys: ['~/.ssh/id_rsa']
)

Connect with a Jump / Bastion Host

To connect to a host behind a firewall through a jump / bastion host, pass either an instance of another Kanrisuru::Remote::Host, or a hash of host config values

proxy = Kanrisuru::Remote::Host.new(
  host: 'proxy-host',
  username: 'ubuntu',
  keys: ['~/.ssh/proxy.pem']
)

host = Kanrisuru::Remote::Host.new(
  host: '1.2.3.4', 
  username: 'ubuntu', 
  keys: ['~/.ssh/id_rsa'],
  proxy: proxy
)

host.whoami
'ubuntu'

run a simple echo command on the remote host

host.env['VAR'] = 'world'
result = host.echo('hello $VAR')
result.success?
true

result.to_s
'hello world'

build a custom command

command = Kanrisuru::Command.new('wc')
command << '/home/ubuntu/file1.txt'

host.execute_shell(command)
result = Kanrisuru::Result.new(command) do |cmd|
  items = cmd.to_s.split

  struct = Kanrisuru::Core::File::FileCount.new
  struct.lines = items[0]
  struct.words = items[1]
  struct.characters = items[2]
  struct
end

The Kanrisuru::Result class will only run the parsing block if the command run on the remote host was succeful. The final line will be used to build the result object to be read easily. This instance will also dynamically add getter methods to read the underlying data struct for easier querying capabiltiies.

result.success?
true

result.lines
8

result.characters
150

result.words
85

Cluster

Kanrisuru can manage multiple hosts at the same time with the Kanrisuru::Remote::Cluster.

To instantiate a cluster, add 1 or more hosts:

cluster = Kanrisuru::Remote::Cluster.new({
  host: 'remote-host-1',
  username: 'ubuntu',
  keys: ['~/.ssh/remote_1_id_rsa']
}, {
  host: 'remote-host-2',
  username: 'centos',
  keys: ['~/.ssh/remote_2_id_rsa']
}, {
  host: 'remote-host-3',
  username: 'opensuse',
  keys: ['~/.ssh/remote_3_id_rsa']
})

You can also add a host to a cluster that's already been created

host = Kanrisuru::Remote::Host.new(host: 'remote-host-4', username: 'rhel', keys: ['~/.ssh/remote_4_id_rsa'])

cluster << host 

Run cluster in parallel mode to reduce time waiting on blocking IO

Benchmark.measure do
  cluster.each do |host|
    puts cluster.pwd 
  end
end
# => 0.198980   0.029681   0.228661 (  5.258496)

cluster.parallel = true

Benchmark.measure do
  cluster.each do |host|
    puts cluster.pwd 
  end
end
# => 0.016478   0.007956   0.024434 (  0.120066)

To run across all hosts with a single command, cluster will return a array of result hashes

cluster.whoami
[
  {
    :host => "remote-host-1",
    :result => #<Kanrisuru::Result:0x640 @status=0 @data=#<struct Kanrisuru::Core::Path::UserName user="ubuntu"> @command=sudo -u ubuntu /bin/bash -c "whoami">
  },
  {
    :host => "remote-host-2",
    :result => #<Kanrisuru::Result:0x700 @status=0 @data=#<struct Kanrisuru::Core::Path::UserName user="centos"> @command=sudo -u centos /bin/bash -c "whoami">
  },
  {
    :host => "remote-host-3",
    :result => #<Kanrisuru::Result:0x760 @status=0 @data=#<struct Kanrisuru::Core::Path::UserName user="opensuse"> @command=sudo -u opensuse /bin/bash -c "whoami">
  },
  {
    :host => "remote-host-4",
    :result => #<Kanrisuru::Result:0x820 @status=0 @data=#<struct Kanrisuru::Core::Path::UserName user="rhel"> @command=sudo -u rhel /bin/bash -c "whoami">
  }
]

You can also access each host individually to run a command conditionaly within an iterable block

cluster.each do |host|
  case host.os.release
  when 'ubuntu', 'debian'
    host.apt('update')
  when 'centos', 'redhat', 'fedora'
    host.yum('update')
  when 'opensuse_leap', 'sles'
    host.zypper('update')
  end
end

Development

After checking out the repo, run bin/setup to install dependencies.

To test kanrisuru across various linux distros, update your local /etc/hosts file to create an alias to the local virtual machine with that distro type. You can also set the host alias to the localhost machine.

To select which hosts to run rspec across, prepend the command line or export the variable while running rspec.

HOSTS=ubuntu,debian,centos rspec

This will run tests on the ubuntu, debian and centos instances.

Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/avamia/kanrisuru. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

License

The gem is available as open source under the terms of the MIT License.

Code of Conduct

Everyone interacting in the Kanrisuru project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.