OptionScrapper!
Is a wrapper for the OptionsParser (optparse) gem which makes using subcommand like cli easier to define. Note, all the options configuration is passed directly to optparse; so anything it supports, this will support;
require 'optionscrapper'
require 'pp'
@options = {
:config => '../config/openstack.yaml',
:flavor => '2cores-4096mem-10gb',
:image => 'centos-base-6.5-min-stable',
:user_data => '../config/user_data.erb',
:keypair => 'default',
:networks => [],
:security_group => [ 'default' ],
:verbose => true,
:force => false
}
begin
def parser
@parser ||= OptionScrapper::new do |o|
o.on( '-S stack', '--stack NAME', 'the name of the openstack you wish to connect' ) { |x| @options[:stack] = x }
o.on( '-c CONFIG', '--config CONFIG', 'the configuration file to read credentials' ) { |x| @options[:config] = x }
o.on( nil, '--dry-run', 'perform a dry run' ) { @options[:dry_run] = true }
o.on( '-v', '--verbose', 'switch on verbose mode' ) { @options[:verbose] = true }
o.command :launch, 'launch a instance in to openstack cluster' do
o.command_alias :ln
o.on( '-H HOSTNAME', '--hostname HOSTNAME', 'the hostname of instance you are creating' ) { |x| @options[:hostname] = x }
o.on( '-i IMAGE', '--image IMAGE', 'the image you wish to boot from' ) { |x| @options[:image] = x }
o.on( '-f FLAVOR', '--flavor FLAVOR', 'the flavor the instance should work from' ) { |x| @options[:flavor] = x }
o.on( '-k KEYPAIR', '--keypair KEYPAIR', 'the keypair the instance should use' ) { |x| @options[:keypair] = x }
o.on( '-n NETWORK', '--network NETWORK', 'the network the instance should be connected' ) { |x| @options[:networks] << x }
o.on( '-s SECURITY', '--secgroups SECURITY', 'the security group assigned to the instance' ) { |x| @options[:security_group] << x }
o.on( '-u USER_DATA', '--user-data USER_DATA', 'the user data template' ) { |x| @options[:user_data] = x }
o.on( nil, '--hypervisor HOST', 'the compute node you want the instance to run' ) { |x| @options[:availability_zone] = x }
o.on( '-e', '--error', 'cause an error' ) { o.usage }
o.on_command { @options[:action] = :launch }
end
o.command :destroy, 'destroy and delete an instance in openstack' do
o.command_alias :des
o.on( '-H HOSTNAME', '--hostname HOSTNAME', 'the hostname of instance you are creating' ) { |x| @options[:hostname] = x }
o.on_command { @options[:action] = :destroy }
end
o.command :snapshot, 'snapshot a instance within openstack' do
o.command_alias :sp
o.on( '-H HOSTNAME', '--hostname HOSTNAME', 'the hostname of the instance being snapshot' ) { |x| @options[:hostname] = x }
o.on( '-s NAME', '--snapshot NAME', 'the name of the snapshot you are creating' ) { |x| @options[:snapshot] = x }
o.on( nil, '--wait', 'wait on the snapshot to complete' ) { |x| @options[:wait] = true }
o.on( '-f', '--force', 'if the snapshot image exists, delete it' ) { |x| @options[:force] = true }
o.on_command { @options[:action] = :snapshot }
end
end
end
Will produce the following usage menu. Note, the -h|--help is injected in the default parser by default
[jest@starfury tests]$ ./test.rb --help
Usage: test.rb [options]
-h, --help display this usage menu
-S, --stack NAME the name of the openstack you wish to connect
-c, --config CONFIG the configuration file to read credentials
--dry-run perform a dry run
-v, --verbose switch on verbose mode
commands : -------------------------------------------------------------
launch (ln) launch a instance in to openstack cluster
destroy (des) destroy and delete an instance in openstack
snapshot (sp) snapshot a instance within openstack
------------------------------------------------------------------------
launch : description: launch a instance in to openstack cluster
------------------------------------------------------------------------
-H, --hostname HOSTNAME the hostname of instance you are creating
-i, --image IMAGE the image you wish to boot from
-f, --flavor FLAVOR the flavor the instance should work from
-k, --keypair KEYPAIR the keypair the instance should use
-n, --network NETWORK the network the instance should be connected
-s, --secgroups SECURITY the security group assigned to the instance
-u, --user-data USER_DATA the user data template
--hypervisor HOST the compute node you want the instance to run
-e, --error cause an error
destroy : description: destroy and delete an instance in openstack
------------------------------------------------------------------------
-H, --hostname HOSTNAME the hostname of instance you are creating
snapshot : description: snapshot a instance within openstack
------------------------------------------------------------------------
-H, --hostname HOSTNAME the hostname of the instance being snapshot
-s, --snapshot NAME the name of the snapshot you are creating
--wait wait on the snapshot to complete
-f, --force if the snapshot image exists, delete it
Or to print just the menu of the subcommand
[jest@starfury tests]$ ./test.rb ln --help
launch : description: launch a instance in to openstack cluster
------------------------------------------------------------------------
-H, --hostname HOSTNAME the hostname of instance you are creating
-i, --image IMAGE the image you wish to boot from
-f, --flavor FLAVOR the flavor the instance should work from
-k, --keypair KEYPAIR the keypair the instance should use
-n, --network NETWORK the network the instance should be connected
-s, --secgroups SECURITY the security group assigned to the instance
-u, --user-data USER_DATA the user data template
--hypervisor HOST the compute node you want the instance to run
-e, --error cause an error
Mixing Options
The order of the options is not enforced, thus global options can be placed anywhere on the command line. If however, there is a conflict, i.e. the subcommand has the same flag/s as a global option, the subcommand takes precedence.
Contributing
- Fork it
- Create your feature branch (git checkout -b my-new-feature)
- Commit your changes (git commit -am 'Add some feature')
- Push to the branch (git push origin my-new-feature)
- Create new Pull Request
- If applicable, update the README.md