Nymphia is a DSL to generate a ssh config file more structurally.
You can use full Ruby syntax and useful methods provided by Nymphia.

There is a Vim syntax (nymphia.vim) if you want to edit colorfully in Vim.

Just type gem command,

$ gem install nymphia

$ nymphia --help
nymphia
    -f, --file=FILE                  Your DSL code file
    -o, --output=FILE                Output file (default: stdout)

Following code is a small example.

identity_file :private, '~/.ssh/id_rsa.1'

my_server_port = 4321

host('alice', 'my server on VPS') {
  hostname 'alice.example.com'
  user 'alice'
  port my_server_port
  use_identify_file :private
}

Following ssh config file is generated after the code is compiled.

#
# This config is generated by Nymphia 0.1.2
# @ 2017-12-08T16:34:15+09:00
#

# my server on VPS
Host alice
  Hostname alice.example.com
  User alice
  Port 4321
  IdentityFile ~/.ssh/id_rsa.1

Method identity_file register your identity file with a name. You can use registered identity file by use_identify_file in host block.

Method host generate Host directive. First argument is name of host, Second argument is description of the host. Description is optional.

You can use include_file method to include other Nymphia file like following example. Absolute path and relative path are acceptable as the file path.

We could use load in previous version, but load is obsoleted now.

identity_file :private, '~/.ssh/id_rsa.1'

host('alice', 'my server on VPS') {
  hostname 'alice.example.com'
  user 'alice'
  port 4321
  use_identify_file :private
}

include_file 'other_nymphia_file.rb'

Method proxy is almost same to host, but local_forward method can be used in proxy. Following code is small example of proxy.

identity_file :company_gateway, '~/.ssh/id_rsa.company.gw'

proxy('awsproxy.company.apne1') {
  hostname 'gw.apne1.example.com'
  user 'alice'
  port 19822
  use_identify_file :company_gateway

  # SOCKS proxy
  dynamic_forward 23921

  # ssh tunnels
  local_forward 'mysql-server', {
    'localhost' => 13306,
    'mysql.apne.aws.example.com' => 3306,
  }

  local_forward 'ldap', {
    'localhost' => 10389,
    'ldap.apne.aws.example.com' => 398,
  }
}

Following ssh config file is generated after the code is compiled.

#
# This config is generated by Nymphia 0.1.2
# @ 2017-12-08T16:34:15+09:00
#

Host awsproxy.company.apne1
  Hostname gw.apne1.example.com
  User alice
  Port 19822
  IdentityFile ~/.ssh/id_rsa.company.gw
  DynamicForward 23921
  LocalForward localhost:13306 mysql.apne.aws.example.com:3306
  LocalForward localhost:10389 ldap.apne.aws.example.com:398

Nymphia has group and gateway method to make ssh config more structurally. Following code is small example of grouping.

identity_file :company, '~/.ssh/id_rsa.company'
identity_file :company_gateway, '~/.ssh/id_rsa.company.gw'

gateway('company.gateway') {
  hostname 'gw.example.com'
  user 'alice'
  port 19822
}

group('company.ap-northeast-1') {
  use_gateway 'company.gateway'

  default_params {
    check_host_ip 'no'
    strict_host_key_checking 'no'
    user 'alice'
    port 9822
    use_identify_file :company, :company_gateway
  }

  host('*.apne.aws.example.com')

  host('alice.apne.aws.example.com') {
    hostname '10.16.16.16'
    user 'white_rabbit'
    port 7777
  }
}

Following ssh config file is generated after the code is compiled.

#
# This config is generated by Nymphia 0.1.2
# @ 2017-12-08T16:34:15+09:00
#

Host company.gateway
  Hostname gw.example.com
  User alice
  Port 19822

Host *.apne.aws.example.com
  CheckHostIp no
  StrictHostKeyChecking no
  User alice
  Port 9822
  IdentityFile ~/.ssh/id_rsa.company
  IdentityFile ~/.ssh/id_rsa.company.gw
  ProxyCommand ssh company.gateway -q -W %h:%p

Host alice.apne.aws.example.com
  CheckHostIp no
  StrictHostKeyChecking no
  IdentityFile ~/.ssh/id_rsa.company
  IdentityFile ~/.ssh/id_rsa.company.gw
  ProxyCommand ssh company.gateway -q -W %h:%p
  Hostname 10.16.16.16
  User white_rabbit
  Port 7777

Method gateway is almost same to host, but it can be used in a group by use_gateway method. When write use_gateway in a group, ProxyCommand ssh #{gateway name} -q -W %h:%p directive is added automatically to hosts in the group.

Method default_params defines default parameters of hosts in the group including default_params. In this example, host '*.apne.aws.example.com' has no parameters, but Host *.apne.aws.example.com in result is filled by default parameters. The default parameters can be overide like host 'alice.apne.aws.example.com'.

https://github.com/mozamimy/nymphia.vim

• vim syntax
• Test code
• CI

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

Bug reports and pull requests are welcome on GitHub at https://github.com/mozamimy/nymphia.

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