Class Net::SSH::Session
In: lib/net/ssh/session.rb
Parent: Object

Encapsulates a single session (connection) to a server via SSH.

Methods

close   loop   method_missing   new   open?   open_channel  

Attributes

connection  [R]  The underlying connection
host  [R]  The name of the host that this session is connected to.
options  [R]  The hash of options that were used to establish this session.
registry  [R]  The dependency-injection registry used by this session.

Public Class methods

Create a new SSH session. This method polymorphically accepts a variable number of parameters, as follows:

  • 1 parameter: must be the hostname to connect to.
  • 2 parameters: must be the hostname, and either the port (as an integer) or the username to connect as.
  • 3 parameters: must be the hostname, and either the port (as an integer) and username, or the username and the password.
  • 4 parameters: must be the hostname, port, username, and password.

Any scenario above that omits the username assumes that the USER environment variable is set to the user’s name. Any scenario above that omits the password assumes that the user will log in without a password (ie, using a public key). Any scenario above that omits the port number assumes a port number of 22 (the default for SSH).

Any of the above scenarios may also accept a Hash as the last parameter, specifying a list of additional options to be used to initialize the session. (See Net::SSH::Session.add_options).

Alternatively, named parameters may be used, in which case the first parameter is positional and is always the host to connect to, following which you may specify any of the following named parameters (as symbols):

  • :port
  • :username
  • :password

Any additional parameters are treated as options that configure how the connection behaves.

Allowed options are:

  • :keys (the list of filenames identifying the user’s keys)
  • :host_keys (the list of filenames identifying the host’s keys)
  • :auth_methods (a list of authentication methods to use)
  • :crypto_backend (defaults to :ossl, and specifies the cryptography backend to use)
  • :registry_options (a hash of options to use when creating the registry)
  • :container (the registry to use. If not specified, a new registry will be created)
  • :verbose (how verbose the logging output should be. Defaults to :warn).
  • :log (the name of the file, or the IO object, to which messages will be logged. Defaults to STDERR.)

Also, any options recognized by Net::SSH::Transport::Session may be given, and will be passed through to initialize the transport session.

If a block is given to this method, then it is called with the new session object. The session object is then closed when the block terminates. If a block is not given, then the session object is returned (and must be closed explicitly).

[Source]

     # File lib/net/ssh/session.rb, line 93
 93:       def initialize( *args )
 94:         @open = false
 95:         process_arguments( *args )
 96: 
 97:         @registry.define do |b|
 98:           b.crypto_backend { @crypto_backend }
 99:           b.transport_host { @host }
100:           b.transport_options { @options }
101: 
102:           b.userauth_keys { @keys }
103:           b.userauth_host_keys { @host_keys }
104:           b.userauth_method_order { @auth_methods }
105: 
106:           # Register myself with the registry, so that other services may
107:           # access me.
108:           b.session( :pipeline => [] ) { self }
109: 
110:           b.prompter do
111:             require 'net/ssh/util/prompter'
112:             Net::SSH::Util::Prompter.new
113:           end
114: 
115:           b.require 'net/ssh/transport/services', "Net::SSH::Transport"
116:           b.require 'net/ssh/connection/services', "Net::SSH::Connection"
117:           b.require 'net/ssh/userauth/services', "Net::SSH::UserAuth"
118: 
119:           b.require 'net/ssh/service/services', "Net::SSH::Service"
120:         end
121: 
122:         userauth = @registry[:userauth][:driver]
123:         if userauth.authenticate( "ssh-connection", @username, @password )
124:           @open = true
125:           @connection = @registry[:connection][:driver]
126:           if block_given?
127:             yield self
128:             close
129:           end
130:         else
131:           @registry[:transport][:session].close
132:           raise AuthenticationFailed, @username
133:         end
134:       end

Public Instance methods

Closes the session, if it is open. If it is not open, this does nothing.

[Source]

     # File lib/net/ssh/session.rb, line 138
138:       def close
139:         @registry[:transport][:session].close if @open
140:         @open = false
141:       end

Enters the main communication loop. This processes events occuring over the channel. If a block is given, the loop will continue for as long as the block returns true. Otherwise, the loop continues until there are no more open channels. (See Net::SSH::Connection::Driver#loop).

[Source]

     # File lib/net/ssh/session.rb, line 162
162:       def loop( &block )
163:         sanity_check
164:         @connection.loop(&block)
165:       end

Provides convenient access to services that have been registered with the session, such as "process" and "forward".

Usage:

  session.forward.local(...)

[Source]

     # File lib/net/ssh/session.rb, line 173
173:       def method_missing( sym, *args, &block )
174:         if args.empty? && block.nil? && @registry[:services].has_key?( sym )
175:           return @registry[:services][ sym ]
176:         else
177:           super
178:         end
179:       end

Returns true if the session is currently open.

[Source]

     # File lib/net/ssh/session.rb, line 144
144:       def open?
145:         @open
146:       end

Opens a new communication channel over the current connection. This returns immediately. The block will be invoked when then the channel has been opened. (See Net::SSH::Connection::Driver#open_channel).

[Source]

     # File lib/net/ssh/session.rb, line 151
151:       def open_channel( type="session", data=nil, &block )
152:         sanity_check
153:         channel = @connection.open_channel( type, data )
154:         channel.on_confirm_open(&block)
155:         channel
156:       end

[Validate]