Class: Train::Transports::SSH::Connection

Inherits:
BaseConnection
  • Object
show all
Defined in:
lib/train/transports/ssh_connection.rb

Overview

A Connection instance can be generated and re-generated, given new connection details such as connection port, hostname, credentials, etc. This object is responsible for carrying out the actions on the remote host such as executing commands, transferring files, etc.

Author:

Defined Under Namespace

Classes: OS

Instance Method Summary collapse

Constructor Details

#initialize(options) ⇒ Connection

rubocop:disable Metrics/ClassLength



33
34
35
36
37
38
39
40
41
42
43
44
45
 
# File 'lib/train/transports/ssh_connection.rb', line 33

def initialize(options)
  super(options)
  @username               = @options.delete(:username)
  @hostname               = @options.delete(:hostname)
  @port                   = @options[:port] # don't delete from options
  @connection_retries     = @options.delete(:connection_retries)
  @connection_retry_sleep = @options.delete(:connection_retry_sleep)
  @max_wait_until_ready   = @options.delete(:max_wait_until_ready)
  @session                = nil
  @transport_options      = @options.delete(:transport_options)
  @cmd_wrapper            = nil
  @cmd_wrapper            = CommandWrapper.load(self, @transport_options)
end

Instance Method Details

#close ⇒ Object 



48
49
50
51
52
53
54
 
# File 'lib/train/transports/ssh_connection.rb', line 48

def close
  return if @session.nil?
  logger.debug("[SSH] closing connection to #{self}")
  session.close
ensure
  @session = nil
end

#file(path) ⇒ Object 



60
61
62
63
64
65
66
67
68
69
 
# File 'lib/train/transports/ssh_connection.rb', line 60

def file(path)
  @files[path] ||= \
    if os.aix?
      AixFile.new(self, path)
    elsif os.solaris?
      UnixFile.new(self, path)
    else
      LinuxFile.new(self, path)
    end
end

#login_command ⇒ Object 



110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
 
# File 'lib/train/transports/ssh_connection.rb', line 110

def 
  level = logger.debug? ? 'VERBOSE' : 'ERROR'
  fwd_agent = options[:forward_agent] ? 'yes' : 'no'

  args  = %w{ -o UserKnownHostsFile=/dev/null }
  args += %w{ -o StrictHostKeyChecking=no }
  args += %w{ -o IdentitiesOnly=yes } if options[:keys]
  args += %W( -o LogLevel=#{level} )
  args += %W( -o ForwardAgent=#{fwd_agent} ) if options.key?(:forward_agent)
  Array(options[:keys]).each do |ssh_key|
    args += %W( -i #{ssh_key} )
  end
  args += %W( -p #{@port} )
  args += %W( #{@username}@#{@hostname} )

  LoginCommand.new('ssh', args)
end

#os ⇒ Object 



56
57
58
 
# File 'lib/train/transports/ssh_connection.rb', line 56

def os
  @os ||= OS.new(self)
end

#run_command(cmd) ⇒ Object 



72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
 
# File 'lib/train/transports/ssh_connection.rb', line 72

def run_command(cmd)
  stdout = stderr = ''
  exit_status = nil
  cmd.dup.force_encoding('binary') if cmd.respond_to?(:force_encoding)
  logger.debug("[SSH] #{self} (#{cmd})")

  session.open_channel do |channel|
    # wrap commands if that is configured
    cmd = @cmd_wrapper.run(cmd) unless @cmd_wrapper.nil?

    channel.exec(cmd) do |_, success|
      abort 'Couldn\'t execute command on SSH.' unless success

      channel.on_data do |_, data|
        stdout += data
      end

      channel.on_extended_data do |_, _type, data|
        stderr += data
      end

      channel.on_request('exit-status') do |_, data|
        exit_status = data.read_long
      end

      channel.on_request('exit-signal') do |_, data|
        exit_status = data.read_long
      end
    end
  end
  @session.loop

  CommandResult.new(stdout, stderr, exit_status)
rescue Net::SSH::Exception => ex
  raise Train::Transports::SSHFailed, "SSH command failed (#{ex.message})"
end

#upload(locals, remote) ⇒ Object 



129
130
131
132
133
134
135
136
137
138
139
 
# File 'lib/train/transports/ssh_connection.rb', line 129

def upload(locals, remote)
  Array(locals).each do |local|
    opts = File.directory?(local) ? { recursive: true } : {}

    session.scp.upload!(local, remote, opts) do |_ch, name, sent, total|
      logger.debug("Uploaded #{name} (#{total} bytes)") if sent == total
    end
  end
rescue Net::SSH::Exception => ex
  raise Train::Transports::SSHFailed, "SCP upload failed (#{ex.message})"
end

#uri ⇒ Object 



153
154
155
 
# File 'lib/train/transports/ssh_connection.rb', line 153

def uri
  "ssh://#{@username}@#{@hostname}:#{@port}"
end

#wait_until_ready ⇒ Object 



142
143
144
145
146
147
148
149
150
151
 
# File 'lib/train/transports/ssh_connection.rb', line 142

def wait_until_ready
  delay = 3
  session(
    retries: @max_wait_until_ready / delay,
    delay:   delay,
    message: "Waiting for SSH service on #{@hostname}:#{@port}, " \
             "retrying in #{delay} seconds",
  )
  execute(PING_COMMAND.dup)
end