Class: Beaker::SshConnection

Inherits:
Object
  • Object
show all
Defined in:
lib/beaker/ssh_connection.rb

Constant Summary collapse

RETRYABLE_EXCEPTIONS = 
[
  SocketError,
  Timeout::Error,
  Errno::ETIMEDOUT,
  Errno::EHOSTDOWN,
  Errno::EHOSTUNREACH,
  Errno::ECONNREFUSED,
  Errno::ECONNRESET,
  Errno::ENETUNREACH,
  Net::SSH::Disconnect,
  Net::SSH::AuthenticationFailed,
  IOError,
]

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(hostname, user = nil, ssh_opts = {}, options = {}) ⇒ SshConnection

Returns a new instance of SshConnection.



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# File 'lib/beaker/ssh_connection.rb', line 24

def initialize hostname, user = nil, ssh_opts = {}, options = {}
  @hostname = hostname
  @user = user
  @ssh_opts = ssh_opts
  @logger = options[:logger]
  @options = options
end

Instance Attribute Details

#logger ⇒ Object

Returns the value of attribute logger.



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# File 'lib/beaker/ssh_connection.rb', line 8

def logger
  @logger
end

Class Method Details

.connect(hostname, user = 'root', ssh_opts = {}, options = {}) ⇒ Object 



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# File 'lib/beaker/ssh_connection.rb', line 32

def self.connect hostname, user = 'root', ssh_opts = {}, options = {}
  connection = new hostname, user, ssh_opts, options
  connection.connect
  connection
end

Instance Method Details

#close ⇒ Object

closes this SshConnection



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# File 'lib/beaker/ssh_connection.rb', line 62

def close
  begin
    if @ssh and not @ssh.closed?
      @ssh.close
    else
      @logger.warn("ssh.close: connection is already closed, no action needed")
    end
  rescue *RETRYABLE_EXCEPTIONS => e
    @logger.warn "Attemped ssh.close, (caught #{e.class.name} - #{e.message})."
  rescue => e
    @logger.warn "ssh.close threw unexpected Error: #{e.class.name} - #{e.message}.  Shutting down, and re-raising error below"
    @ssh.shutdown!
    raise e
  ensure
    @ssh = nil
    @logger.warn("ssh connection to #{@hostname} has been terminated")
  end
end

#connect ⇒ Object

connect to the host



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# File 'lib/beaker/ssh_connection.rb', line 39

def connect
  try = 1
  last_wait = 0
  wait = 1
  @ssh ||= begin
             @logger.debug "Attempting ssh connection to #{@hostname}, user: #{@user}, opts: #{@ssh_opts}"
             Net::SSH.start(@hostname, @user, @ssh_opts)
           rescue *RETRYABLE_EXCEPTIONS => e
             if try <= 11
               @logger.warn "Try #{try} -- Host #{@hostname} unreachable: #{e.class.name} - #{e.message}"
               @logger.warn "Trying again in #{wait} seconds"
               sleep wait
              (last_wait, wait) = wait, last_wait + wait
               try += 1
               retry
             else
               @logger.error "Failed to connect to #{@hostname}"
               raise
             end
           end
end

#execute(command, options = {}, stdout_callback = nil, stderr_callback = stdout_callback) ⇒ Object 



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# File 'lib/beaker/ssh_connection.rb', line 145

def execute command, options = {}, stdout_callback = nil,
            stderr_callback = stdout_callback
  try = 1
  wait = 1
  last_wait = 0
  begin
    # ensure that we have a current connection object
    connect
    result = try_to_execute(command, options, stdout_callback, stderr_callback)
  rescue *RETRYABLE_EXCEPTIONS => e
    if try < 11
       sleep wait
      (last_wait, wait) = wait, last_wait + wait
       try += 1
      @logger.error "Command execution '#{@hostname}$ #{command}' failed (#{e.class.name} - #{e.message})"
      close
      @logger.debug "Preparing to retry: closed ssh object"
      retry
    else
      raise
    end
  end

  result
end

#process_stdin_for(channel, stdin) ⇒ Object 



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# File 'lib/beaker/ssh_connection.rb', line 206

def process_stdin_for channel, stdin
  # queue stdin data, force it to packets, and signal eof: this
  # triggers action in many remote commands, notably including
  # 'puppet apply'.  It must be sent at some point before the rest
  # of the action.
  channel.send_data stdin.to_s
  channel.process
  channel.eof!
end

#register_exit_code_for(channel, output) ⇒ Object 



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# File 'lib/beaker/ssh_connection.rb', line 200

def register_exit_code_for channel, output
  channel.on_request("exit-status") do |ch, data|
    output.exit_code = data.read_long
  end
end

#register_stderr_for(channel, output, callback = nil) ⇒ Object 



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# File 'lib/beaker/ssh_connection.rb', line 190

def register_stderr_for channel, output, callback = nil
  channel.on_extended_data do |ch, type, data|
    if type == 1
      callback[data] if callback
      output.stderr << data
      output.output << data
    end
  end
end

#register_stdout_for(channel, output, callback = nil) ⇒ Object 



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# File 'lib/beaker/ssh_connection.rb', line 182

def register_stdout_for channel, output, callback = nil
  channel.on_data do |ch, data|
    callback[data] if callback
    output.stdout << data
    output.output << data
  end
end

#request_terminal_for(channel, command) ⇒ Object 



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# File 'lib/beaker/ssh_connection.rb', line 171

def request_terminal_for channel, command
  channel.request_pty do |ch, success|
    if success
      @logger.debug "Allocated a PTY on #{@hostname} for #{command.inspect}"
    else
      abort "FAILED: could not allocate a pty when requested on " +
        "#{@hostname} for #{command.inspect}"
    end
  end
end

#scp_from(source, target, options = {}, dry_run = false) ⇒ Object 



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# File 'lib/beaker/ssh_connection.rb', line 241

def scp_from source, target, options = {}, dry_run = false
  return if dry_run

  local_opts = options.dup
  if local_opts[:recursive].nil?
    local_opts[:recursive] = true
  end
  local_opts[:chunk_size] ||= 16384

  result = Result.new(@hostname, [source, target])
  result.stdout = "\n"
  @ssh.scp.download! source, target, local_opts do |ch, name, sent, total|
    result.stdout << "\tcopying %s: %10d/%d\n" % [name, sent, total]
  end

  # Setting these values allows reporting via result.log(test_name)
  result.stdout << "  SCP'ed file #{@hostname}:#{source} to #{target}"

  # Net::Scp always returns 0, so just set the return code to 0.
  result.exit_code = 0

  result.finalize!
  result
end

#scp_to(source, target, options = {}, dry_run = false) ⇒ Object 



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# File 'lib/beaker/ssh_connection.rb', line 216

def scp_to source, target, options = {}, dry_run = false
  return if dry_run

  local_opts = options.dup
  if local_opts[:recursive].nil?
    local_opts[:recursive] = File.directory?(source)
  end
  local_opts[:chunk_size] ||= 16384

  result = Result.new(@hostname, [source, target])
  result.stdout = "\n"
  @ssh.scp.upload! source, target, local_opts do |ch, name, sent, total|
    result.stdout << "\tcopying %s: %10d/%d\n" % [name, sent, total]
  end

  # Setting these values allows reporting via result.log(test_name)
  result.stdout << "  SCP'ed file #{source} to #{@hostname}:#{target}"

  # Net::Scp always returns 0, so just set the return code to 0.
  result.exit_code = 0

  result.finalize!
  return result
end

#try_to_execute(command, options = {}, stdout_callback = nil, stderr_callback = stdout_callback) ⇒ Object 



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# File 'lib/beaker/ssh_connection.rb', line 107

def try_to_execute command, options = {}, stdout_callback = nil,
            stderr_callback = stdout_callback

  result = Result.new(@hostname, command)
  # why are we getting to this point on a dry run anyways?
  # also... the host creates connections through the class method,
  # which automatically connects, so you can't do a dry run unless you also
  # can connect to your hosts?
  return result if options[:dry_run]

  @ssh.open_channel do |channel|
    request_terminal_for( channel, command ) if options[:pty]

    channel.exec(command) do |terminal, success|
      abort "FAILED: to execute command on a new channel on #{@hostname}" unless success
      register_stdout_for terminal, result, stdout_callback
      register_stderr_for terminal, result, stderr_callback
      register_exit_code_for terminal, result

      process_stdin_for( terminal, options[:stdin] ) if options[:stdin]
    end
  end

  # Process SSH activity until we stop doing that - which is when our
  # channel is finished with...
  begin
    @ssh.loop
  rescue *RETRYABLE_EXCEPTIONS => e
    # this would indicate that the connection failed post execution, since the channel exec was successful
    @logger.warn "ssh channel on #{@hostname} received exception post command execution #{e.class.name} - #{e.message}"
    close
  end

  result.finalize!
  @logger.last_result = result
  result
end

#wait_for_connection_failure ⇒ Object

We expect the connection to close so wait for that to happen



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# File 'lib/beaker/ssh_connection.rb', line 82

def wait_for_connection_failure
  try = 1
  last_wait = 0
  wait = 1
  while try < 11
    begin
      @logger.debug "Waiting for connection failure on #{@hostname} (attempt #{try}, try again in #{wait} second(s))"
      @ssh.open_channel do |channel|
        channel.exec('') #Just send something down the pipe
      end
      loop_tries = 0
      #loop is actually loop_forver, so let it try 3 times and then quit instead of endless blocking
      @ssh.loop { loop_tries += 1 ; loop_tries < 4 }
    rescue *RETRYABLE_EXCEPTIONS => e
      @logger.debug "Connection on #{@hostname} failed as expected (#{e.class.name} - #{e.message})"
      close #this connection is bad, shut it down
      return true
    end
    sleep wait
    (last_wait, wait) = wait, last_wait + wait
    try += 1
  end
  false
end