Class: Kitchen::Transport::Ssh::Connection

Inherits:
Base::Connection show all
Defined in:
lib/kitchen/transport/ssh.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:

Instance Method Summary collapse

Methods inherited from Base::Connection

#execute_with_retry, #retry?

Methods included from Logging

#banner, #debug, #error, #fatal, #info, #warn

Constructor Details

#initialize(config = {}) {|self| ... } ⇒ Object

Create a new Connection instance.

Parameters:

  • options (Hash)

    connection options

Yields:

  • (self)

    yields itself for block-style invocation


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# File 'lib/kitchen/transport/ssh.rb', line 119

def initialize(config = {})
  super(config)
  @session = nil
end

Instance Method Details

#closeObject

Closes the session connection, if it is still active.


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# File 'lib/kitchen/transport/ssh.rb', line 125

def close
  return if @session.nil?

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

#download(remotes, local) ⇒ Object

Download remote files or directories to local host.

Parameters:

  • remotes (Array<String>)

    paths to remote files or directories

  • local (String)

    path to local destination. If `local` is an existing directory, `remote` will be downloaded into the directory using its original name

Raises:

  • (TransportFailed)

    if the files could not all be downloaded successfully, which may vary by implementation


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# File 'lib/kitchen/transport/ssh.rb', line 193

def download(remotes, local)
  # ensure the parent dir of the local target exists
  FileUtils.mkdir_p(File.dirname(local))

  Array(remotes).each do |file|
    begin
      logger.debug("Attempting to download '#{file}' as file")
      session.scp.download!(file, local)
    rescue Net::SCP::Error
      begin
        logger.debug("Attempting to download '#{file}' as directory")
        session.scp.download!(file, local, recursive: true)
      rescue Net::SCP::Error
        logger.warn(
          "SCP download failed for file or directory '#{file}', perhaps it does not exist?"
        )
      end
    end
  end
rescue Net::SSH::Exception => ex
  raise SshFailed, "SCP download failed (#{ex.message})"
end

#execute(command) ⇒ Object

Execute a command on the remote host.

Parameters:

  • command (String)

    command string to execute

Raises:

  • (TransportFailed)

    if the command does not exit successfully, which may vary by implementation


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# File 'lib/kitchen/transport/ssh.rb', line 135

def execute(command)
  return if command.nil?

  logger.debug("[SSH] #{self} (#{command})")
  exit_code = execute_with_exit_code(command)

  if exit_code != 0
    raise Transport::SshFailed.new(
      "SSH exited (#{exit_code}) for command: [#{command}]",
      exit_code
    )
  end
rescue Net::SSH::Exception => ex
  raise SshFailed, "SSH command failed (#{ex.message})"
end

#login_commandLoginCommand

Builds a LoginCommand which can be used to open an interactive session on the remote host.

Returns:

  • (LoginCommand)

    an object containing the array of command line tokens and exec options to be used in a fork/exec

Raises:


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# File 'lib/kitchen/transport/ssh.rb', line 152

def 
  args  = %w{ -o UserKnownHostsFile=/dev/null }
  args += %w{ -o StrictHostKeyChecking=no }
  args += %w{ -o IdentitiesOnly=yes } if options[:keys]
  args += %W{ -o LogLevel=#{logger.debug? ? "VERBOSE" : "ERROR"} }
  if options.key?(:forward_agent)
    args += %W{ -o ForwardAgent=#{options[:forward_agent] ? "yes" : "no"} }
  end
  if ssh_gateway
    gateway_command = "ssh -q #{ssh_gateway_username}@#{ssh_gateway} nc #{hostname} #{port}"
    args += %W{ -o ProxyCommand=#{gateway_command} -p #{ssh_gateway_port} }
  end
  Array(options[:keys]).each { |ssh_key| args += %W{ -i #{ssh_key} } }
  args += %W{ -p #{port} }
  args += %W{ #{username}@#{hostname} }

  LoginCommand.new("ssh", args)
end

#upload(locals, remote) ⇒ Object

Uploads local files or directories to remote host.

Parameters:

  • locals (Array<String>)

    paths to local files or directories

  • remote (String)

    path to remote destination

Raises:

  • (TransportFailed)

    if the files could not all be uploaded successfully, which may vary by implementation


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# File 'lib/kitchen/transport/ssh.rb', line 172

def upload(locals, remote)
  logger.debug("TIMING: scp async upload (Kitchen::Transport::Ssh)")
  elapsed = Benchmark.measure do
    waits = []
    Array(locals).map do |local|
      opts = File.directory?(local) ? { recursive: true } : {}

      waits.push session.scp.upload(local, remote, opts) do |_ch, name, sent, total|
        logger.debug("Async Uploaded #{name} (#{total} bytes)") if sent == total
      end
      waits.shift.wait while waits.length >= max_ssh_sessions
    end
    waits.each(&:wait)
  end
  delta = Util.duration(elapsed.real)
  logger.debug("TIMING: scp async upload (Kitchen::Transport::Ssh) took #{delta}")
rescue Net::SSH::Exception => ex
  raise SshFailed, "SCP upload failed (#{ex.message})"
end

#wait_until_readyObject

Block and return only when the remote host is prepared and ready to execute command and upload files. The semantics and details will vary by implementation, but a round trip through the hosted service is preferred to simply waiting on a socket to become available.


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# File 'lib/kitchen/transport/ssh.rb', line 217

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