Class: Xshellz::Ssh::NetSshTransport

Inherits:
Object
  • Object
show all
Defined in:
lib/xshellz/ssh.rb

Overview

Real SSH transport: exec over a session channel, files over SFTP.

The private key is handed to net-ssh in memory via key_data - it never touches disk. Requires the ed25519 + bcrypt_pbkdf gems (declared as runtime dependencies) for net-ssh to accept ed25519 keys.

Constant Summary collapse

POLL_INTERVAL = 
0.02

Instance Method Summary collapse

Constructor Details

#initialize(host:, port:, private_key_openssh:, username: "root", connect_timeout: 30) ⇒ NetSshTransport

Returns a new instance of NetSshTransport.



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# File 'lib/xshellz/ssh.rb', line 56

def initialize(host:, port:, private_key_openssh:, username: "root", connect_timeout: 30)
  @ssh = Net::SSH.start(
    host,
    username,
    port: port,
    key_data: [private_key_openssh],
    keys: [],
    keys_only: true,
    auth_methods: ["publickey"],
    non_interactive: true,
    # Sandbox host keys are minted at spawn time; nothing to pin against.
    verify_host_key: :never,
    timeout: connect_timeout
  )
  @sftp = nil
end

Instance Method Details

#close ⇒ Object 



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# File 'lib/xshellz/ssh.rb', line 134

def close
  @sftp = nil
  @ssh.close unless @ssh.closed?
end

#download(remote_path, local_path) ⇒ Object 



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# File 'lib/xshellz/ssh.rb', line 129

def download(remote_path, local_path)
  sftp.download!(remote_path, local_path)
  nil
end

#exec(command, timeout: nil, &block) ⇒ Object

Execute a command; optional block receives (:stdout | :stderr, chunk) as output arrives. Returns a CommandResult; a non-zero exit code does NOT raise.



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# File 'lib/xshellz/ssh.rb', line 76

def exec(command, timeout: nil, &block)
  stdout = +""
  stderr = +""
  exit_code = nil

  channel = @ssh.open_channel do |ch|
    ch.exec(command) do |_, success|
      raise Error, "Failed to start command on the sandbox: #{command.inspect}" unless success

      ch.on_data do |_, data|
        stdout << data
        block&.call(:stdout, data)
      end
      ch.on_extended_data do |_, _type, data|
        stderr << data
        block&.call(:stderr, data)
      end
      ch.on_request("exit-status") do |_, buffer|
        exit_code = buffer.read_long
      end
    end
  end

  deadline = timeout && (monotonic + timeout)
  timed_out = false
  @ssh.loop(POLL_INTERVAL) do
    timed_out = !deadline.nil? && monotonic > deadline
    channel.active? && !timed_out
  end

  if timed_out && channel.active?
    close_channel_quietly(channel)
    raise CommandTimeoutError,
          "Command did not finish within #{timeout} seconds: #{command.inspect}"
  end

  CommandResult.new(stdout: stdout, stderr: stderr, exit_code: exit_code || -1)
end

#read_file(path) ⇒ Object 



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# File 'lib/xshellz/ssh.rb', line 115

def read_file(path)
  sftp.download!(path)
end

#upload(local_path, remote_path) ⇒ Object 



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# File 'lib/xshellz/ssh.rb', line 124

def upload(local_path, remote_path)
  sftp.upload!(local_path, remote_path)
  nil
end

#write_file(path, data) ⇒ Object 



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# File 'lib/xshellz/ssh.rb', line 119

def write_file(path, data)
  sftp.upload!(StringIO.new(data), path)
  nil
end