bootstrap image: Add remote command execution script

In order to automate the complete bootstrap build process we need a
mechanism to control the second phase which builds the final packages
on the booted bootstrap Haiku. To avoid additional dependencies
(buildbot slave, ssh, rsh,...) we'd have to cross-build, there's now a
pair of simple python scripts that allows executing commands on a remote
machine. The server script (bootstrap_daemon.py) is added to the
bootstrap image and started automatically during the boot.

build/jam/images/definitions/bootstrap

@@ -14,3 +14,8 @@ AddFilesToHaikuImage home haikuports
 local formatVersionsFile = <haikuports>FormatVersions ;
 SEARCH on $(formatVersionsFile) = $(HAIKU_PORTS) ;
 AddFilesToHaikuImage home haikuports : $(formatVersionsFile) ;
+
+# bootstrap daemon
+local bootstrapDaemon = <haiku-image>bootstrap_daemon.py ;
+SEARCH on $(bootstrapDaemon) = [ FDirName $(HAIKU_TOP) build scripts ] ;
+AddFilesToHaikuImage home config settings boot launch : $(bootstrapDaemon) ;

build/scripts/bootstrap_client.py

@@ -0,0 +1,85 @@
+#!/usr/bin/env python
+#
+# Usage: bootstrap_client.py <address>[:port] <command> ...
+#
+# <command> and the following arguments are concatenated (separated by a space)
+# and passed to a shell on the server.
+
+import os
+import select
+import socket
+import sys
+
+
+port = 4242
+bufferSize = 4 * 1024
+
+# interpret command line args
+if len(sys.argv) < 3:
+	sys.exit('Usage: ' + sys.argv[0] + ' <address>[:<port>] <command>')
+
+address = sys.argv[1]
+portIndex = address.find(':')
+if portIndex >= 0:
+	port = int(address[portIndex + 1:])
+	address = address[:portIndex]
+
+commandToRun = " ".join(sys.argv[2:])
+
+# create sockets and connect to server
+controlConnection = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+stdioConnection = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+stderrConnection = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+
+try:
+	controlConnection.connect((address, port))
+	stdioConnection.connect((address, port))
+	stderrConnection.connect((address, port))
+except socket.error, msg:
+	sys.exit('Failed to connect to %s port %d: %s' % (address, port, msg[1]))
+
+# send command length and command
+controlConnection.send("%08d" % len(commandToRun))
+controlConnection.send(commandToRun)
+
+# I/O loop. We quit when all sockets have been closed.
+exitCode = ''
+connections = [controlConnection, stdioConnection, stderrConnection, sys.stdin]
+
+while connections and (len(connections) > 1 or not sys.stdin in connections):
+	(readable, writable, exceptions) = select.select(connections, [],
+		connections)
+
+	if sys.stdin in readable:
+		data = sys.stdin.readline(bufferSize)
+		if data:
+			stdioConnection.send(data)
+		else:
+			connections.remove(sys.stdin)
+			stdioConnection.shutdown(socket.SHUT_WR)
+
+	if stdioConnection in readable:
+		data = stdioConnection.recv(bufferSize)
+		if data:
+			sys.stdout.write(data)
+		else:
+			connections.remove(stdioConnection)
+		
+	if stderrConnection in readable:
+		data = stderrConnection.recv(bufferSize)
+		if data:
+			sys.stderr.write(data)
+		else:
+			connections.remove(stderrConnection)
+		
+	if controlConnection in readable:
+		data = controlConnection.recv(bufferSize)
+		if data:
+			exitCode += data
+		else:
+			connections.remove(controlConnection)
+
+# either an exit code has been sent or we consider this an error
+if exitCode:
+	sys.exit(int(exitCode))
+sys.exit(1)

build/scripts/bootstrap_daemon.py

@@ -0,0 +1,61 @@
+#!/usr/bin/env python
+
+import socket
+import subprocess
+import sys
+
+
+address = '0.0.0.0'
+port = 4242
+
+
+def receiveExactly(connection, size):
+	data = '';
+	while size > 0:
+		dataReceived = connection.recv(size)
+		if not dataReceived:
+			raise EOFError()
+		data += dataReceived
+		size -= len(dataReceived)
+	return data
+
+
+def handleConnection(listenerSocket):
+	(controlConnection, controlAddress) = listenerSocket.accept()
+	(stdioConnection, stdioAddress) = listenerSocket.accept()
+	(stderrConnection, stderrAddress) = listenerSocket.accept()
+
+	print 'accepted client connections'
+
+	try:
+		commandLength = receiveExactly(controlConnection, 8)
+		commandToRun = receiveExactly(controlConnection, int(commandLength))
+
+		print 'received command: ' + commandToRun
+
+		exitCode = subprocess.call(commandToRun, stdin=stdioConnection,
+			stdout=stdioConnection, stderr=stderrConnection, shell=True)
+
+		controlConnection.send(str(exitCode))
+	finally:
+		controlConnection.close()
+		stdioConnection.close()
+		stderrConnection.close()
+
+	print 'client connections closed'
+
+
+listenerSocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+listenerSocket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+
+try:
+	listenerSocket.bind((address, port))
+except socket.error, msg:
+	sys.exit('Failed to bind to %s port %d: %s' % (address, port, msg[1]))
+
+listenerSocket.listen(3)
+
+print 'started listening on adddress %s port %s' % (address, port)
+
+while True:
+	handleConnection(listenerSocket)