bitbake: bitbake, xmlrpc.py: Implement memory resident auto port configuration/restart

This patch adds the ability to dynamically select a port for the
bitbake memory resident server when the BBSERVER port is set to -1.
This allows for running multiple instances of the bitbake memory
resident server on the same system in different build directories.

The client portion of the bitbake instance can also request that the
server automatically start when using the auto port feature.  This is
to deal with a bitbake instance that eventually times out and exits or
that has died for some unknown reason.

The new functionality allows for lazy startup of the server after
sourcing the init script for the memory resident functionality.

(Bitbake rev: d6abc07ff385357d312d8435b89e0a9c1f965433)

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/server/xmlrpc.py

@@ -338,13 +338,38 @@ class BitBakeXMLRPCClient(BitBakeBaseServer):
     def saveConnectionDetails(self, remote):
         self.remote = remote
 
+    def saveConnectionConfigParams(self, configParams):
+        self.configParams = configParams
+
     def establishConnection(self, featureset):
         # The format of "remote" must be "server:port"
         try:
             [host, port] = self.remote.split(":")
             port = int(port)
-        except:
-            return None
+        except Exception as e:
+            bb.fatal("Failed to read remote definition (%s)" % str(e))
+
+        # use automatic port if port set to -1, meaning read it from
+        # the bitbake.lock file
+        if port == -1:
+            lock_location = "%s/bitbake.lock" % self.configParams.environment.get('BUILDDIR')
+            lock = bb.utils.lockfile(lock_location, False, False)
+            if lock:
+                # This means there is no server running which we can
+                # connect to on the local system.
+                bb.utils.unlockfile(lock)
+                return None
+
+            try:
+                lf = open(lock_location, 'r')
+                remotedef = lf.readline()
+                [host, port] = remotedef.split(":")
+                port = int(port)
+                lf.close()
+                self.remote = remotedef
+            except Exception as e:
+                bb.fatal("Failed to read bitbake.lock (%s)" % str(e))
+
         # We need our IP for the server connection. We get the IP
         # by trying to connect with the server
         try:
@@ -352,8 +377,8 @@ class BitBakeXMLRPCClient(BitBakeBaseServer):
             s.connect((host, port))
             ip = s.getsockname()[0]
             s.close()
-        except:
-            return None
+        except Exception as e:
+            bb.fatal("Could not create socket for %s:%s (%s)" % (host, port, str(e)))
         try:
             self.serverImpl = XMLRPCProxyServer(host, port)
             self.connection = BitBakeXMLRPCServerConnection(self.serverImpl, (ip, 0), self.observer_only, featureset)