wip - Fix node to avoid losing track of subprocesses

labrad/node/__init__.py

@@ -97,6 +97,68 @@
 LOG_LENGTH = 1000 # maximum number of lines of stdout to keep per server
 
 
+class ServerConfig(object):
+    @classmethod
+    def from_config(cls, path, filename, conf):
+        if isinstance(conf, bytes):
+            conf = conf.decode('utf-8')
+        scp = ConfigParser()
+        scp.readfp(io.StringIO(conf))
+
+        # general information
+        name = scp.get('info', 'name', raw=True)
+        description = scp.get('info', 'description', raw=True)
+        if scp.has_option('info', 'version'):
+            version = scp.get('info', 'version', raw=True)
+        else:
+            version = '0.0'
+        try:
+            instancename = scp.get('info', 'instancename', raw=True)
+        except:
+            instancename = name
+
+        # startup
+        platform_cmdline_option = 'cmdline_{}'.format(sys.platform)
+        if scp.has_option('startup', platform_cmdline_option):
+            # use platform-specific command line
+            cmdline = scp.get('startup', platform_cmdline_option, raw=True)
+        else:
+            # use generic command line
+            cmdline = scp.get('startup', 'cmdline', raw=True)
+        try:
+            timeout = float(scp.getint('startup', 'timeout'))
+        except:
+            timeout = None
+
+        # shutdown
+        if scp.has_option('shutdown', 'message'):
+            shutdownMode = 'message', int(scp.get('shutdown', 'message', raw=True))
+        elif scp.has_option('shutdown', 'setting'):
+            shutdownMode = 'setting', scp.get('shutdown', 'setting', raw=True)
+        try:
+            shutdownTimeout = float(scp.getint('shutdown', 'timeout'))
+        except:
+            shutdownTimeout = None
+
+        return cls(name, description, version, instancename, cmdline, path,
+                   filename, timeout, shutdownMode, shutdownTimeout)
+
+    def __init__(self, name, description, version, instancename, cmdline, path,
+                 filename, timeout, shutdownMode, shutdownTimeout):
+        self.name = name
+        self.description = description
+        self.version = version
+        self.instancename = instancename
+        self.environVars = findEnvironmentVars(instancename)
+        self.isLocal = len(self.environVars) > 0
+        self.cmdline = cmdline
+        self.path = path
+        self.filename = filename
+        self.timeout = timeout
+        self.shutdownMode = shutdownMode
+        self.shutdownTimeout = shutdownTimeout
+
+
 class ServerProcess(ProcessProtocol):
     """A class to represent a running server instance."""
 
@@ -772,6 +834,11 @@ def start(self, c, name, environ={}):
         """Start an instance of a server."""
         if name not in self.servers:
             raise Exception("Unknown server: '%s'." % name)
+        # check whether an instance with this name already exists
+        if name in self.instances:
+            prev = self.instances[name]
+            if prev.status not in ['STOPPING', 'STOPPED']:
+                raise ValueError('server already running')
         environ = dict(environ) # copy context environment
         environ.update(LABRADNODE=self.nodename,
                        LABRADHOST=self.host,
@@ -781,7 +848,6 @@ def start(self, c, name, environ={}):
             environ.update(LABRADUSER=self.credential.username,
                            LABRADPASSWORD=self.credential.password)
         srv = self.servers[name](environ)
-        # TODO check whether an instance with this name already exists
         self.instances[name] = srv
         yield srv.start()
         returnValue(srv.name)