daemon: Add a startup service.

When enabled, the startup service ensures that other node services
start in order (according to the service _startindex value) and that
the prior service completes before the next service starts.  It also
captures any output from startup commands in a file named
'startup.log'.

daemon/core/service.py

@@ -63,6 +63,7 @@ class CoreServices(ConfigurableManager):
             for path in paths.split(','):
                 path = path.strip()
                 self.importcustom(path)
+        self.isStartupService = startup.Startup.isStartupService
 
     def importcustom(self, path):
         ''' Import services from a myservices directory.
@@ -217,24 +218,25 @@ class CoreServices(ConfigurableManager):
         '''
         services = sorted(node.services,
                           key=lambda service: service._startindex)
+        useStartupService = any(map(self.isStartupService, services))
         for s in services:
             if len(str(s._starttime)) > 0:
                 try:
                     t = float(s._starttime)
                     if t > 0.0:
                         fn = self.bootnodeservice                    
-                        self.session.evq.add_event(t, fn, node, s, services)
+                        self.session.evq.add_event(t, fn, node, s, services, False)
                         continue
                 except ValueError:
                     pass
-            self.bootnodeservice(node, s, services)
+            self.bootnodeservice(node, s, services, useStartupService)
     
-    def bootnodeservice(self, node, s, services):
+    def bootnodeservice(self, node, s, services, useStartupService):
         ''' Start a service on a node. Create private dirs, generate config
             files, and execute startup commands.
         '''
         if s._custom:
-            self.bootnodecustomservice(node, s, services)
+            self.bootnodecustomservice(node, s, services, useStartupService)
             return
         if node.verbose:
             node.info("starting service %s (%s)" % (s._name, s._startindex))
@@ -247,6 +249,8 @@ class CoreServices(ConfigurableManager):
         for filename in s.getconfigfilenames(node.objid, services): 
             cfg = s.generateconfig(node,  filename, services)
             node.nodefile(filename,  cfg)
+        if useStartupService and not self.isStartupService(s):
+            return
         for cmd in s.getstartup(node, services):
             try:
                 # NOTE: this wait=False can be problematic!
@@ -254,7 +258,7 @@ class CoreServices(ConfigurableManager):
             except Exception, e:
                 node.warn("error starting command %s: %s" % (cmd, e))
 
-    def bootnodecustomservice(self, node, s, services):
+    def bootnodecustomservice(self, node, s, services, useStartupService):
         ''' Start a custom service on a node. Create private dirs, use supplied
             config files, and execute  supplied startup commands.
         '''
@@ -284,6 +288,9 @@ class CoreServices(ConfigurableManager):
                 continue
             node.nodefile(filename,  cfg)
             
+        if useStartupService and not self.isStartupService(s):
+            return
+
         for cmd in s._startup:
             try:
                 # NOTE: this wait=False can be problematic!

daemon/core/services/__init__.py

@@ -3,4 +3,4 @@
 Services available to nodes can be put in this directory.  Everything listed in
 __all__ is automatically loaded by the main core module.
 """
-__all__ = ["quagga", "nrl", "xorp", "bird", "utility", "security", "ucarp", "dockersvc"]
+__all__ = ["quagga", "nrl", "xorp", "bird", "utility", "security", "ucarp", "dockersvc", 'startup']

daemon/core/services/startup.py

@@ -0,0 +1,37 @@
+from core.service import CoreService, addservice
+from sys import maxint
+from inspect import isclass
+
+class Startup(CoreService):
+    'A CORE service to start other services in order, serially'
+    _name = 'startup'
+    _group = 'Utility'
+    _depends = ()
+    _dirs = ()
+    _configs = ('startup.sh', )
+    _startindex = maxint
+    _startup = ('sh startup.sh', )
+    _shutdown = ()
+    _validate = ()
+
+    @staticmethod
+    def isStartupService(s):
+        return isinstance(s, Startup) or \
+            (isclass(s) and issubclass(s, Startup))
+
+    @classmethod
+    def generateconfig(cls, node, filename, services):
+        if filename != cls._configs[0]:
+            return ''
+        script = '#!/bin/sh\n' \
+                 '# auto-generated by Startup (startup.py)\n\n' \
+                 'exec > startup.log 2>&1\n\n'
+        for s in sorted(services, key = lambda x: x._startindex):
+            if cls.isStartupService(s) or len(str(s._starttime)) > 0:
+                continue
+            start = '\n'.join(s.getstartup(node, services))
+            if start:
+                script += start + '\n'
+        return script
+
+addservice(Startup)