Have the wfagent launcher pass a PYTHONPATH with Capnet Proto module path.

(And configure it in the cloudlab setup scripts relative to where we're
installing the capnet controller and the protocol bindings.)

cloudlab/setup-ext-capnet/setup-capnet-compute.sh

@@ -52,6 +52,9 @@ crudini --set /etc/neutron/plugins/ml2/ml2_conf_capnet.ini DEFAULT interface_dri
 crudini --set /etc/neutron/neutron.conf DEFAULT api_extensions_path \
     /usr/lib/python2.7/dist-packages/networking_capnet/extensions
 
+crudini --set /etc/neutron/plugins/ml2/ml2_conf_capnet.ini capnet pythonpath \
+    /opt/tcloud/capnet/lib/python2.7/site-packages
+
 ##
 ## Setup our physical Capnet connections
 ##

cloudlab/setup-ext-capnet/setup-capnet-controller.sh

@@ -57,6 +57,9 @@ else
 	ml2 extension_drivers "capnet"
 fi
 
+crudini --set /etc/neutron/plugins/ml2/ml2_conf_capnet.ini capnet pythonpath \
+    /opt/tcloud/capnet/lib/python2.7/site-packages
+
 crudini --set /etc/neutron/neutron.conf DEFAULT verbose True
 crudini --set /etc/neutron/neutron.conf DEFAULT debug True
 

cloudlab/setup-ext-capnet/setup-capnet-networkmanager.sh

@@ -60,6 +60,9 @@ crudini --set /etc/neutron/l3_agent.ini DEFAULT interface_driver \
 crudini --set /etc/neutron/metering_agent.ini DEFAULT interface_driver \
     networking_capnet.agent.linux.interface.CapnetOVSInterfaceDriver
 
+crudini --set /etc/neutron/plugins/ml2/ml2_conf_capnet.ini capnet pythonpath \
+    /opt/tcloud/capnet/lib/python2.7/site-packages
+
 ##
 ## Setup our physical Capnet connections
 ##

etc/neutron/plugins/ml2/ml2_conf_capnet.ini

@@ -57,6 +57,11 @@
 # (StrOpt) Specify whether the WA is in a 'netns' or on a 'node'.
 #default_wfapp_env = netns
 
+# (ListOpt) Specify the path where the Capnet controller client python
+#   bindings are installed (and any other paths you need, as a
+#   comma-separated list).
+#pythonpath = 
+
 # (StrOpt) Specify the filter name of the path to the MUL core binary.
 #   This is a rootwrap-based command, so you add a new command by adding
 #   a new filter in /etc/neutron/rootwrap.d/capnet.filters.  In that

networking_capnet/common/config.py

@@ -76,6 +76,10 @@ capnet_opts = [
     cfg.StrOpt('default_wfapp_env',default='netns',
                help="Specify whether the WA is in a 'netns' or on a 'node'."),
     
+    cfg.ListOpt('pythonpath',
+                default="/opt/tcloud/capnet/lib/python2.7/site-packages",
+                help="Specify the path where the Capnet controller client python bindings are installed (and any other paths you need, as a comma-separated list)"),
+    
     cfg.StrOpt('mul_core_path',default="mul",
                help="Specify the filter name of the path to the MUL core binary.  This is a rootwrap-based command, so you add a new command by adding a new filter in /etc/neutron/rootwrap.d/capnet.filters.  In that file, you'll see a 'mul' filter; add another one just like it, but that points to the binary you want to execute instead.  Give it a custom name that's not already in the file, and set this value to that name.  BUT -- NB -- if you specify a full path, rootwrap will not be used to run this command, and your binary will run with regular neutron privileges!  That is probably not what you want."),
     cfg.StrOpt('mul_core_args',default="-d -l 0 -n",

networking_capnet/tools/wfagent/launcher.py

@@ -2,6 +2,24 @@
 import sys
 import os
 import socket
+import traceback
+
+##
+## Ok, we want the user to be able to specify where the Capnet Protocol
+## bindings are installed, so we can set an appropriate PYTHONPATH
+## before launching their agent.  We put this into the Neutron config
+## files... so we have to load them up.  I don't understand oslo_config,
+## so I'm just doing what neutron-server does... ugh!
+##
+from oslo_config import cfg
+from neutron.common import config
+
+config_file_args = [ '--config-file','/etc/neutron/plugins/ml2/ml2_conf.ini',
+                     '--config-file','/etc/neutron/neutron.conf',
+                     '--config-file','/etc/neutron/plugins/ml2/ml2_conf_capnet.ini' ]
+config.init(config_file_args)
+
+cfg.CONF.import_group('CAPNET','networking_capnet.common.config')
 
 ##
 ## A simple script that execs its args.  Eventually, this script will
@@ -22,12 +40,28 @@ def main():
     os.dup2(lf.fileno(),1)
     os.dup2(lf.fileno(),2)
     
+    extrapaths = []
+    newenviron = dict(os.environ)
+    try:
+        for path in cfg.CONF.CAPNET.pythonpath:
+            extrapaths.append(path)
+        if len(extrapaths) > 0:
+            newenviron['PYTHONPATH'] = ':'.join(extrapaths)
+        pass
+    except:
+        traceback.print_exc()
+        pass
+    
     pid = os.fork()
     if pid == 0:
         pf.write("%d" % (os.getpid(),))
         pf.close()
-        print "DEBUG: running %s" % (str(args),)
-        os.execl(sys.argv[4],*args)
+        if len(extrapaths) > 0:
+            print "DEBUG: running %s (with PYTHONPATH=%s)" % (str(args),newenviron['PYTHONPATH'])
+        else:
+            print "DEBUG: running %s" % (str(args))
+            pass
+        os.execve(sys.argv[4],args,newenviron)
         return -1
     else:
         return 0