Update route reflector configuration when compute nodes are added to/removed from the deployment

Change-Id: I5443489a0921594381832a0ee2fedb384e85e4a9

deployment_scripts/calico-fuel-monitor

@@ -0,0 +1,40 @@
+#!/usr/bin/env python
+
+import pyinotify
+import subprocess
+import yaml
+
+from pluginutils import NODES_CONFIG
+
+RECONFIGURE_ROUTE_REFLECTOR = "##REPLACE_ON_INSTALL##/calico_route_reflector.sh"
+
+
+def _get_configured_compute_nodes():
+    with open(NODES_CONFIG, "r") as f:
+        config = yaml.safe_load(f)
+
+    compute_nodes = [node for node in config["nodes"]
+                     if node["role"] == "compute"]
+
+    return compute_nodes
+
+
+class DeploymentChangeHandler(pyinotify.ProcessEvent):
+    def __init__(self):
+        super(DeploymentChangeHandler, self).__init__()
+        self.compute_nodes = _get_configured_compute_nodes()
+
+    def process_IN_MODIFY(self, event):
+        current_compute_nodes = _get_configured_compute_nodes()
+        if current_compute_nodes != self.compute_nodes:
+            subprocess.call(RECONFIGURE_ROUTE_REFLECTOR)
+            self.compute_nodes = current_compute_nodes
+
+
+if __name__ == "__main__":
+    handler = DeploymentChangeHandler()
+    watch_manager = pyinotify.WatchManager()
+    notifier = pyinotify.Notifier(watch_manager, handler)
+    watch_manager.add_watch(NODES_CONFIG, pyinotify.IN_MODIFY)
+    notifier.loop()
+

deployment_scripts/calico_controller.sh

@@ -181,4 +181,41 @@ iptables -I INPUT 1 -p tcp --dport 179 -j ACCEPT
 # controller is rebooted.
 iptables-save > /etc/iptables/rules.v4
 
+# Set up a service, calico-fuel-monitor, that will detect changes to the
+# deployment and reconfigure the calico components on the controller as
+# needed. For example, updating the route reflector configuration after
+# compute nodes are added/removed from the deployment.
+SERVICE_NAME=calico-fuel-monitor
+
+# Install the service's dependencies.
+apt-get -y install python-pip
+pip install pyinotify pyaml
+
+# During node deployment, the plugin deployment scripts are copied into 
+# /etc/fuel/plugins/<plugin_name>-<plugin_version> on the node, and this
+# script is run from that directory.
+SERVICE_DIR=$(pwd)
+sed -i "s@##REPLACE_ON_INSTALL##@${SERVICE_DIR}@" $SERVICE_NAME
+chmod +x $SERVICE_NAME
+
+cat << SERVICE_CFG >> /etc/init/calico-fuel-monitor.conf
+# calico-fuel-monitor - daemon to monitor for fuel deployment changes and
+#                       reconfigure the calico components accordingly
+
+description "Calico daemon to monitor fuel deployment changes"
+author "Emma Gordon <emma@projectcalico.org>"
+
+start on runlevel [2345]
+stop on runlevel [016]
+
+respawn
+
+script
+cd ${SERVICE_DIR}
+exec ./${SERVICE_NAME}
+end script
+SERVICE_CFG
+
+service $SERVICE_NAME start
+
 exit 0

deployment_scripts/get_rr_peers.py

@@ -2,12 +2,11 @@
 # Copyright 2015 Metaswitch Networks
 
 import yaml
-from pluginutils import get_config_file_for_node_type
+
+from pluginutils import NODES_CONFIG
 
 def main():
-    config_file = get_config_file_for_node_type()
-
-    with open(config_file, "r") as f:
+    with open(NODES_CONFIG, "r") as f:
         config = yaml.safe_load(f)
 
     # The route reflector should only peer with compute nodes.

deployment_scripts/pluginutils.py

@@ -3,6 +3,15 @@
 
 import os
 
+# This config file is updated with the latest node details as the deployment
+# evolves. It only contains node details, not other config settings.
+NODES_CONFIG = "/etc/hiera/nodes.yaml"
+
+# These config files contain details of the nodes at initial deployment, but
+# they are not subsequently updated with node changes. However, they contain
+# a greater range of information, including settings and network config. They
+# are also created on the system earlier in the deployment process, so are
+# good sources of initial node information during Calico setup.
 PRIMARY_CONTROLLER_CFG = "/etc/primary-controller.yaml"
 CONTROLLER_CFG = "/etc/controller.yaml"
 COMPUTE_CFG = "/etc/compute.yaml"