Added tool to capture L3 agent status

Change-Id: Ica6be14059dfd38662993265164817661d4a68d2

bindep.txt

@@ -0,0 +1,2 @@
+gcc [compile]
+libc-dev [compile]

openstack_tools/cmd/prometheus/routers_l3_ha.py

@@ -0,0 +1,80 @@
+# Copyright (c) 2020 CLOUD&HEAT GmbH https://www.cloudandheat.com
+# Copyright 2020 VEXXHOST, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Generate data for all routers and their L3 HA states.
+
+There are scenarios where an L3 HA router can end up being active in many
+different L3 agents.  This can be tricky to find and cause chaos in the system,
+while effort should be done in finding the root cause of this, this will help
+alert and catch any occurances of it.
+"""
+
+import argparse
+import glob
+import time
+import os
+
+import psutil
+
+
+def main():
+    """Entry-point for script."""
+
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--metric", default="node_openstack_l3_router_master",
+                        help="Name of metric")
+    parser.add_argument("--state", default="/var/lib/neutron",
+                        help="Neutron state path")
+    parser.add_argument("--loop", type=int, help="Loop every N seconds")
+    parser.add_argument("--output", help="Output file (default to STDOUT)")
+    args = parser.parse_args()
+
+    while True:
+        ha_conf_dir = os.path.join(args.state, 'ha_confs')
+        pid_glob = os.path.join(ha_conf_dir, '*.pid.keepalived-vrrp')
+        pid_files = glob.glob(pid_glob)
+
+        output = ""
+        for pid_file in pid_files:
+            with open(pid_file) as pid_fd:
+                pid = int(pid_fd.read())
+
+                # Check if the process is _actually_ running
+                if psutil.pid_exists(pid) is False:
+                    continue
+
+            state_path = pid_file.replace('.pid.keepalived-vrrp', '')
+            state_file = os.path.join(state_path, 'state')
+
+            router_id = os.path.basename(state_path)
+            with open(state_file) as state_fd:
+                master = 1 if 'master' in state_fd.read() else 0
+
+            output += '%s{router_id="%s"} %d\n' % (
+                args.metric,
+                router_id,
+                master
+            )
+
+        if args.output:
+            with open(args.output, 'w') as output_fd:
+                output_fd.write(output)
+
+        print(output)
+
+        if args.loop:
+            time.sleep(args.loop)
+        else:
+            break

requirements.txt

@@ -1 +1,2 @@
 ovs
+psutil

setup.cfg

@@ -25,4 +25,5 @@ packages =
 
 [entry_points]
 console_scripts =
+    openstack-prometheus-routers-l3-ha = openstack_tools.cmd.prometheus.routers_l3_ha:main
     openstack-cleanup-openvswitch = openstack_tools.cmd.cleanup.openvswitch:main