Add host index

README.md

   --etcd-host (default: etcd) hostname where ectd is running
   --etcd-port (default: 2379) port to connect to ectd on
   --etcd-prefix (default: /docker) prefix to write keys to
-  --name (default: docker) name of the host running docker
+  --name (default: unknown) name of the host running docker
 ```
 
 ## Schema
 
-The script stores values relating to containers, labels, and
+The script stores values relating to containers, labels, hosts and
 networks in etcd:
 
 ```
-/docker/containers/{name}/image = "ubuntu:xenial"
-                         /labels/service = "foo"
-                         /labels/org.example.some-label = "bar"
-                         /net/addr/{network1} = "172.1.2.3"
-                                  /{network2} = "172.0.2.3"
-                             /ports/tcp/{container_port1} = {host_port} 
-                                       /{container_port2} = 0 # Not exposed
-                                   /udp/...
-
-/docker/labels/{label_1}/{container_name_1} = "foo"
+/docker/containers/{name1}/host = "server1.example.com"
+                          /image = "ubuntu:xenial"
+                          /labels/service = "foo"
+                          /labels/org.example.some-label = "bar"
+                          /net/addr/{network1} = "172.1.2.3"
+                                   /{network2} = "172.0.2.3"
+                              /ports/tcp/{container_port1} = {host_port}
+                                        /{container_port2} = 0 # Not exposed
+                                    /udp/...
+                  /{name2}/...
+
+       /hosts/{host_1}/{container_name_1} = {container_name_1}
+                      /...
+             /{host_2}/...
+
+       /labels/{label_1}/{container_name_1} = "foo"
                         /{container_name_2} = "bar"
               /{label_2}/...
 
-/docker/networks/{network1}/{container_name_1} = "172.1.2.3"
+       /networks/{network1}/{container_name_1} = "172.1.2.3"
                            /{container_name_2} = "172.0.2.3"
                 /{network2}/...
 ```
 
 * The docker node is deleted when the script starts, so you can't run multiple
   copies on multiple hosts
-* The script updates once and exits, instead of listening for events
+* Containers that are stopped aren't removed 
 * There's no way to get notified when the script has finished, rather than
   mid-update
 

report.py

 
 
 def add_containers(infos):
-  global containers, label_index, network_index
+  global containers, host_index, label_index, network_index
   for info in infos:
     container = {
+      'host': host,
       'image': info['Image'],
       'labels': info['Labels'],
       'net': {
     for k, v in container['net']['addr'].items():
       network_index[k][name] = v
 
+    host_index[host][name] = name
+
+
+def write_all():
+  etcd_put(etcd_client, prefix + '/containers', containers)
+  etcd_put(etcd_client, prefix + '/labels', label_index)
+  etcd_put(etcd_client, prefix + '/networks', network_index)
+  etcd_put(etcd_client, prefix + '/hosts', host_index)
+
 
 parser = argparse.ArgumentParser()
 parser.add_argument('--name', help='Name of this docker host', default='unknown')
 docker_client = docker.Client(base_url='unix://var/run/docker.sock')
 etcd_client = etcd.Client(host=args.etcd_host, port=args.etcd_port)
 prefix = args.etcd_prefix
+host = args.name
 
 event_gen = docker_client.events(decode=True, filters={'type': 'container', 'event': ['die', 'start']})
 
 containers = {}
 label_index = defaultdict(dict) 
 network_index = defaultdict(dict)
+host_index = defaultdict(dict)
 
 add_containers(docker_client.containers())
 
 except etcd.EtcdKeyNotFound:
   pass
 
-etcd_put(etcd_client, prefix + '/containers', containers)
-etcd_put(etcd_client, prefix + '/labels', label_index)
-etcd_put(etcd_client, prefix + '/networks', network_index)
+write_all()
 
 for event in event_gen:
   if event['Action'] == 'start':
     print('New container %s' % event['id'])
     add_containers(docker_client.containers(filters={'id': event['id']}))
+    write_all()
   elif event['Action'] == 'die':
     print('Dead container %s' % event['id'])
   else: