Use single-threaded WSGI server and fix mqissues

Dockerfile

@@ -7,8 +7,6 @@ RUN apk --no-cache add gcc musl-dev && \
 
 RUN mkdir -p /opt/plugin /run/docker/plugins /var/run/docker/netns
 COPY net-dhcp/ /opt/plugin/net_dhcp
-COPY plugin.sh /opt/plugin/launch.sh
 
 WORKDIR /opt/plugin
-ENV GUNICORN_OPTS="--log-level=DEBUG"
-ENTRYPOINT [ "/opt/plugin/launch.sh" ]
+ENTRYPOINT ["python", "-m", "net_dhcp"]

config.json

@@ -6,7 +6,7 @@
             "docker.networkdriver/1.0"
         ]
     },
-    "entrypoint": [ "/opt/plugin/launch.sh" ],
+    "entrypoint": [ "python", "-m", "net_dhcp" ],
     "workdir": "/opt/plugin",
     "network": {
         "type": "host"
@@ -25,16 +25,8 @@
     "linux": {
         "capabilities": [
             "CAP_NET_ADMIN",
-            "CAP_SYS_ADMIN"
+            "CAP_SYS_ADMIN",
+            "CAP_SYS_PTRACE"
         ]
-    },
-    "env": [
-        {
-            "name": "GUNICORN_OPTS",
-            "settable": [
-                "value"
-            ],
-            "value": "--log-level DEBUG --log-file /var/log/net-dhcp.log"
-        }
-    ]
+    }
 }

net-dhcp/__main__.py

@@ -0,0 +1,14 @@
+import logging
+import socketserver
+from werkzeug.serving import run_simple
+from . import app
+
+fh = logging.FileHandler('/var/log/net-dhcp.log')
+fh.setFormatter(logging.Formatter('%(asctime)s [%(levelname)s] %(message)s'))
+
+logger = logging.getLogger('net-dhcp')
+logger.setLevel(logging.DEBUG)
+logger.addHandler(fh)
+
+socketserver.TCPServer.allow_reuse_address = True
+run_simple('unix:///run/docker/plugins/net-dhcp.sock', 0, app)

net-dhcp/network.py

@@ -18,7 +18,7 @@ OPTS_KEY = 'com.docker.network.generic'
 OPT_BRIDGE = 'bridge'
 OPT_IPV6 = 'ipv6'
 
-logger = logging.getLogger('gunicorn.error')
+logger = logging.getLogger('net-dhcp')
 
 ndb = pyroute2.NDB()
 @atexit.register
@@ -147,6 +147,7 @@ def create_endpoint():
                 .set('state', 'up')
                 .commit())
 
+    time.sleep(0.5)
     if_container = (ndb.interfaces[if_container]
                     .set('state', 'up')
                     .commit())
@@ -372,14 +373,16 @@ class ContainerDHCPManager:
         if not self.dhcp:
             return
 
-        logger.info('Shutting down DHCPv4 client on %s in container namespace %s', \
-            self.dhcp.iface['ifname'], self.dhcp.netns)
-        self.dhcp.finish(timeout=1)
-
-        if self.ipv6:
-            logger.info('Shutting down DHCPv6 client on %s in container namespace %s', \
-                self.dhcp6.iface['ifname'], self.dhcp.netns)
-            self.dhcp6.finish(timeout=1)
-
-        ndb.sources.remove(self.dhcp.netns)
-        self._thread.join()
+        try:
+            logger.info('Shutting down DHCPv4 client on %s in container namespace %s', \
+                self.dhcp.iface['ifname'], self.dhcp.netns)
+            self.dhcp.finish(timeout=1)
+        finally:
+            try:
+                if self.ipv6:
+                    logger.info('Shutting down DHCPv6 client on %s in container namespace %s', \
+                        self.dhcp6.iface['ifname'], self.dhcp.netns)
+                    self.dhcp6.finish(timeout=1)
+            finally:
+                ndb.sources.remove(self.dhcp.netns)
+                self._thread.join()

net-dhcp/udhcpc.py

@@ -24,7 +24,7 @@ class EventType(Enum):
     DECONFIG = 'deconfig'
     LEASEFAIL = 'leasefail'
 
-logger = logging.getLogger('gunicorn.error')
+logger = logging.getLogger('net-dhcp')
 
 class DHCPClientError(Exception):
     pass
@@ -66,7 +66,7 @@ class DHCPClient:
 
         self._suffix = '6' if v6 else ''
         self._event_queue = posix_ipc.MessageQueue(f'/udhcpc{self._suffix}_{iface["address"].replace(":", "_")}', \
-            flags=os.O_CREAT | os.O_EXCL)
+            flags=os.O_CREAT | os.O_EXCL, max_messages=2, max_message_size=1024)
         self.proc = Popen(cmdline, env={'EVENT_QUEUE': self._event_queue.name})
         if hostname:
             logger.debug('[udhcpc%s#%d] using hostname "%s"', self._suffix, self.proc.pid, hostname)
@@ -77,6 +77,7 @@ class DHCPClient:
         self.domain = None
 
         self._shutdown_event = EventFD()
+        self.shutdown = False
         self._event_thread = threading.Thread(target=self._read_events)
         self._event_thread.start()
 
@@ -115,6 +116,8 @@ class DHCPClient:
                     listener(self, event['type'], event)
                 except Exception as ex:
                     logger.exception(ex)
+        self.shutdown = True
+        del self._shutdown_event
 
     def await_ip(self, timeout=10):
         if not self._has_lease.wait(timeout=timeout):
@@ -123,7 +126,7 @@ class DHCPClient:
         return self.ip
 
     def finish(self, timeout=5):
-        if self._shutdown_event.is_set():
+        if self.shutdown or self._shutdown_event.is_set():
             return
 
         try:

plugin.sh

@@ -1,2 +0,0 @@
-#!/bin/sh
-exec gunicorn $GUNICORN_OPTS --workers 1 --bind unix:/run/docker/plugins/net-dhcp.sock net_dhcp:app

requirements.txt

@@ -1,5 +1,4 @@
 flask==1.1.1
-gunicorn==19.9.0
 pyroute2==0.5.6
 docker==4.0.2
 eventfd==0.2