add support for swarm mode

Author: tifayuki

README.md

@@ -17,11 +17,12 @@ The available version can be found here: https://hub.docker.com/r/dockercloud/ha
 
 You can use `dockercloud/haproxy` in three different ways:
 
-- running in Docker Cloud
-- running with Docker legacy links
-- running with Docker Compose v2 (new links, compatible with Docker Swarm)
+- running in Docker Cloud (Cloud Mode)
+- running with Docker legacy links (Legacy Mode)
+- running with Docker Compose v2 (Compose Mode, compatible with Docker Swarm)
+- running with Docker SwarmMode (Swarm Mode)
 
-### Running in Docker Cloud
+### Running in Docker Cloud (Cloud Mode)
 
 1. Launch the service you want to load-balance using Docker Cloud.
 
@@ -52,7 +53,28 @@ That's it - the haproxy container will start querying Docker Cloud's API for an
 	  roles:
 	    - global
 
-### Running with docker legacy links
+### Running with Docker SwarmMode (Swarm Mode)
+
+Docker 1.12 supports SwarmMode natively. `dockercloud/haproxy` will auto config itself to load balance all the services running on the same network:
+
+1. Create a new network using `docker create` command
+
+2. Launch `dockercloud/haproxy` service on that network
+
+3. Launch your application services that need to be load balanced on the same network.
+
+* If your application services need to access other services(database, for example), you can attach your application services to two different network, one is for database and the other one for the proxy
+* This feature is still experimental, please let us know if you find any bugs or have any suggestions.
+
+#### example of docker swarm mode support
+
+    docker network create -d overlay proxy
+    docker service create --name haproxy --network proxy --mount target=/var/run/docker.sock,source=/var/run/docker.sock,type=bind -p 80:80 dockercloud/haproxy
+    docker service create --name app --network proxy dockercloud/hello-world
+    docker service scale app=2
+    docker service update --env-add VIRTUAL_HOST=web.org app
+
+### Running with Docker legacy links (Legacy Mode)
 
 Legacy link refers to the link created before docker 1.10, and the link created in default bridge network in docker 1.10 or after.
 
@@ -79,7 +101,7 @@ Legacy link refers to the link created before docker 1.10, and the link created
 **Note**: Any link alias sharing the same prefix and followed by "-/_" with an integer is considered to be from the same service. For example: `web-1` and `web-2` belong to service `web`, `app_1` and `app_2` are from service `app`, but `app1` and `web2` are from different services.
 
 
-### Running with Docker Compose v2(new links)
+### Running with Docker Compose v2 (Compose Mode)
 
 Docker Compose 1.6 supports a new format of the compose file. In the new version(v2), the old link that injects environment variables is deprecated.
 

haproxy/config.py

@@ -2,6 +2,10 @@
 import re
 
 
+class RunningMode():
+    LegacyMode, ComposeMode, SwarmMode, CloudMode = range(4)
+
+
 def parse_extra_bind_settings(extra_bind_settings):
     bind_dict = {}
     if extra_bind_settings:
@@ -43,7 +47,7 @@ def parse_extra_frontend_settings(envvars):
 EXTRA_FRONTEND_SETTINGS = parse_extra_frontend_settings(os.environ)
 EXTRA_GLOBAL_SETTINGS = os.getenv("EXTRA_GLOBAL_SETTINGS")
 EXTRA_SSL_CERT = os.getenv("EXTRA_SSL_CERTS")
-EXTRA_ROUTE_SETTINGS=os.getenv("EXTRA_ROUTE_SETTINGS", "")
+EXTRA_ROUTE_SETTINGS = os.getenv("EXTRA_ROUTE_SETTINGS", "")
 HAPROXY_CONTAINER_URI = os.getenv("DOCKERCLOUD_CONTAINER_API_URI")
 HAPROXY_SERVICE_URI = os.getenv("DOCKERCLOUD_SERVICE_API_URI")
 HEALTH_CHECK = os.getenv("HEALTH_CHECK", "check inter 2000 rise 2 fall 3")
@@ -63,7 +67,7 @@ def parse_extra_frontend_settings(envvars):
 NBPROC = int(os.getenv("NBPROC", 1))
 
 # global
-LINK_MODE = ""
+RUNNING_MODE = None
 
 # const
 CERT_DIR = "/certs/"

haproxy/eventhandler.py

@@ -1,14 +1,14 @@
 import json
 import logging
-import time
 import os
+import time
 
 import dockercloud
 from compose.cli.docker_client import docker_client
 from docker.errors import APIError
 
 import config
-import helper.cloud_link_helper
+import helper.cloud_mode_link_helper
 from haproxycfg import add_haproxy_run_task, Haproxy
 from utils import get_uuid_from_resource_uri
 
@@ -38,7 +38,7 @@ def on_cloud_event(message):
 
 
 def on_websocket_open():
-    helper.cloud_link_helper.LINKED_CONTAINER_CACHE.clear()
+    helper.cloud_mode_link_helper.LINKED_CONTAINER_CACHE.clear()
     add_haproxy_run_task("Websocket open")
 
 
@@ -70,7 +70,7 @@ def listen_dockercloud_events():
             time.sleep(3600)
 
 
-def listen_docker_events():
+def listen_docker_events_compose_mode():
     while True:
         try:
             try:
@@ -81,7 +81,7 @@ def listen_docker_events():
             docker.ping()
             for event in docker.events(decode=True):
                 logger.debug(event)
-                attr = event.get("Actor", {}).get("Attributes")
+                attr = event.get("Actor", {}).get("Attributes", {})
                 compose_project = attr.get("com.docker.compose.project", "")
                 compose_service = attr.get("com.docker.compose.service", "")
                 container_name = attr.get("name", "")
@@ -95,3 +95,32 @@ def listen_docker_events():
 
         time.sleep(1)
         add_haproxy_run_task("Reconnect docker events")
+
+
+def listen_docker_events_swarm_mode():
+    while True:
+        try:
+            try:
+                docker = docker_client()
+            except:
+                docker = docker_client(os.environ)
+
+            docker.ping()
+            for event in docker.events(decode=True):
+                logger.debug(event)
+                action = event.get("Action", "")
+                type = event.get("Type", "")
+                container = event.get("Actor", {}).get("Attributes", {}).get("container", "")
+                network = event.get("Actor", {}).get("Attributes", {}).get("name")
+                id = event.get("Actor", {}).get("ID", "")
+                if type == "network" and action in ["connect", "disconnect"] and id in Haproxy.cls_swarm_networks:
+                    if action == "connect":
+                        msg = "Docker event: container %s %s to network %s" % (container, action, network)
+                    else:
+                        msg = "Docker event: container %s %s from network %s" % (container, action, network)
+                    add_haproxy_run_task(msg)
+        except APIError as e:
+            logger.info("Docker API error: %s" % e)
+
+        time.sleep(1)
+        add_haproxy_run_task("Reconnect docker events")

haproxy/haproxycfg.py

@@ -8,15 +8,16 @@
 
 import config
 import helper.backend_helper as BackendHelper
-import helper.cloud_link_helper as CloudLinkHelper
+import helper.cloud_mode_link_helper as CloudModeLinkHelper
+import helper.compose_mode_link_helper as ComposeModeLinkHelper
 import helper.config_helper as ConfigHelper
 import helper.frontend_helper as FrontendHelper
-import helper.new_link_helper as NewLinkHelper
 import helper.ssl_helper as SslHelper
+import helper.swarm_mode_link_helper as SwarmModeLinkHelper
 import helper.tcp_helper as TcpHelper
 import helper.update_helper as UpdateHelper
 from haproxy.config import *
-from haproxy.parser import LegacyLinkSpecs, NewLinkSpecs
+from haproxy.parser import LegacySpecs, NewSpecs
 from utils import fetch_remote_obj, prettify, save_to_file, get_service_attribute, get_bind_string
 
 logger = logging.getLogger("haproxy")
@@ -26,7 +27,7 @@
 
 def add_haproxy_run_task(msg=None):
     logger.info("=> Add task: %s", msg)
-    gevent.spawn(tasks.put, (config.LINK_MODE, msg))
+    gevent.spawn(tasks.put, (config.RUNNING_MODE, msg))
 
 
 def run_haproxy():
@@ -35,89 +36,118 @@ def run_haproxy():
         mode, msg = tasks.get()
         time.sleep(delay)
         while not tasks.empty():
-            if mode != "cloud":
+            if mode != RunningMode.CloudMode:
                 delay = 0.1
             logger.info("=> Task accumulated, skip: %s", msg)
             mode, msg = tasks.get()
             time.sleep(delay)
             continue
         logger.info("=> Executing task: %s", msg)
 
-        haproxy = Haproxy(config.LINK_MODE)
+        haproxy = Haproxy(config.RUNNING_MODE)
         haproxy.update()
 
 
 class Haproxy(object):
     cls_linked_services = set()
+    cls_swarm_networks = []
     cls_cfg = None
     cls_process = None
     cls_certs = []
     cls_ca_certs = []
 
-    def __init__(self, link_mode=""):
+    def __init__(self, running_mode=RunningMode.LegacyMode):
         logger.info("==========BEGIN==========")
-
-        self.link_mode = link_mode
+        self.running_mode = running_mode
         self.ssl_bind_string = None
         self.ssl_updated = False
         self.routes_added = []
         self.require_default_route = False
         self.specs = None
         self.tcp_ports = set()
-
-        self.specs = self._initialize(self.link_mode)
+        self.specs = self._initialize(self.running_mode)
 
     @staticmethod
-    def _initialize(link_mode):
-        if link_mode == "cloud":
+    def _initialize(running_mode):
+        if running_mode == RunningMode.CloudMode:
             links = Haproxy._init_cloud_links()
-            specs = NewLinkSpecs(links)
-        elif link_mode == "new":
-            links = Haproxy._init_new_links()
+            specs = NewSpecs(links)
+        elif running_mode == RunningMode.ComposeMode:
+            links = Haproxy._init_compose_mode_links()
+            if links is None:
+                specs = LegacySpecs()
+            else:
+                specs = NewSpecs(links)
+        elif running_mode == RunningMode.SwarmMode:
+            links = Haproxy._init_swarm_mode_links()
             if links is None:
-                specs = LegacyLinkSpecs()
+                specs = LegacySpecs()
             else:
-                specs = NewLinkSpecs(links)
+                specs = NewSpecs(links)
         else:
-            specs = LegacyLinkSpecs()
+            specs = LegacySpecs()
         return specs
 
     @staticmethod
     def _init_cloud_links():
         haproxy_container = fetch_remote_obj(HAPROXY_CONTAINER_URI)
         if haproxy_container:
-            links = CloudLinkHelper.get_cloud_links(haproxy_container)
-            Haproxy.cls_linked_services = CloudLinkHelper.get_linked_services(links)
-            logger.info("Linked service: %s", ", ".join(CloudLinkHelper.get_service_links_str(links)))
-            logger.info("Linked container: %s", ", ".join(CloudLinkHelper.get_container_links_str(links)))
+            links = CloudModeLinkHelper.get_cloud_mode_links(haproxy_container)
+            Haproxy.cls_linked_services = CloudModeLinkHelper.get_linked_services(links)
+            logger.info("Linked service: %s", ", ".join(CloudModeLinkHelper.get_service_links_str(links)))
+            logger.info("Linked container: %s", ", ".join(CloudModeLinkHelper.get_container_links_str(links)))
             return links
         else:
             return {}
 
     @staticmethod
-    def _init_new_links():
+    def _init_swarm_mode_links():
         try:
             try:
                 docker = docker_client()
             except:
                 docker = docker_client(os.environ)
 
             docker.ping()
+
+        except Exception as e:
+            logger.info("Docker API error, regressing to legacy links mode: %s" % e)
+            return None
+        haproxy_container_id = os.environ.get("HOSTNAME", "")
+        links, Haproxy.cls_linked_services, Haproxy.cls_swarm_networks = SwarmModeLinkHelper.get_swarm_mode_links(
+            docker, haproxy_container_id)
+        logger.info("Linked service: %s", ", ".join(SwarmModeLinkHelper.get_service_links_str(links)))
+        logger.info("Linked container: %s", ", ".join(SwarmModeLinkHelper.get_container_links_str(links)))
+        return links
+
+    @staticmethod
+    def _init_compose_mode_links():
+        try:
+            try:
+                docker = docker_client()
+            except:
+                docker = docker_client(os.environ)
+            docker.ping()
             container_id = os.environ.get("HOSTNAME", "")
             haproxy_container = docker.inspect_container(container_id)
         except Exception as e:
             logger.info("Docker API error, regressing to legacy links mode: %s" % e)
             return None
-        links, Haproxy.cls_linked_services = NewLinkHelper.get_new_links(docker, haproxy_container)
+        try:
+            links, Haproxy.cls_linked_services = ComposeModeLinkHelper.get_compose_mode_links(docker, haproxy_container)
+        except Exception as e:
+            logger.info("Docker API error, regressing to legacy links mode: %s" % e)
+            return None
 
         if ADDITIONAL_SERVICES:
-            additional_links, additional_services = NewLinkHelper.get_additional_links(docker, ADDITIONAL_SERVICES)
+            additional_links, additional_services = ComposeModeLinkHelper.get_additional_links(docker,
+                                                                                               ADDITIONAL_SERVICES)
             if additional_links and additional_services:
                 links.update(additional_links)
                 Haproxy.cls_linked_services.update(additional_services)
 
-        logger.info("Linked service: %s", ", ".join(NewLinkHelper.get_service_links_str(links)))
-        logger.info("Linked container: %s", ", ".join(NewLinkHelper.get_container_links_str(links)))
+        logger.info("Linked service: %s", ", ".join(ComposeModeLinkHelper.get_service_links_str(links)))
+        logger.info("Linked container: %s", ", ".join(ComposeModeLinkHelper.get_container_links_str(links)))
         return links
 
     def update(self):

haproxy/helper/cloud_link_helper.py haproxy/helper/cloud_mode_link_helper.pyhaproxy/helper/cloud_link_helper.py renamed to haproxy/helper/cloud_mode_link_helper.py

@@ -8,7 +8,7 @@
 pool = Pool(size=5)
 
 
-def get_cloud_links(haproxy_container):
+def get_cloud_mode_links(haproxy_container):
     links = _init_links(haproxy_container.linked_to_container)
     new_added_container_uris = _get_new_added_link_uri(LINKED_CONTAINER_CACHE, links)
     new_added_containers = _get_container_object_from_uri(new_added_container_uris)
@@ -69,7 +69,7 @@ def _get_linked_containers(cache, container_links):
 def get_linked_services(haproxy_links):
     linked_services = set()
     for link in haproxy_links.itervalues():
-            linked_services.add(link["service_uri"])
+        linked_services.add(link["service_uri"])
     return set(linked_services)