add a label to turn on/off a service balanced in haproxy in swarm mode (#150)

* add a label to switch services on blue/green testing

* bump ver

Author: Feng Honglin

README.md

@@ -251,7 +251,14 @@ Settings here can overwrite the settings in HAProxy, which are only applied to t
 |TCP_PORTS|comma separated ports(e.g. 9000, 9001, 2222/ssl). The port listed in `TCP_PORTS` will be load-balanced in TCP mode. Port ends with `/ssl` indicates that port needs SSL termination.
 |VIRTUAL_HOST_WEIGHT|an integer of the weight of an virtual host, used together with `VIRTUAL_HOST`, default:0. It affects the order of acl rules of the virtual hosts. The higher weight one virtual host has, the more priority that acl rules applies.|
 |VIRTUAL_HOST|specify virtual host and virtual path. Format: `[scheme://]domain[:port][/path], ...`. wildcard `*` can be used in `domain` and `path` part|
-|SERVICE_PORTS|comma separated ports(e.g. 80, 8080), which are the ports you would like to expose in your application service. This envvar is swarm mode only, and it is **MUST** be set in swarm mode|
+
+Swarm Mode only settings:
+
+|Name|Type|Description|
+|:--:|:--:|:---------:|
+|SERVICE_PORTS|envvar|comma separated ports(e.g. 80, 8080), which are the ports you would like to expose in your application service. This envvar is swarm mode only, and it is **MUST** be set in swarm mode|
+|`com.docker.dockercloud.haproxy.deactivate=<true|false>`|label|when this label is set to true, haproxy will ignore the service. Could be useful for switching services on blue/green testing|
+
 
 Check [the HAProxy configuration manual](http://cbonte.github.io/haproxy-dconv/configuration-1.5.html) for more information on the above.
 

haproxy/__init__.py

@@ -1 +1 @@
-__version__ = "1.6.1"
+__version__ = "1.6.2"

haproxy/config.py

@@ -32,6 +32,7 @@ def parse_extra_frontend_settings(envvars):
                     settings_dict[port] = settings
     return settings_dict
 
+
 def parse_additional_backend_settings(envvars):
     settings_dict = {}
     if isinstance(envvars, os._Environ) or isinstance(envvars, dict):
@@ -47,6 +48,7 @@ def parse_additional_backend_settings(envvars):
                     settings_dict[server] = settings
     return settings_dict
 
+
 # envvar
 ADDITIONAL_BACKENDS = parse_additional_backend_settings(os.environ)
 ADDITIONAL_SERVICES = os.getenv("ADDITIONAL_SERVICES")
@@ -94,6 +96,7 @@ def parse_additional_backend_settings(envvars):
 API_RETRY = 10  # seconds
 PID_FILE = "/tmp/dockercloud-haproxy.pid"
 SERVICE_PORTS_ENVVAR_NAME = "SERVICE_PORTS"
+LABEL_SWARM_MODE_DEACTIVATE = "com.docker.dockercloud.haproxy.deactivate"
 
 # regular expressions
 SERVICE_NAME_MATCH = re.compile(r"(.+)_\d+$")

haproxy/eventhandler.py

@@ -9,6 +9,7 @@
 
 import config
 import helper.cloud_mode_link_helper
+import helper.swarm_mode_link_helper as SwarmModeLinkHelper
 from haproxycfg import add_haproxy_run_task, Haproxy
 from utils import get_uuid_from_resource_uri
 
@@ -106,17 +107,11 @@ def polling_service_status_swarm_mode():
             except:
                 docker = docker_client(os.environ)
 
+            services = docker.services()
             tasks = docker.tasks(filters={"desired-state": "running"})
-            linked_tasks = set()
-            for task in tasks:
-                task_nets = [network.get("Network", {}).get("ID", "") for network in
-                             task.get("NetworksAttachments", [])]
-                task_service_id = task.get("ServiceID", "")
-                if task_service_id != Haproxy.cls_service_id and Haproxy.cls_nets.intersection(set(task_nets)):
-                    task_id = task.get("ID", "")
-                    linked_tasks.add(task_id)
-
-            if Haproxy.cls_linked_tasks != linked_tasks:
+            _, linked_tasks = SwarmModeLinkHelper.get_task_links(tasks, services, Haproxy.cls_service_id,
+                                                                 Haproxy.cls_nets)
+            if cmp(Haproxy.cls_linked_tasks, linked_tasks) != 0:
                 add_haproxy_run_task("Tasks are updated")
         except APIError as e:
             logger.info("Docker API error: %s" % e)

haproxy/haproxycfg.py

@@ -395,4 +395,4 @@ def _config_adittional_backends_sections(self):
             for key in ADDITIONAL_BACKENDS:
                 cfg["backend %s" % key] = ADDITIONAL_BACKENDS[key]
 
-        return cfg
+        return cfg

haproxy/helper/backend_helper.py

@@ -45,6 +45,7 @@ def get_backend_routes(route_setting, is_sticky, routes, routes_added, service_a
 
     return sorted(backend_routes)
 
+
 def get_route_health_check(details, service_alias, default_health_check):
     health_check = get_service_attribute(details, "health_check", service_alias)
     health_check = health_check if health_check else default_health_check

haproxy/helper/swarm_mode_link_helper.py

@@ -1,7 +1,7 @@
 import logging
 
 import compose_mode_link_helper
-from haproxy.config import SERVICE_PORTS_ENVVAR_NAME
+from haproxy.config import SERVICE_PORTS_ENVVAR_NAME, LABEL_SWARM_MODE_DEACTIVATE
 
 logger = logging.getLogger("haproxy")
 
@@ -27,14 +27,14 @@ def get_swarm_mode_haproxy_id_nets(docker, haproxy_container_short_id):
 def get_swarm_mode_links(docker, haproxy_service_id, haproxy_nets):
     services = docker.services()
     tasks = docker.tasks(filters={"desired-state": "running"})
-    links, linked_tasks = get_task_links(tasks, services, haproxy_service_id, haproxy_nets)
-    return links, linked_tasks
+    return get_task_links(tasks, services, haproxy_service_id, haproxy_nets)
 
 
 def get_task_links(tasks, services, haproxy_service_id, haproxy_nets):
     services_id_name = {s.get("ID"): s.get("Spec", {}).get("Name", "") for s in services}
+    services_id_labels = {s.get("ID"): s.get("Spec", {}).get("Labels", {}) for s in services}
     links = {}
-    linked_tasks = set()
+    linked_tasks = {}
     for task in tasks:
         task_nets = [network.get("Network", {}).get("ID", "") for network in task.get("NetworksAttachments", [])]
         task_service_id = task.get("ServiceID", "")
@@ -44,6 +44,11 @@ def get_task_links(tasks, services, haproxy_service_id, haproxy_nets):
             task_slot = "%d" % task.get("Slot", 0)
             task_service_id = task.get("ServiceID", "")
             task_service_name = services_id_name.get(task_service_id, "")
+            task_labels = services_id_labels.get(task_service_id)
+
+            if task_labels.get(LABEL_SWARM_MODE_DEACTIVATE, "").lower() == "true":
+                continue
+
             container_name = ".".join([task_service_name, task_slot, task_id])
             task_envvars = get_task_envvars(task.get("Spec", {}).get("ContainerSpec", {}).get("Env", []))
 
@@ -68,7 +73,7 @@ def get_task_links(tasks, services, haproxy_service_id, haproxy_nets):
 
             links[task_id] = {"endpoints": task_endpoints, "container_name": container_name,
                               "service_name": task_service_name, "container_envvars": task_envvars}
-            linked_tasks.add(task_id)
+            linked_tasks[task_id] = task_labels
     return links, linked_tasks
 
 

tests/unit/helper/test_swarm_mode_link_helper.py

@@ -913,7 +913,8 @@
     u'31b6fuwub6dcgdrvy0kivxvug': {'service_name': u'app', 'endpoints': {u'80/tcp': u'tcp://10.0.0.7:80'},
                                    'container_envvars': [{'value': u'80', 'key': u'SERVICE_PORTS'}],
                                    'container_name': u'app.3.31b6fuwub6dcgdrvy0kivxvug'}}
-expected_linked_tasks = {u'7y45xdhy929wzcq94wqdqb8d3', u'bbref0yvjbix87pv6xz1jc3pr', u'31b6fuwub6dcgdrvy0kivxvug'}
+expected_linked_tasks = {u'7y45xdhy929wzcq94wqdqb8d3':{}, u'bbref0yvjbix87pv6xz1jc3pr':{},
+                         u'31b6fuwub6dcgdrvy0kivxvug':{}}
 expected_nets = {"b951j4at14qali5nxevshec93", "0l130ctu8xay6vfft1mb4tjv0"}
 expected_service_id = "07ql4q5a48seh1uhcr2m7ngar"
 
@@ -944,7 +945,6 @@ def services(self):
 
             def tasks(self, filters):
                 return [t for t in tasks if t.get("DesiredState", "") == "running"]
-
         links, linked_tasks = get_swarm_mode_links(Docker(), expected_service_id, expected_nets)
         self.assertEquals(expected_links, links)
         self.assertEquals(expected_linked_tasks, linked_tasks)