haproxy: Enable/disable health and agent checks (#689)

* Enable/disable health and agent checks

Health and agent checks can cause a disabled service to re-enable
itself.  This adds "health" and "agent" options that will also
enable or disable those checks, matching if the service is to be
enabled/disabled.

* Update plugins/modules/net_tools/haproxy.py

Co-authored-by: Felix Fontein <felix@fontein.de>

* Update plugins/modules/net_tools/haproxy.py

Co-authored-by: Felix Fontein <felix@fontein.de>

* Update plugins/modules/net_tools/haproxy.py

Co-authored-by: Felix Fontein <felix@fontein.de>

* Update plugins/modules/net_tools/haproxy.py

Co-authored-by: Felix Fontein <felix@fontein.de>

* Changes to documentation and changelog.

Changes for the haproxy documentation to resolve issues with
the CI/CD, and adding a changelog fragment.

* Update changelogs/fragments/689-haproxy_agent_and_health.yml

Co-authored-by: Felix Fontein <felix@fontein.de>

* Update changelogs/fragments/689-haproxy_agent_and_health.yml

Co-authored-by: Felix Fontein <felix@fontein.de>

* Update plugins/modules/net_tools/haproxy.py

Co-authored-by: Felix Fontein <felix@fontein.de>

* Add an example of health/agent disable.

* Update plugins/modules/net_tools/haproxy.py

Co-authored-by: Andrew Klychkov <aaklychkov@mail.ru>

Co-authored-by: Felix Fontein <felix@fontein.de>
Co-authored-by: Andrew Klychkov <aaklychkov@mail.ru>

changelogs/fragments/689-haproxy_agent_and_health.yml

@@ -0,0 +1,7 @@
+---
+minor_changes:
+  - haproxy - add options to dis/enable health and agent checks.  When health
+    and agent checks are enabled for a service, a disabled service will
+    re-enable itself automatically.  These options also change the state of
+    the agent checks to match the requested state for the backend
+    (https://github.com/ansible-collections/community.general/issues/684).

plugins/modules/net_tools/haproxy.py

@@ -62,6 +62,18 @@ options:
     type: str
     required: true
     choices: [ disabled, drain, enabled ]
+  agent:
+    description:
+      - Disable/enable agent checks (depending on I(state) value).
+    type: bool
+    default: no
+    version_added: 1.0.0
+  health:
+    description:
+      - Disable/enable health checks (depending on I(state) value).
+    type: bool
+    default: no
+    version_added: "1.0.0"
   fail_on_not_found:
     description:
       - Fail whenever trying to enable/disable a backend host that does not exist
@@ -100,6 +112,13 @@ EXAMPLES = r'''
     host: '{{ inventory_hostname }}'
     backend: www
 
+- name: Disable server in 'www' backend pool, also stop health/agent checks
+  community.general.haproxy:
+    state: disabled
+    host: '{{ inventory_hostname }}'
+    health: yes
+    agent: yes
+
 - name: Disable server without backend pool name (apply to all available backend pool)
   community.general.haproxy:
     state: disabled
@@ -228,6 +247,8 @@ class HAProxy(object):
         self.socket = self.module.params['socket']
         self.shutdown_sessions = self.module.params['shutdown_sessions']
         self.fail_on_not_found = self.module.params['fail_on_not_found']
+        self.agent = self.module.params['agent']
+        self.health = self.module.params['health']
         self.wait = self.module.params['wait']
         self.wait_retries = self.module.params['wait_retries']
         self.wait_interval = self.module.params['wait_interval']
@@ -360,6 +381,10 @@ class HAProxy(object):
         set the weight for haproxy backend server when provides.
         """
         cmd = "get weight $pxname/$svname; enable server $pxname/$svname"
+        if self.agent:
+            cmd += "; enable agent $pxname/$svname"
+        if self.health:
+            cmd += "; enable health $pxname/$svname"
         if weight:
             cmd += "; set weight $pxname/$svname %s" % weight
         self.execute_for_backends(cmd, backend, host, 'UP')
@@ -370,7 +395,12 @@ class HAProxy(object):
         performed on the server until it leaves maintenance,
         also it shutdown sessions while disabling backend host server.
         """
-        cmd = "get weight $pxname/$svname; disable server $pxname/$svname"
+        cmd = "get weight $pxname/$svname"
+        if self.agent:
+            cmd += "; disable agent $pxname/$svname"
+        if self.health:
+            cmd += "; disable health $pxname/$svname"
+        cmd += "; disable server $pxname/$svname"
         if shutdown_sessions:
             cmd += "; shutdown sessions server $pxname/$svname"
         self.execute_for_backends(cmd, backend, host, 'MAINT')
@@ -428,6 +458,8 @@ def main():
             socket=dict(type='path', default=DEFAULT_SOCKET_LOCATION),
             shutdown_sessions=dict(type='bool', default=False),
             fail_on_not_found=dict(type='bool', default=False),
+            health=dict(type='bool', default=False),
+            agent=dict(type='bool', default=False),
             wait=dict(type='bool', default=False),
             wait_retries=dict(type='int', default=WAIT_RETRIES),
             wait_interval=dict(type='int', default=WAIT_INTERVAL),