From 6e039352803f96576bf91a2086986c7a2daad99f Mon Sep 17 00:00:00 2001
From: David Wilson <dw@botanicus.net>
Date: Sun, 19 May 2019 13:12:41 +0100
Subject: [PATCH 1/2] issue #587: ansible: descriptive version check during
 startup.

---
 ansible_mitogen/strategy.py | 39 +++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/ansible_mitogen/strategy.py b/ansible_mitogen/strategy.py
index ba0ff5251..b9211fcc0 100644
--- a/ansible_mitogen/strategy.py
+++ b/ansible_mitogen/strategy.py
@@ -37,9 +37,46 @@
 import ansible_mitogen.mixins
 import ansible_mitogen.process
 
+import ansible
 import ansible.executor.process.worker
 
 
+ANSIBLE_VERSION_MIN = '2.3'
+ANSIBLE_VERSION_MAX = '2.7'
+NEW_VERSION_MSG = (
+    "Your Ansible version (%s) is too recent. The most recent version\n"
+    "supported by Mitogen for Ansible is %s.x. Please check the Mitogen\n"
+    "release notes to see if a new version is available, otherwise\n"
+    "subscribe to the corresponding GitHub issue to be notified when\n"
+    "support becomes available.\n"
+    "\n"
+    "    https://mitogen.rtfd.io/en/latest/changelog.html\n"
+    "    https://github.com/dw/mitogen/issues/\n"
+)
+OLD_VERSION_MSG = (
+    "Your version of Ansible (%s) is too old. The oldest version supported by "
+    "Mitogen for Ansible is %s."
+)
+
+
+def _assert_supported_release():
+    """
+    Throw AnsibleError with a descriptive message in case of being loaded into
+    an unsupported Ansible release.
+    """
+    v = ansible.__version__
+
+    if v[:len(ANSIBLE_VERSION_MIN)] < ANSIBLE_VERSION_MIN:
+        raise ansible.errors.AnsibleError(
+            OLD_VERSION_MSG % (v, ANSIBLE_VERSION_MIN)
+        )
+
+    if v[:len(ANSIBLE_VERSION_MAX)] > ANSIBLE_VERSION_MAX:
+        raise ansible.errors.AnsibleError(
+            NEW_VERSION_MSG % (ansible.__version__, ANSIBLE_VERSION_MAX)
+        )
+
+
 def _patch_awx_callback():
     """
     issue #400: AWX loads a display callback that suffers from thread-safety
@@ -245,6 +282,8 @@ def run(self, iterator, play_context, result=0):
         Arrange for a mitogen.master.Router to be available for the duration of
         the strategy's real run() method.
         """
+        _assert_supported_release()
+
         ansible_mitogen.process.MuxProcess.start()
         run = super(StrategyMixin, self).run
         self._add_plugin_paths()

From 0b110305c9fa16e2416aecf3abed09a0104e3dcf Mon Sep 17 00:00:00 2001
From: David Wilson <dw@botanicus.net>
Date: Sun, 19 May 2019 13:20:24 +0100
Subject: [PATCH 2/2] issue #587: update Changelog

---
 docs/changelog.rst | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/docs/changelog.rst b/docs/changelog.rst
index e8ee19b42..c09533855 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -44,6 +44,10 @@ Fixes
   the username, hostname and process ID of ``ansible-playbook`` running on the
   controller machine.
 
+* `#587 <https://github.com/dw/mitogen/issues/587>`_: display a friendly
+  message when running on an unsupported version of Ansible, to cope with
+  potential influx of 2.8-related bug reports.
+
 
 Thanks!
 ~~~~~~~