From 2207bea6ebaf554a4efe76659bf2bb795883151d Mon Sep 17 00:00:00 2001
From: David Wilson <dw@botanicus.net>
Date: Tue, 2 Feb 2021 12:57:16 +0000
Subject: [PATCH] issue #754: support MITOGEN_UNIX_DIR environment variable

---
 ansible_mitogen/process.py |  5 ++++-
 docs/ansible_detailed.rst  | 12 ++++++++++++
 mitogen/unix.py            |  8 ++++++--
 3 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/ansible_mitogen/process.py b/ansible_mitogen/process.py
index 1fc7bf80..2d1a6358 100644
--- a/ansible_mitogen/process.py
+++ b/ansible_mitogen/process.py
@@ -627,7 +627,10 @@ class MuxProcess(object):
         #: MuxProcess CPU index.
         self.index = index
         #: Individual path of this process.
-        self.path = mitogen.unix.make_socket_path()
+        self.path = mitogen.unix.make_socket_path(
+            # issue #754: overlong temp paths may easily overflow sockaddr_un
+            dir=os.environ.get('MITOGEN_UNIX_DIR'),
+        )
 
     def start(self):
         self.pid = os.fork()
diff --git a/docs/ansible_detailed.rst b/docs/ansible_detailed.rst
index c9bbcf51..1dc1093d 100644
--- a/docs/ansible_detailed.rst
+++ b/docs/ansible_detailed.rst
@@ -515,6 +515,18 @@ In summary, for each task Ansible may create one or more of:
 * ``$TMPDIR/ansible_<modname>_payload_.../`` owned by the become user,
 * ``$TMPDIR/ansible-module-tmp-.../`` owned by the become user.
 
+Temporary Files (Controller)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+To create UNIX sockets used for inter-process communication on the Ansible
+controller host, Mitogen normally uses a temporary directory selected
+by the :mod:`tempfile` module, however is possible the selected directory
+cannot be used as its name its path exceeds the system-defined 108 byte limit
+on UNIX socket paths.
+
+In this case, the ``MITOGEN_UNIX_DIR`` environment variable may be used to
+define an alternative directory.
+
 
 Mitogen for Ansible
 ^^^^^^^^^^^^^^^^^^^
diff --git a/mitogen/unix.py b/mitogen/unix.py
index 1af1c0ec..a0c07ad4 100644
--- a/mitogen/unix.py
+++ b/mitogen/unix.py
@@ -79,8 +79,12 @@ def is_path_dead(path):
     return False
 
 
-def make_socket_path():
-    return tempfile.mktemp(prefix='mitogen_unix_', suffix='.sock')
+def make_socket_path(dir=None):
+    return tempfile.mktemp(
+        prefix='mitogen_unix_',
+        suffix='.sock',
+        dir=dir,
+    )
 
 
 class ListenerStream(mitogen.core.Stream):