Merge remote-tracking branch 'origin/dmw'

* origin/dmw:
  docs: update Changelog; closes #481
  issue #481: core: preserve stderr TTY FD if one is present.
  issue #481: avoid crash if disconnect occurs during forward_modules()
  Add a few more important modules to preamble_size.py.
  .ci: add verbiage for run_batches() too.
  .ci: add README.md.
  docs: update thanks
  docs: lose "approaching stability" language, we're pretty good now
  docs: fix changelog syntax/order/"20KB"

.ci/README.md

@@ -0,0 +1,44 @@
+
+# `.ci`
+
+This directory contains scripts for Travis CI and (more or less) Azure
+Pipelines, but they will also happily run on any Debian-like machine.
+
+The scripts are usually split into `_install` and `_test` steps. The `_install`
+step will damage your machine, the `_test` step will just run the tests the way
+CI runs them.
+
+There is a common library, `ci_lib.py`, which just centralized a bunch of
+random macros and also environment parsing.
+
+Some of the scripts allow you to pass extra flags through to the component
+under test, e.g. `../../.ci/ansible_tests.py -vvv` will run with verbose.
+
+Hack these scripts until your heart is content. There is no pride to be found
+here, just necessity.
+
+
+### `ci_lib.run_batches()`
+
+There are some weird looking functions to extract more paralellism from the
+build. The above function takes lists of strings, arranging for the strings in
+each list to run in order, but for the lists to run in parallel. That's great
+for doing `setup.py install` while pulling a Docker container, for example.
+
+
+### Environment Variables
+
+* `VER`: Ansible version the `_install` script should install. Default changes
+  over time.
+* `TARGET_COUNT`: number of targets for `debops_` run. Defaults to 2.
+* `DISTRO`: the `mitogen_` tests need a target Docker container distro. This
+  name comes from the Docker Hub `mitogen` user, i.e. `mitogen/$DISTRO-test`
+* `DISTROS`: the `ansible_` tests can run against multiple targets
+  simultaneously, which speeds things up. This is a space-separated list of
+  DISTRO names, but additionally, supports:
+    * `debian-py3`: when generating Ansible inventory file, set
+      `ansible_python_interpreter` to `python3`, i.e. run a test where the
+      target interpreter is Python 3.
+    * `debian*16`: generate 16 Docker containers running Debian. Also works
+      with -py3.
+

docs/ansible.rst

@@ -10,9 +10,8 @@ Mitogen, replacing embedded shell invocations with pure-Python equivalents
 invoked via highly efficient remote procedure calls to persistent interpreters
 tunnelled over SSH. No changes are required to target hosts.
 
-The extension is approaching stability and real-world usage is encouraged. `Bug
-reports`_ are welcome: Ansible is huge, and only wide testing will ensure
-soundness.
+The extension is stable and real-world use is encouraged. `Bug reports`_ are
+welcome: Ansible is huge, and only wide testing will ensure soundness.
 
 .. _Ansible: https://www.ansible.com/
 

docs/changelog.rst

@@ -455,6 +455,21 @@ Core Library
   import :mod:`__main__` on Python 3.4 and newer due to a breaking change in
   the :mod:`pkgutil` API. The program's main script is now handled specially.
 
+* `#481 <https://github.com/dw/mitogen/issues/481>`_: the version of `sudo`
+  that shipped with CentOS 5 replaced itself with the program to be executed,
+  and therefore did not hold any child PTY open on our behalf. The child
+  context is updated to preserve any PTY FD in order to avoid the kernel
+  sending `SIGHUP` early during startup.
+
+* `#523 <https://github.com/dw/mitogen/issues/523>`_: the test suite didn't
+  generate a code coverage report if any test failed.
+
+* `#524 <https://github.com/dw/mitogen/issues/524>`_: Python 3.6+ emitted a
+  :class:`DeprecationWarning` for :func:`mitogen.utils.run_with_router`.
+
+* `#529 <https://github.com/dw/mitogen/issues/529>`_: Code coverage of the
+  test suite was not measured across all Python versions.
+
 * `16ca111e <https://github.com/dw/mitogen/commit/16ca111e>`_: handle OpenSSH
   7.5 permission denied prompts when ``~/.ssh/config`` rewrites are present.
 
@@ -475,18 +490,9 @@ Core Library
   a failure.
 
 * `57b652ed <https://github.com/dw/mitogen/commit/57b652ed>`_: a stray import
-  meant an extra roundtrip and ~20KiB of data was wasted for any context that
+  meant an extra roundtrip and ~4KiB of data was wasted for any context that
   imported :mod:`mitogen.parent`.
 
-* `#523 <https://github.com/dw/mitogen/issues/523>` : the test suite didn't
-  generate a code coverage report if any test failed.
-
-* `#524 <https://github.com/dw/mitogen/issues/524>` : Python 3.6+ emitted a
-  :class:`DeprecationWarning` for :func:`mitogen.utils.run_with_router`.
-
-* `#529 <https://github.com/dw/mitogen/issues/529>` : Code coverage of the
-  test suite was not measured across all Python versions.
-
 
 Thanks!
 ~~~~~~~
@@ -508,6 +514,7 @@ bug reports, testing, features and fixes in this release contributed by
 `Johan Beisser <https://github.com/jbeisser>`_,
 `Jonathan Rosser <https://github.com/jrosser>`_,
 `Josh Smift <https://github.com/jbscare>`_,
+`Kevin Carter <https://github.com/cloudnull>`_,
 `Mehdi <https://github.com/mehdisat7>`_,
 `Michael DeHaan <https://github.com/mpdehaan>`_,
 `Michal Medvecky <https://github.com/michalmedvecky>`_,

mitogen/core.py

@@ -3295,6 +3295,18 @@ class ExternalContext(object):
                 os.close(fd)
 
     def _setup_stdio(self):
+        # #481: when stderr is a TTY due to being started via
+        # tty_create_child()/hybrid_tty_create_child(), and some privilege
+        # escalation tool like prehistoric versions of sudo exec this process
+        # over the top of itself, there is nothing left to keep the slave PTY
+        # open after we replace our stdio. Therefore if stderr is a TTY, keep
+        # around a permanent dup() to avoid receiving SIGHUP.
+        try:
+            if os.isatty(2):
+                self.reserve_tty_fd = os.dup(2)
+                set_cloexec(self.reserve_tty_fd)
+        except OSError:
+            pass
         # When sys.stdout was opened by the runtime, overwriting it will not
         # close FD 1. However when forking from a child that previously used
         # fdopen(), overwriting it /will/ close FD 1. So we must swallow the

mitogen/master.py

@@ -922,6 +922,11 @@ class ModuleResponder(object):
             fullname, _, _ = str_rpartition(fullname, u'.')
 
         stream = self._router.stream_by_id(context.context_id)
+        if stream is None:
+            LOG.debug('%r: dropping forward of %s to no longer existent '
+                      '%r', self, path[0], context)
+            return
+
         for fullname in reversed(path):
             self._send_module_and_related(stream, fullname)
             self._send_forward_module(stream, context, fullname)

preamble_size.py

@@ -16,6 +16,9 @@ import mitogen.service
 import mitogen.ssh
 import mitogen.sudo
 
+import ansible_mitogen.runner
+import ansible_mitogen.target
+
 router = mitogen.master.Router()
 context = mitogen.parent.Context(router, 0)
 stream = mitogen.ssh.Stream(router, 0, max_message_size=0, hostname='foo')
@@ -31,7 +34,7 @@ if '--dump' in sys.argv:
 
 
 print(
-    '               '
+    '                           '
     ' '
     '  Original   '
     '  '
@@ -42,6 +45,9 @@ print(
 
 for mod in (
         mitogen.parent,
+        mitogen.fork,
+        ansible_mitogen.target,
+        ansible_mitogen.runner,
         mitogen.ssh,
         mitogen.sudo,
         mitogen.select,
@@ -56,7 +62,7 @@ for mod in (
     compressed = zlib.compress(minimized, 9)
     compressed_size = len(compressed)
     print(
-        '%-15s'
+        '%-25s'
         ' '
         '%5i %4.1fKiB'
         '  '

tests/responder_test.py

@@ -167,6 +167,19 @@ class BrokenModulesTest(testlib.TestCase):
 
 
 class ForwardTest(testlib.RouterMixin, testlib.TestCase):
+    def test_forward_to_nonexistent_context(self):
+        nonexistent = mitogen.core.Context(self.router, 123)
+        capture = testlib.LogCapturer()
+        capture.start()
+        self.broker.defer_sync(lambda:
+            self.router.responder.forward_modules(
+                nonexistent,
+                ['mitogen.core']
+            )
+        )
+        s = capture.stop()
+        self.assertTrue('dropping forward of' in s)
+
     def test_stats(self):
         # Forwarding stats broken because forwarding is broken. See #469.
         c1 = self.router.local()