.. _changelog: Release Notes ============= .. raw:: html v0.2.8 (unreleased) ------------------- To avail of fixes in an unreleased version, please download a ZIP file `directly from GitHub `_. Enhancements ^^^^^^^^^^^^ * `#556 `_, `#587 `_: Ansible 2.8 is partially supported. `Become plugins `_ and `interpreter discovery `_ are not yet handled. * The ``MITOGEN_CPU_COUNT`` environment variable shards the connection multiplexer into per-CPU workers. This improves throughput for large runs especially involving file transfer, and is a prerequisite for future in-process SSH support. One multiplexer starts by default, to match existing behaviour. * `#419 `_, `#470 `_, file descriptor usage during large runs is halved, as it is no longer necessary to manage read and write sides distinctly in order to work around a design limitation. * `#419 `_: almost all connection setup happens on one thread, reducing GIL contention and context switching early in a run. * `#419 `_: Connection setup is pipelined, eliminating several network round-trips. Most infrastructure is in place to support future removal of the final round-trip between a target fully booting and receiving its first function call. * `d6faff06 `_, `807cbef9 `_, `e93762b3 `_, `50bfe4c7 `_: locking is avoided on hot paths, and some locks are released earlier, before waking a thread that must immediately take the same lock. Mitogen for Ansible ^^^^^^^^^^^^^^^^^^^ * `#363 `_: fix an obscure race matching *Permission denied* errors from some versions of ``su`` running on heavily loaded machines. * `#410 `_: Use of ``AF_UNIX`` sockets automatically replaced with plain UNIX pipes when SELinux is detected, to work around a broken heuristic in popular SELinux policies that prevents inheriting ``AF_UNIX`` sockets across privilege domains. * `#467 `_: an incompatibility running Mitogen under Molecule was resolved. * `#549 `_: the open file descriptor limit for the Ansible process is increased to the available hard limit. It is common for distributions to ship with a much higher hard limit than their default soft limit, allowing *"too many open files"* errors to be avoided more often in large runs without user configuration. * `#578 `_: the extension could crash while rendering an error message, due to an incorrect format string. * `#590 `_: the importer can handle modules that replace themselves in :mod:`sys.modules` during import. * `#591 `_: the target's current working directory is restored to a known-existent directory between tasks to ensure :func:`os.getcwd` will not fail when called, in the same way that :class:`AnsibleModule` restores it during initialization. However this restore happens before the module ever executes, ensuring any code that calls :func:`os.getcwd` prior to :class:`AnsibleModule` initialization, such as the Ansible 2.7 ``pip`` module, cannot fail due to the behavior of a prior task. * `#593 `_: the SSH connection method exposes ``mitogen_ssh_keepalive_interval`` and ``mitogen_ssh_keepalive_count`` variables, and the default timeout for an SSH server has been increased from `15*3` seconds to `30*10` seconds. * `#600 `_: functionality to reflect changes to ``/etc/environment`` in the running interpreter did not account for Unicode file contents. Now the file may contain data in any single byte encoding. * `#602 `_: connection configuration is more accurately inferred for `meta: reset_connection`, the `synchronize` module, and for any other action plug-ins that establish new connections of their own. * `7ae926b3 `_: the ``lineinfile`` module began leaking writable temporary file descriptors since Ansible 2.7.0. When ``lineinfile`` was used to create or modify a script, and that script was later executed, the execution could fail with "*text file busy*" due to the leaked descriptor. Temporary descriptors are now tracked and cleaned up on exit for all modules. Core Library ~~~~~~~~~~~~ * Log readability is improving, and many :func:`repr` strings are more descriptive. The old pseudo-function-call format is slowly migrating to human-readable output where possible. For example, *"Stream(ssh:123).connect()"* might be written *"connecting to ssh:123"*. * :func:`bytearray` was removed from the list of supported serialization types. It was never portable between Python versions, unused, and never made much sense to support. * `#170 `_: to improve subprocess management and asynchronous connect, a :class:`mitogen.parent.TimerList` interface is available, accessible as :attr:`Broker.timers` in an asynchronous context. * `#419 `_: the internal :class:`mitogen.core.Stream` has been refactored into 7 new classes, modularizing protocol behaviour, output buffering, line-oriented input parsing, option handling and connection management. Connection setup is internally asynchronous, laying almost all the groundwork needed for fully asynchronous connect, proxied Ansible become plug-ins, and integrating `libssh `_. * `#169 `_, `#419 `_: zombie child reaping has vastly improved, by using timers to efficiently poll for a slow child to finish exiting. Polling avoids relying on process-global configuration such as a `SIGCHLD` handler, or :func:`signal.set_wakeup_fd` available in modern Python. * `#256 `_, `#419 `_: most :func:`os.dup` use was eliminated, along with almost all manual file descriptor management. Descriptors are trapped in :func:`os.fdopen` objects at creation, ensuring a leaked object will close itself, and ensuring every descriptor is fused to a `closed` flag, preventing historical bugs where a double close could destroy descriptors belonging to unrelated streams. * `#606 `_: fix example code on the documentation front page. * `a5536c35 `_: avoid quadratic buffer management when logging lines received from a child's redirected standard IO. Thanks! ~~~~~~~ Mitogen would not be possible without the support of users. A huge thanks for bug reports, testing, features and fixes in this release contributed by `Andreas Hubert `_. `Anton Markelov `_, `Dan `_, `Dave Cottlehuber `_, `El Mehdi CHAOUKI `_, `James Hogarth `_, `Nigel Metheringham `_, `Orion Poplawski `_, `Pieter Voet `_, `Stefane Fermigier `_, `Szabó Dániel Ernő `_, `Ulrich Schreiner `_, `Yuki Nishida `_, `@DavidVentura `_, `@ghp-rr `_, `@rizzly `_, and `@tho86 `_. v0.2.7 (2019-05-19) ------------------- This release primarily exists to add a descriptive error message when running on Ansible 2.8, which is not yet supported. Fixes ~~~~~ * `#557 `_: fix a crash when running on machines with high CPU counts. * `#570 `_: the ``firewalld`` module internally caches a dbus name that changes across ``firewalld`` restarts, causing a failure if the service is restarted between ``firewalld`` module invocations. * `#575 `_: fix a crash when rendering an error message to indicate no usable temporary directories could be found. * `#576 `_: fix a crash during startup on SuSE Linux 11, due to an incorrect version compatibility check in the Mitogen code. * `#581 `_: a ``mitogen_mask_remote_name`` Ansible variable is exposed, to allow masking the username, hostname and process ID of ``ansible-playbook`` running on the controller machine. * `#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! ~~~~~~~ Mitogen would not be possible without the support of users. A huge thanks for bug reports, testing, features and fixes in this release contributed by `Orion Poplawski `_, `Thibaut Barrère `_, `@Moumoutaru `_, and `@polski-g `_. v0.2.6 (2019-03-06) ------------------- Fixes ~~~~~ * `#542 `_: some versions of OS X ship a default Python that does not support :func:`select.poll`. Restore the 0.2.3 behaviour of defaulting to Kqueue in this case, but still prefer :func:`select.poll` if it is available. * `#545 `_: an optimization introduced in `#493 `_ caused a 64-bit integer to be assigned to a 32-bit field on ARM 32-bit targets, causing runs to fail. * `#548 `_: `mitogen_via=` could fail when the selected transport was set to ``smart``. * `#550 `_: avoid some broken TTY-related `ioctl()` calls on Windows Subsystem for Linux 2016 Anniversary Update. * `#554 `_: third party Ansible action plug-ins that invoked :func:`_make_tmp_path` repeatedly could trigger an assertion failure. * `#555 `_: work around an old idiom that reloaded :mod:`sys` in order to change the interpreter's default encoding. * `ffae0355 `_: needless information was removed from the documentation and installation procedure. Core Library ~~~~~~~~~~~~ * `#535 `_: to support function calls on a service pool from another thread, :class:`mitogen.select.Select` additionally permits waiting on :class:`mitogen.core.Latch`. * `#535 `_: :class:`mitogen.service.Pool.defer` allows any function to be enqueued for the thread pool from another thread. * `#535 `_: a new :mod:`mitogen.os_fork` module provides a :func:`os.fork` wrapper that pauses thread activity during fork. On Python<2.6, :class:`mitogen.core.Broker` and :class:`mitogen.service.Pool` automatically record their existence so that a :func:`os.fork` monkey-patch can automatically pause them for any attempt to start a subprocess. * `ca63c26e `_: :meth:`mitogen.core.Latch.put`'s `obj` argument was made optional. Thanks! ~~~~~~~ Mitogen would not be possible without the support of users. A huge thanks for bug reports, testing, features and fixes in this release contributed by `Fabian Arrotin `_, `Giles Westwood `_, `Matt Layman `_, `Percy Grunwald `_, `Petr Enkov `_, `Tony Finch `_, `@elbunda `_, and `@zyphermonkey `_. v0.2.5 (2019-02-14) ------------------- Fixes ~~~~~ * `#511 `_, `#536 `_: changes in 0.2.4 to repair ``delegate_to`` handling broke default ``ansible_python_interpreter`` handling. Test coverage was added. * `#532 `_: fix a race in the service used to propagate Ansible modules, that could easily manifest when starting asynchronous tasks in a loop. * `#536 `_: changes in 0.2.4 to support Python 2.4 interacted poorly with modules that imported ``simplejson`` from a controller that also loaded an incompatible newer version of ``simplejson``. * `#537 `_: a swapped operator in the CPU affinity logic meant 2 cores were reserved on 1`_: the source distribution includes a ``LICENSE`` file. * `#539 `_: log output is no longer duplicated when the Ansible ``log_path`` setting is enabled. * `#540 `_: the ``stderr`` stream of async module invocations was previously discarded. * `#541 `_: Python error logs originating from the ``boto`` package are quiesced, and only appear in ``-vvv`` output. This is since EC2 modules may trigger errors during normal operation, when retrying transiently failing requests. * `748f5f67 `_, `21ad299d `_, `8ae6ca1d `_, `7fd0d349 `_: the ``ansible_ssh_host``, ``ansible_ssh_user``, ``ansible_user``, ``ansible_become_method``, and ``ansible_ssh_port`` variables more correctly match typical behaviour when ``mitogen_via=`` is active. * `2a8567b4 `_: fix a race initializing a child's service thread pool on Python 3.4+, due to a change in locking scheme used by the Python import mechanism. Thanks! ~~~~~~~ Mitogen would not be possible without the support of users. A huge thanks for bug reports, testing, features and fixes in this release contributed by `Carl George `_, `Guy Knights `_, and `Josh Smift `_. v0.2.4 (2019-02-10) ------------------- Mitogen for Ansible ~~~~~~~~~~~~~~~~~~~ This release includes a huge variety of important fixes and new optimizations. It is 35% faster than 0.2.3 on a synthetic 64 target run that places heavy load on the connection multiplexer. Enhancements ^^^^^^^^^^^^ * `#76 `_, `#351 `_, `#352 `_: disconnect propagation has improved, allowing Ansible to cancel waits for responses from abruptly disconnected targets. This ensures a task will reliably fail rather than hang, for example on network failure or EC2 instance maintenance. * `#369 `_, `#407 `_: :meth:`Connection.reset` is implemented, allowing `meta: reset_connection `_ to shut down the remote interpreter as documented, and improving support for the `reboot `_ module. * `09aa27a6 `_: the ``mitogen_host_pinned`` strategy wraps the ``host_pinned`` strategy introduced in Ansible 2.7. * `#477 `_: Python 2.4 is fully supported by the core library and tested automatically, in any parent/child combination of 2.4, 2.6, 2.7 and 3.6 interpreters. * `#477 `_: Ansible 2.3 is fully supported and tested automatically. In combination with the core library Python 2.4 support, this allows Red Hat Enterprise Linux 5 targets to be managed with Mitogen. The ``simplejson`` package need not be installed on such targets, as is usually required by Ansible. * `#412 `_: to simplify diagnosing connection configuration problems, Mitogen ships a ``mitogen_get_stack`` action that is automatically added to the action plug-in path. See :ref:`mitogen-get-stack` for more information. * `152effc2 `_, `bd4b04ae `_: a CPU affinity policy was added for Linux controllers, reducing latency and SMP overhead on hot paths exercised for every task. This yielded a 19% speedup in a 64-target job composed of many short tasks, and should easily be visible as a runtime improvement in many-host runs. * `2b44d598 `_: work around a defective caching mechanism by pre-heating it before spawning workers. This saves 40% runtime on a synthetic repetitive task. * `0979422a `_: an expensive dependency scanning step was redundantly invoked for every task, bottlenecking the connection multiplexer. * `eaa990a97 `_: a new ``mitogen_ssh_compression`` variable is supported, allowing Mitogen's default SSH compression to be disabled. SSH compression is a large contributor to CPU usage in many-target runs, and severely limits file transfer. On a `"shell: hostname"` task repeated 500 times, Mitogen requires around 800 bytes per task with compression, rising to 3 KiB without. File transfer throughput rises from ~25MiB/s when enabled to ~200MiB/s when disabled. * `#260 `_, `a18a083c `_: brokers no longer wait for readiness indication to transmit, and instead assume transmission will succeed. As this is usually true, one loop iteration and two poller reconfigurations are avoided, yielding a significant reduction in interprocess round-trip latency. * `#415 `_, `#491 `_, `#493 `_: the interface employed for in-process queues changed from `kqueue `_ / `epoll `_ to `poll() `_, which requires no setup or teardown, yielding a 38% latency reduction for inter-thread communication. Fixes ^^^^^ * `#251 `_, `#359 `_, `#396 `_, `#401 `_, `#404 `_, `#412 `_, `#434 `_, `#436 `_, `#465 `_: connection delegation and ``delegate_to:`` handling suffered a major regression in 0.2.3. The 0.2.2 behaviour has been restored, and further work has been made to improve the compatibility of connection delegation's configuration building methods. * `#323 `_, `#333 `_: work around a Windows Subsystem for Linux bug that caused tracebacks to appear during shutdown. * `#334 `_: the SSH method tilde-expands private key paths using Ansible's logic. Previously the path was passed unmodified to SSH, which expanded it using :func:`pwd.getpwnam`. This differs from :func:`os.path.expanduser`, which uses the ``HOME`` environment variable if it is set, causing behaviour to diverge when Ansible was invoked across user accounts via ``sudo``. * `#364 `_: file transfers from controllers running Python 2.7.2 or earlier could be interrupted due to a forking bug in the :mod:`tempfile` module. * `#370 `_: the Ansible `reboot `_ module is supported. * `#373 `_: the LXC and LXD methods print a useful hint on failure, as no useful error is normally logged to the console by these tools. * `#374 `_, `#391 `_: file transfer and module execution from 2.x controllers to 3.x targets was broken due to a regression caused by refactoring, and compounded by `#426 `_. * `#400 `_: work around a threading bug in the AWX display callback when running with high verbosity setting. * `#409 `_: the setns method was silently broken due to missing tests. Basic coverage was added to prevent a recurrence. * `#409 `_: the LXC and LXD methods support ``mitogen_lxc_path`` and ``mitogen_lxc_attach_path`` variables to control the location of third pary utilities. * `#410 `_: the sudo method supports the SELinux ``--type`` and ``--role`` options. * `#420 `_: if a :class:`Connection` was constructed in the Ansible top-level process, for example while executing ``meta: reset_connection``, resources could become undesirably shared in subsequent children. * `#426 `_: an oversight while porting to Python 3 meant no automated 2->3 tests were running. A significant number of 2->3 bugs were fixed, mostly in the form of Unicode/bytes mismatches. * `#429 `_: the ``sudo`` method can now recognize internationalized password prompts. * `#362 `_, `#435 `_: the previous fix for slow Python 2.x subprocess creation on Red Hat caused newly spawned children to have a reduced open files limit. A more intrusive fix has been added to directly address the problem without modifying the subprocess environment. * `#397 `_, `#454 `_: the previous approach to handling modern Ansible temporary file cleanup was too aggressive, and could trigger early finalization of Cython-based extension modules, leading to segmentation faults. * `#499 `_: the ``allow_same_user`` Ansible configuration setting is respected. * `#527 `_: crashes in modules are trapped and reported in a manner that matches Ansible. In particular, a module crash no longer leads to an exception that may crash the corresponding action plug-in. * `dc1d4251 `_: the ``synchronize`` module could fail with the Docker transport due to a missing attribute. * `599da068 `_: fix a race when starting async tasks, where it was possible for the controller to observe no status file on disk before the task had a chance to write one. * `2c7af9f04 `_: Ansible modules were repeatedly re-transferred. The bug was hidden by the previously mandatorily enabled SSH compression. Core Library ~~~~~~~~~~~~ * `#76 `_: routing records the destination context IDs ever received on each stream, and when disconnection occurs, propagates :data:`mitogen.core.DEL_ROUTE` messages towards every stream that ever communicated with the disappearing peer, rather than simply towards parents. Conversations between nodes anywhere in the tree receive :data:`mitogen.core.DEL_ROUTE` when either participant disconnects, allowing receivers to wake with :class:`mitogen.core.ChannelError`, even when one participant is not a parent of the other. * `#109 `_, `57504ba6 `_: newer Python 3 releases explicitly populate :data:`sys.meta_path` with importer internals, causing Mitogen to install itself at the end of the importer chain rather than the front. * `#310 `_: support has returned for trying to figure out the real source of non-module objects installed in :data:`sys.modules`, so they can be imported. This is needed to handle syntax sugar used by packages like :mod:`plumbum`. * `#349 `_: an incorrect format string could cause large stack traces when attempting to import built-in modules on Python 3. * `#387 `_, `#413 `_: dead messages include an optional reason in their body. This is used to cause :class:`mitogen.core.ChannelError` to report far more useful diagnostics at the point the error occurs that previously would have been buried in debug log output from an unrelated context. * `#408 `_: a variety of fixes were made to restore Python 2.4 compatibility. * `#399 `_, `#437 `_: ignore a :class:`DeprecationWarning` to avoid failure of the ``su`` method on Python 3.7. * `#405 `_: if an oversized message is rejected, and it has a ``reply_to`` set, a dead message is returned to the sender. This ensures function calls exceeding the configured maximum size crash rather than hang. * `#406 `_: :class:`mitogen.core.Broker` did not call :meth:`mitogen.core.Poller.close` during shutdown, leaking the underlying poller FD in masters and parents. * `#406 `_: connections could leak FDs when a child process failed to start. * `#288 `_, `#406 `_, `#417 `_: connections could leave FD wrapper objects that had not been closed lying around to be closed during garbage collection, causing reused FD numbers to be closed at random moments. * `#411 `_: the SSH method typed "``y``" rather than the requisite "``yes``" when `check_host_keys="accept"` was configured. This would lead to connection timeouts due to the hung response. * `#414 `_, `#425 `_: avoid deadlock of forked children by reinitializing the :mod:`mitogen.service` pool lock. * `#416 `_: around 1.4KiB of memory was leaked on every RPC, due to a list of strong references keeping alive any handler ever registered for disconnect notification. * `#418 `_: the :func:`mitogen.parent.iter_read` helper would leak poller FDs, because execution of its :keyword:`finally` block was delayed on Python 3. Now callers explicitly close the generator when finished. * `#422 `_: the fork method could fail to start if :data:`sys.stdout` was opened in block buffered mode, and buffered data was pending in the parent prior to fork. * `#438 `_: a descriptive error is logged when stream corruption is detected. * `#439 `_: descriptive errors are raised when attempting to invoke unsupported function types. * `#444 `_: messages regarding unforwardable extension module are no longer logged as errors. * `#445 `_: service pools unregister the :data:`mitogen.core.CALL_SERVICE` handle at shutdown, ensuring any outstanding messages are either processed by the pool as it shuts down, or have dead messages sent in reply to them, preventing peer contexts from hanging due to a forgotten buffered message. * `#446 `_: given thread A calling :meth:`mitogen.core.Receiver.close`, and thread B, C, and D sleeping in :meth:`mitogen.core.Receiver.get`, previously only one sleeping thread would be woken with :class:`mitogen.core.ChannelError` when the receiver was closed. Now all threads are woken per the docstring. * `#447 `_: duplicate attempts to invoke :meth:`mitogen.core.Router.add_handler` cause an error to be raised, ensuring accidental re-registration of service pools are reported correctly. * `#448 `_: the import hook implementation now raises :class:`ModuleNotFoundError` instead of :class:`ImportError` in Python 3.6 and above, to cope with an upcoming version of the :mod:`subprocess` module requiring this new subclass to be raised. * `#453 `_: the loggers used in children for standard IO redirection have propagation disabled, preventing accidental reconfiguration of the :mod:`logging` package in a child from setting up a feedback loop. * `#456 `_: a descriptive error is logged when :meth:`mitogen.core.Broker.defer` is called after the broker has shut down, preventing new messages being enqueued that will never be sent, and subsequently producing a program hang. * `#459 `_: the beginnings of a :meth:`mitogen.master.Router.get_stats` call has been added. The initial statistics cover the module loader only. * `#462 `_: Mitogen could fail to open a PTY on broken Linux systems due to a bad interaction between the glibc :func:`grantpt` function and an incorrectly mounted ``/dev/pts`` filesystem. Since correct group ownership is not required in most scenarios, when this problem is detected, the PTY is allocated and opened directly by the library. * `#479 `_: Mitogen could fail to 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 `_: 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 `_: the test suite didn't generate a code coverage report if any test failed. * `#524 `_: Python 3.6+ emitted a :class:`DeprecationWarning` for :func:`mitogen.utils.run_with_router`. * `#529 `_: Code coverage of the test suite was not measured across all Python versions. * `16ca111e `_: handle OpenSSH 7.5 permission denied prompts when ``~/.ssh/config`` rewrites are present. * `9ec360c2 `_: a new :meth:`mitogen.core.Broker.defer_sync` utility function is provided. * `f20e0bba `_: :meth:`mitogen.service.FileService.register_prefix` permits granting unprivileged access to whole filesystem subtrees, rather than single files at a time. * `8f85ee03 `_: :meth:`mitogen.core.Router.myself` returns a :class:`mitogen.core.Context` referring to the current process. * `824c7931 `_: exceptions raised by the import hook were updated to include probable reasons for a failure. * `57b652ed `_: a stray import meant an extra roundtrip and ~4KiB of data was wasted for any context that imported :mod:`mitogen.parent`. Thanks! ~~~~~~~ Mitogen would not be possible without the support of users. A huge thanks for bug reports, testing, features and fixes in this release contributed by `Alex Willmer `_, `Andreas Krüger `_, `Anton Stroganov `_, `Berend De Schouwer `_, `Brian Candler `_, `dsgnr `_, `Duane Zamrok `_, `Eric Chang `_, `Gerben Meijer `_, `Guy Knights `_, `Jesse London `_, `Jiří Vávra `_, `Johan Beisser `_, `Jonathan Rosser `_, `Josh Smift `_, `Kevin Carter `_, `Mehdi `_, `Michael DeHaan `_, `Michal Medvecky `_, `Mohammed Naser `_, `Peter V. Saveliev `_, `Pieter Avonts `_, `Ross Williams `_, `Sergey `_, `Stéphane `_, `Strahinja Kustudic `_, `Tom Parker-Shemilt `_, `Younès HAFRI `_, `@killua-eu `_, `@myssa91 `_, `@ohmer1 `_, `@s3c70r `_, `@syntonym `_, `@trim777 `_, `@whky `_, and `@yodatak `_. v0.2.3 (2018-10-23) ------------------- Mitogen for Ansible ~~~~~~~~~~~~~~~~~~~ Enhancements ^^^^^^^^^^^^ * `#315 `_, `#392 `_: Ansible 2.6 and 2.7 are supported. * `#321 `_, `#336 `_: temporary file handling was simplified, undoing earlier damage caused by compatibility fixes, improving 2.6 compatibility, and avoiding two network roundtrips for every related action (`assemble `_, `aws_s3 `_, `copy `_, `patch `_, `script `_, `template `_, `unarchive `_, `uri `_). See :ref:`ansible_tempfiles` for a complete description. * `#376 `_, `#377 `_: the ``kubectl`` connection type is now supported. Contributed by Yannig Perré. * `084c0ac0 `_: avoid a roundtrip in `copy `_ and `template `_ due to an unfortunate default. * `7458dfae `_: avoid a roundtrip when transferring files smaller than 124KiB. Copy and template actions are now 2-RTT, reducing runtime for a 20-iteration template loop over a 250 ms link from 30 seconds to 10 seconds compared to v0.2.2, down from 120 seconds compared to vanilla. * `#337 `_: To avoid a scaling limitation, a PTY is no longer allocated for an SSH connection unless the configuration specifies a password. * `d62e6e2a `_: many-target runs executed the dependency scanner redundantly due to missing synchronization, wasting significant runtime in the connection multiplexer. In one case work was reduced by 95%, which may manifest as faster runs. * `5189408e `_: threads are cooperatively scheduled, minimizing `GIL `_ contention, and reducing context switching by around 90%. This manifests as an overall improvement, but is easily noticeable on short many-target runs, where startup overhead dominates runtime. * The `faulthandler `_ module is automatically activated if it is installed, simplifying debugging of hangs. See :ref:`diagnosing-hangs` for details. * The ``MITOGEN_DUMP_THREAD_STACKS`` environment variable's value now indicates the number of seconds between stack dumps. See :ref:`diagnosing-hangs` for details. Fixes ^^^^^ * `#251 `_, `#340 `_: Connection Delegation could establish connections to the wrong target when ``delegate_to:`` is present. * `#291 `_: when Mitogen had previously been installed using ``pip`` or ``setuptools``, the globally installed version could conflict with a newer version bundled with an extension that had been installed using the documented steps. Now the bundled library always overrides over any system-installed copy. * `#324 `_: plays with a `custom module_utils `_ would fail due to fallout from the Python 3 port and related tests being disabled. * `#331 `_: the connection multiplexer subprocess always exits before the main Ansible process, ensuring logs generated by it do not overwrite the user's prompt when ``-vvv`` is enabled. * `#332 `_: support a new :func:`sys.excepthook`-based module exit mechanism added in Ansible 2.6. * `#338 `_: compatibility: changes to ``/etc/environment`` and ``~/.pam_environment`` made by a task are reflected in the runtime environment of subsequent tasks. See :ref:`ansible_process_env` for a complete description. * `#343 `_: the sudo ``--login`` option is supported. * `#344 `_: connections no longer fail when the controller's login username contains slashes. * `#345 `_: the ``IdentitiesOnly yes`` option is no longer supplied to OpenSSH by default, better matching Ansible's behaviour. * `#355 `_: tasks configured to run in an isolated forked subprocess were forked from the wrong parent context. This meant built-in modules overridden via a custom ``module_utils`` search path may not have had any effect. * `#362 `_: to work around a slow algorithm in the :mod:`subprocess` module, the maximum number of open files in processes running on the target is capped to 512, reducing the work required to start a subprocess by >2000x in default CentOS configurations. * `#397 `_: recent Mitogen master versions could fail to clean up temporary directories in a number of circumstances, and newer Ansibles moved to using :mod:`atexit` to effect temporary directory cleanup in some circumstances. * `b9112a9c `_, `2c287801 `_: OpenSSH 7.5 permission denied prompts are now recognized. Contributed by Alex Willmer. * A missing check caused an exception traceback to appear when using the ``ansible`` command-line tool with a missing or misspelled module name. * Ansible since >=2.7 began importing :mod:`__main__` from :mod:`ansible.module_utils.basic`, causing an error during execution, due to the controller being configured to refuse network imports outside the ``ansible.*`` namespace. Update the target implementation to construct a stub :mod:`__main__` module to satisfy the otherwise seemingly vestigial import. Core Library ~~~~~~~~~~~~ * A new :class:`mitogen.parent.CallChain` class abstracts safe pipelining of related function calls to a target context, cancelling the chain if an exception occurs. * `#305 `_: fix a long-standing minor race relating to the logging framework, where *no route for Message..* would frequently appear during startup. * `#313 `_: :meth:`mitogen.parent.Context.call` was documented as capable of accepting static methods. While possible on Python 2.x the result is ugly, and in every case it should be trivial to replace with a classmethod. The documentation was fixed. * `#337 `_: to avoid a scaling limitation, a PTY is no longer allocated for each OpenSSH client if it can be avoided. PTYs are only allocated if a password is supplied, or when `host_key_checking=accept`. This is since Linux has a default of 4096 PTYs (``kernel.pty.max``), while OS X has a default of 127 and an absolute maximum of 999 (``kern.tty.ptmx_max``). * `#339 `_: the LXD connection method was erroneously executing LXC Classic commands. * `#345 `_: the SSH connection method allows optionally disabling ``IdentitiesOnly yes``. * `#356 `_: if the master Python process does not have :data:`sys.executable` set, the default Python interpreter used for new children on the local machine defaults to ``"/usr/bin/python"``. * `#366 `_, `#380 `_: attempts by children to import :mod:`__main__` where the main program module lacks an execution guard are refused, and an error is logged. This prevents a common and highly confusing error when prototyping new scripts. * `#371 `_: the LXC connection method uses a more compatible method to establish an non-interactive session. Contributed by Brian Candler. * `af2ded66 `_: add :func:`mitogen.fork.on_fork` to allow non-Mitogen managed process forks to clean up Mitogen resources in the child. * `d6784242 `_: the setns method always resets ``HOME``, ``SHELL``, ``LOGNAME`` and ``USER`` environment variables to an account in the target container, defaulting to ``root``. * `830966bf `_: the UNIX listener no longer crashes if the peer process disappears in the middle of connection setup. Thanks! ~~~~~~~ Mitogen would not be possible without the support of users. A huge thanks for bug reports, testing, features and fixes in this release contributed by `Alex Russu `_, `Alex Willmer `_, `atoom `_, `Berend De Schouwer `_, `Brian Candler `_, `Dan Quackenbush `_, `dsgnr `_, `Jesse London `_, `John McGrath `_, `Jonathan Rosser `_, `Josh Smift `_, `Luca Nunzi `_, `Orion Poplawski `_, `Peter V. Saveliev `_, `Pierre-Henry Muller `_, `Pierre-Louis Bonicoli `_, `Prateek Jain `_, `RedheatWei `_, `Rick Box `_, `nikitakazantsev12 `_, `Tawana Musewe `_, `Timo Beckers `_, and `Yannig Perré `_. v0.2.2 (2018-07-26) ------------------- Mitogen for Ansible ~~~~~~~~~~~~~~~~~~~ * `#291 `_: ``ansible_*_interpreter`` variables are parsed using a restrictive shell-like syntax, supporting a common idiom where ``ansible_python_interpreter`` is set to ``/usr/bin/env python``. * `#299 `_: fix the ``network_cli`` connection type when the Mitogen strategy is active. Mitogen cannot help network device connections, however it should still be possible to use device connections while Mitogen is active. * `#301 `_: variables like ``$HOME`` in the ``remote_tmp`` setting are evaluated correctly. * `#303 `_: the :ref:`doas` become method is supported. Contributed by `Mike Walker `_. * `#309 `_: fix a regression to process environment cleanup, caused by the change in v0.2.1 to run local tasks with the correct environment. * `#317 `_: respect the verbosity setting when writing to Ansible's ``log_path``, if it is enabled. Child log filtering was also incorrect, causing the master to needlessly wake many times. This nets a 3.5% runtime improvement running against the local machine. * The ``mitogen_ssh_debug_level`` variable is supported, permitting SSH debug output to be included in Mitogen's ``-vvv`` output when both are specified. Core Library ~~~~~~~~~~~~ * `#291 `_: the ``python_path`` parameter may specify an argument vector prefix rather than a string program path. * `#300 `_: the broker could crash on OS X during shutdown due to scheduled `kqueue `_ filter changes for descriptors that were closed before the IO loop resumes. As a temporary workaround, kqueue's bulk change feature is not used. * `#303 `_: the :ref:`doas` become method is now supported. Contributed by `Mike Walker `_. * `#307 `_: SSH login banner output containing the word 'password' is no longer confused for a password prompt. * `#319 `_: SSH connections would fail immediately on Windows Subsystem for Linux, due to use of `TCSAFLUSH` with :func:`termios.tcsetattr`. The flag is omitted if WSL is detected. * `#320 `_: The OS X poller could spuriously wake up due to ignoring an error bit set on events returned by the kernel, manifesting as a failure to read from an unrelated descriptor. * `#342 `_: The ``network_cli`` connection type would fail due to a missing internal SSH plugin method. * Standard IO forwarding accidentally configured the replacement ``stdout`` and ``stderr`` write descriptors as non-blocking, causing subprocesses that generate more output than kernel buffer space existed to throw errors. The write ends are now configured as blocking. * When :func:`mitogen.core.enable_profiling` is active, :mod:`mitogen.service` threads are profiled just like other threads. * The ``ssh_debug_level`` parameter is supported, permitting SSH debug output to be redirected to a Mitogen logger when specified. * Debug logs containing command lines are printed with the minimal quoting and escaping required. Thanks! ~~~~~~~ Mitogen would not be possible without the support of users. A huge thanks for the bug reports and pull requests in this release contributed by `Alex Russu `_, `Andy Freeland `_, `Ayaz Ahmed Khan `_, `Colin McCarthy `_, `Dan Quackenbush `_, `Duane Zamrok `_, `Gonzalo Servat `_, `Guy Knights `_, `Josh Smift `_, `Mark Janssen `_, `Mike Walker `_, `Orion Poplawski `_, `falbanese `_, `Tawana Musewe `_, and `Zach Swanson `_. v0.2.1 (2018-07-10) ------------------- Mitogen for Ansible ~~~~~~~~~~~~~~~~~~~ * `#297 `_: compatibility: local actions set their working directory to that of their defining playbook, and inherit a process environment as if they were executed as a subprocess of the forked task worker. v0.2.0 (2018-07-09) ------------------- Mitogen 0.2.x is the inaugural feature-frozen branch eligible for fixes only, except for problem areas listed as in-scope below. While stable from a development perspective, it should still be considered "beta" at least for the initial releases. **In Scope** * Python 3.x performance improvements * Subprocess reaping improvements * Major documentation improvements * PyPI/packaging improvements * Test suite improvements * Replacement CI system to handle every supported OS * Minor deviations from vanilla Ansible behaviour * Ansible ``raw`` action support The goal is a *tick/tock* model where even-numbered series are a maturation of the previous unstable series, and unstable series are released on PyPI with ``--pre`` enabled. The API and user visible behaviour should remain unchanged within a stable series. Mitogen for Ansible ~~~~~~~~~~~~~~~~~~~ * Support for Ansible 2.3 - 2.7.x and any mixture of Python 2.6, 2.7 or 3.6 on controller and target nodes. * Drop-in support for many Ansible connection types. * Preview of Connection Delegation feature. * Built-in file transfer compatible with connection delegation. Core Library ~~~~~~~~~~~~ * Synchronous connection establishment via OpenSSH, sudo, su, Docker, LXC and FreeBSD Jails, local subprocesses and :func:`os.fork`. Parallel connection setup is possible using multiple threads. Connections may be used from one or many threads after establishment. * UNIX masters and children, with Linux, MacOS, FreeBSD, NetBSD, OpenBSD and Windows Subsystem for Linux explicitly supported. * Automatic tests covering Python 2.6, 2.7 and 3.6 on Linux only.