incompatible with regpg Ansible plugin

[fanf2]

I am using ansible 2.7.5 from Debian stretch-backports. Host and target are Debian stretch.

I am using the regpg gpg_d action plugin, which you can get from https://dotat.at/prog/regpg/. It's basically a clone-and-hack of Ansible's copy or template modules. Details of a minimal reproduction setup below. It works without Mitogen, but I might be mis-using the API in a way that is revealed by Mitogen...

I have tried Mitogen 0.2.5 (from the git tag) and latest Mitogen master. The error output is below; it occurs (in my code) around https://dotat.at/cgi/git/regpg.git/blob/HEAD:/ansible/action.py#l100

[pid 3135] 13:27:29.905395 D ansible_mitogen.mixins: _make_tmp_path(remote_user=None)
[pid 3135] 13:27:29.906262 D mitogen: unix.connect(path='/tmp/mitogen_unix_VpUUlK.sock')
[pid 3135] 13:27:29.907130 D mitogen: unix.connect(): local ID is 1003, remote is 0
[pid 3031] 13:27:29.907124 D mitogen: mitogen.unix.Listener('/tmp/mitogen_unix_VpUUlK.sock'): accepted mitogen.core.Stream('unix_client.3135')
[pid 3135] 13:27:29.908740 D ansible_mitogen.connection: Temporary directory: u'/home/fanf2/.ansible/tmp/ansible_mitogen_action_0cfadb91dc0a2803'
[pid 3135] 13:27:29.908866 D mitogen: CallChain(Context(2, u'local.3072')).call_no_reply(): posix.mkdir(u'/home/fanf2/.ansible/tmp/ansible_mitogen_action_0cfadb91dc0a2803')
[pid 3135] 13:27:29.909447 D ansible_mitogen.mixins: _remote_expand_user(u'/tmp/foo', sudoable=True)
[pid 3031] 13:27:29.913255 D mitogen.ctx.local.3072: mitogen: _dispatch_one(('grey.csi.cam.ac.uk-3135-7f21bd444700-582e022b1afe0', u'posix', None, u'mkdir', (u'/home/fanf2/.ansible/tmp/ansible_mitogen_action_0cfadb91dc0a2803',), Kwargs({})))
[pid 3031] 13:27:29.913637 D mitogen.ctx.local.3072: mitogen: _dispatch_calls: Message(2, 1003, 0, 101, 0, '\x80\x02(U2grey.csi.cam.ac.uk-3135-7f21bd444700-582e022b'..184) -> None
[pid 3135] 13:27:30.046436 D ansible_mitogen.mixins: _make_tmp_path(remote_user=u'fanf2')
[pid 3135] 13:27:30.047673 D mitogen: CallChain(Context(2, u'local.3072')).call_no_reply(): ansible_mitogen.target.prune_tree(u'/home/fanf2/.ansible/tmp/ansible_mitogen_action_0cfadb91dc0a2803')
[pid 3135] 13:27:30.048189 D mitogen: CallChain(Context(2, u'local.3072')).call_no_reply(): mitogen.core.Dispatcher.forget_chain('grey.csi.cam.ac.uk-3135-7f21bd444700-582e022b1afe0')
[pid 3031] 13:27:30.049134 D ansible_mitogen.services: ContextService().put(Context(2, u'local.3072'))
[pid 3031] 13:27:30.049511 D mitogen.ctx.local.3072: mitogen: _dispatch_one((None, u'ansible_mitogen.target', None, u'prune_tree', (u'/home/fanf2/.ansible/tmp/ansible_mitogen_action_0cfadb91dc0a2803',), Kwargs({})))
[pid 3031] 13:27:30.049903 D mitogen.ctx.local.3072: mitogen: _dispatch_calls: Message(2, 1003, 0, 101, 0, '\x80\x02(NX\x16\x00\x00\x00ansible_mitogen.targetNX\n\x00\x00\x00prune_treeX@\x00'..153) -> None
[pid 3031] 13:27:30.050023 D mitogen.ctx.local.3072: mitogen: _dispatch_one((None, u'mitogen.core', u'Dispatcher', u'forget_chain', ('grey.csi.cam.ac.uk-3135-7f21bd444700-582e022b1afe0',), Kwargs({})))
[pid 3031] 13:27:30.050123 D mitogen.ctx.local.3072: mitogen: _dispatch_calls: Message(2, 1003, 0, 101, 0, '\x80\x02(NX\x0c\x00\x00\x00mitogen.coreX\n\x00\x00\x00Dispatcherq\x01X\x0c\x00\x00\x00forget_'..144) -> None
[pid 3135] 13:27:30.049887 D mitogen: mitogen.core.Stream('unix_listener.3031').on_disconnect()
[pid 3031] 13:27:30.050276 D mitogen: mitogen.core.Stream('unix_client.3135').on_disconnect()
[pid 3135] 13:27:30.050302 D mitogen: Waker(Broker(0x7f21b5ca3cd0) rfd=10, wfd=12).on_disconnect()
[pid 3135] 13:27:30.050618 D mitogen: Router(Broker(0x7f21b5ca3cd0)): stats: 0 module requests in 0 ms, 0 sent (0 ms minify time), 0 negative responses. Sent 0.0 kb total, 0.0 kb avg.
The full traceback is:
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/ansible/executor/task_executor.py", line 140, in run
    res = self._execute()
  File "/usr/lib/python2.7/dist-packages/ansible/executor/task_executor.py", line 612, in _execute
    result = self._handler.run(task_vars=variables)
  File "/home/fanf2/gnu/src/mitogen/ansible_mitogen/mixins.py", line 115, in run
    return super(ActionModuleMixin, self).run(tmp, task_vars)
  File "/home/fanf2/work/git/t/testing/plugins/action/gpg_d.py", line 107, in run
    tmp = self._make_tmp_path(remote_user)
  File "/home/fanf2/gnu/src/mitogen/ansible_mitogen/mixins.py", line 182, in _make_tmp_path
    return self._connection._make_tmp_path()
  File "/home/fanf2/gnu/src/mitogen/ansible_mitogen/connection.py", line 715, in _make_tmp_path
    assert getattr(self._shell, 'tmpdir', None) is None
AssertionError

I ran regpg init ansible; echo foo | regpg encrypt foo.asc to install the Ansible plugins, set up the regpg keyring, and make a file to be decrypted. I added the Mitogen lines to ansible.cfg. No other setup except for the playbook, which is:

---
- hosts: localhost
  tasks:
    - gpg_d:
         src: foo.asc
         dest: /tmp/foo

ansible-config dump --only-changed:

DEFAULT_ACTION_PLUGIN_PATH(/home/fanf2/work/git/t/testing/ansible.cfg) = [u'/home/fanf2/work/git/t/testing/plugins/action', u'/home/fanf2/work/git/t/testing/plugins/action']
DEFAULT_FILTER_PLUGIN_PATH(/home/fanf2/work/git/t/testing/ansible.cfg) = [u'/home/fanf2/work/git/t/testing/plugins/filter', u'/home/fanf2/work/git/t/testing/plugins/filter']
DEFAULT_STRATEGY(/home/fanf2/work/git/t/testing/ansible.cfg) = mitogen_linear
DEFAULT_STRATEGY_PLUGIN_PATH(/home/fanf2/work/git/t/testing/ansible.cfg) = [u'/home/fanf2/gnu/src/mitogen/ansible_mitogen/plugins/strategy']

[dw]

It's due to the double call to _make_tmp_path, the extension assumes there can only be one temp directory.

I think the correct behaviour will be to return the existing directory in the second call: Ansible internally only tracks one directory, so having multiple would cause others not to be deleted.

This is a real easy fix, I just need to double check the logic above :)

Thanks for reporting this!

[fanf2]

Thanks!

My understanding of Ansible's internals is rather murky, but the impression I got from all the tmp juggling is that my plugin would be passed a tmp arg if there already was one. (But all of that logic seems rather ridiculous for not being part of the shared plugin code...)

[dw]

The default _make_tmp_path keeps a note of the last generated directory name in the 'shell' plugin, and some magical handling is attached to that particular name. This stuff continues to change rapidly across versions (2.7 featured more work to it IIRC). Regardless, your plugin worked previously and it needs to work again, as there will be more unreported cases just like this.

Looks like returning the same path twice is definitely incorrect, if it wants to keep pipelining temp directory removal it needs to try harder, or disable the pipelining behaviour for subsequent make_tmp_path calls

[fanf2]

Ah, I see that the copy and template actions have changed a fair bit in this area since I last looked. I've tried gpg_d with Mitogen with Ansible 2.3 and 2.4 and it works OK. 2.5 is the first version that explodes.

[dw]

A first pass at this naturally this broke something :) This may take over the weekend, I won't be around so much for the coming 2 days

[fanf2]

OK, thanks for looking in to it :-) I have some acceptable workarounds for the time being.