Add podman connection support

Shameless copy of buildah connection with modifications of invocation to
fit podman CLI.

Signed-off-by: Denis Zalevskiy <dez@aiven.io>

docs/api.rst

@@ -367,6 +367,20 @@ Connection Methods
         Filename or complete path to the ``lxc`` binary. ``PATH`` will be
         searched if given as a filename. Defaults to ``lxc``.
 
+.. currentmodule:: mitogen.parent
+.. method:: Router.podman (container=None, podman_path=None, username=None, \**kwargs)
+
+    Construct a context on the local machine over a ``podman`` invocation.
+    Accepts all parameters accepted by :meth:`local`, in addition to:
+
+    :param str container:
+        The name of the Podman container to connect to.
+    :param str podman_path:
+        Filename or complete path to the ``podman`` binary. ``PATH`` will be
+        searched if given as a filename. Defaults to ``podman``.
+    :param str username:
+        Username to use, defaults to unset.
+
 .. method:: Router.setns (container, kind, username=None, docker_path=None, lxc_info_path=None, machinectl_path=None, \**kwargs)
 
     Construct a context in the style of :meth:`local`, but change the

docs/changelog.rst

@@ -23,6 +23,7 @@ v0.3.1.dev0 (unreleased)
 
 * :gh:issue:`869` Continuous Integration tests are now run with Tox
 * :gh:issue:`869` Continuous Integration tests now cover CentOS 6 & 8, Debian 9 & 11, Ubuntu 16.04 & 20.04
+* :gh:issue:`860` Add initial support for podman connection (w/o Ansible support yet)
 
 
 v0.3.0 (2021-11-24)

mitogen/core.py

@@ -1254,6 +1254,7 @@ class Importer(object):
         'minify',
         'os_fork',
         'parent',
+        'podman',
         'select',
         'service',
         'setns',

mitogen/parent.py

@@ -2505,6 +2505,9 @@ class Router(mitogen.core.Router):
     def ssh(self, **kwargs):
         return self.connect(u'ssh', **kwargs)
 
+    def podman(self, **kwargs):
+        return self.connect(u'podman', **kwargs)
+
 
 class Reaper(object):
     """

mitogen/podman.py

@@ -0,0 +1,74 @@
+# Copyright 2019, David Wilson
+# Copyright 2021, Mitogen contributors
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# 1. Redistributions of source code must retain the above copyright notice,
+# this list of conditions and the following disclaimer.
+#
+# 2. Redistributions in binary form must reproduce the above copyright notice,
+# this list of conditions and the following disclaimer in the documentation
+# and/or other materials provided with the distribution.
+#
+# 3. Neither the name of the copyright holder nor the names of its contributors
+# may be used to endorse or promote products derived from this software without
+# specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+
+# !mitogen: minify_safe
+
+import logging
+
+import mitogen.core
+import mitogen.parent
+
+
+LOG = logging.getLogger(__name__)
+
+
+class Options(mitogen.parent.Options):
+    container = None
+    username = None
+    podman_path = 'podman'
+
+    def __init__(self, container=None, podman_path=None, username=None,
+                 **kwargs):
+        super(Options, self).__init__(**kwargs)
+        assert container is not None
+        self.container = container
+        if podman_path:
+            self.podman_path = podman_path
+        if username:
+            self.username = username
+
+
+class Connection(mitogen.parent.Connection):
+    options_class = Options
+    child_is_immediate_subprocess = False
+
+    # TODO: better way of capturing errors such as "No such container."
+    create_child_args = {
+        'merge_stdio': True
+    }
+
+    def _get_name(self):
+        return u'podman.' + self.options.container
+
+    def get_boot_command(self):
+        args = [self.options.podman_path, 'exec']
+        if self.options.username:
+            args += ['--user=' + self.options.username]
+        args += ["--interactive", "--", self.options.container]
+        return args + super(Connection, self).get_boot_command()

tests/data/stubs/stub-podman.py

@@ -0,0 +1,8 @@
+#!/usr/bin/env python
+
+import sys
+import os
+
+os.environ['ORIGINAL_ARGV'] = repr(sys.argv)
+os.environ['THIS_IS_STUB_PODMAN'] = '1'
+os.execv(sys.executable, sys.argv[sys.argv.index('--') + 2:])

tests/podman_test.py

@@ -0,0 +1,52 @@
+import os
+import unittest2
+
+import mitogen
+
+import testlib
+
+
+class ConstructorTest(testlib.RouterMixin, testlib.TestCase):
+    def test_okay(self):
+        stub_path = testlib.data_path('stubs/stub-podman.py')
+
+        context = self.router.podman(
+            container='container_name',
+            podman_path=stub_path,
+        )
+        stream = self.router.stream_by_id(context.context_id)
+
+        argv = eval(context.call(os.getenv, 'ORIGINAL_ARGV'))
+        expected_call = [
+            stub_path,
+            'exec',
+            '--interactive',
+            '--',
+            'container_name',
+            stream.conn.options.python_path
+        ]
+        self.assertEquals(argv[:len(expected_call)], expected_call)
+
+        context = self.router.podman(
+            container='container_name',
+            podman_path=stub_path,
+            username='some_user',
+        )
+        stream = self.router.stream_by_id(context.context_id)
+
+        argv = eval(context.call(os.getenv, 'ORIGINAL_ARGV'))
+        expected_call = [
+            stub_path,
+            'exec',
+            '--user=some_user',
+            '--interactive',
+            '--',
+            'container_name',
+            stream.conn.options.python_path
+        ]
+        self.assertEquals(argv[:len(expected_call)], expected_call)
+
+
+
+if __name__ == '__main__':
+    unittest2.main()