Implement connection plugin for podman (#47519)

* new connection plugin: podman

Signed-off-by: Tomas Tomecek <ttomecek@redhat.com>

* podman,conn: utilize remote_user to run commands

Signed-off-by: Tomas Tomecek <ttomecek@redhat.com>

* podman connection: update docs

Co-Authored-By: TomasTomecek <ttomecek@redhat.com>

lib/ansible/plugins/connection/podman.py

@@ -0,0 +1,152 @@
+# Based on the buildah connection plugin
+# Copyright (c) 2018 Ansible Project
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+#
+# Connection plugin to interact with existing podman containers.
+#   https://github.com/containers/libpod
+#
+# Written by: Tomas Tomecek (https://github.com/TomasTomecek)
+
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+import shlex
+import shutil
+import subprocess
+
+from ansible.module_utils._text import to_bytes, to_native
+from ansible.plugins.connection import ConnectionBase, ensure_connect
+
+
+try:
+    from __main__ import display
+except ImportError:
+    from ansible.utils.display import Display
+    display = Display()
+
+
+DOCUMENTATION = """
+    author: Tomas Tomecek (ttomecek@redhat.com)
+    connection: podman
+    short_description: Interact with an existing podman container
+    description:
+        - Run commands or put/fetch files to an existing container using podman tool.
+    version_added: 2.8
+    options:
+      remote_addr:
+        description:
+          - The ID of the container you want to access.
+        default: inventory_hostname
+        vars:
+          - name: ansible_host
+      remote_user:
+        description:
+            - User specified via name or UID which is used to execute commands inside the container. If you
+              specify the user via UID, you must set C(ANSIBLE_REMOTE_TMP) to a path that exits
+               inside the container and is writable by Ansible.
+        ini:
+          - section: defaults
+            key: remote_user
+        env:
+          - name: ANSIBLE_REMOTE_USER
+        vars:
+          - name: ansible_user
+"""
+
+
+# this _has to be_ named Connection
+class Connection(ConnectionBase):
+    """
+    This is a connection plugin for podman. It uses podman binary to interact with the containers
+    """
+
+    # String used to identify this Connection class from other classes
+    transport = 'podman'
+
+    def __init__(self, play_context, new_stdin, *args, **kwargs):
+        super(Connection, self).__init__(play_context, new_stdin, *args, **kwargs)
+
+        self._container_id = self._play_context.remote_addr
+        self._connected = False
+        # container filesystem will be mounted here on host
+        self._mount_point = None
+        self.user = self._play_context.remote_user
+
+    def _podman(self, cmd, cmd_args=None, in_data=None):
+        """
+        run podman executable
+
+        :param cmd: podman's command to execute (str)
+        :param cmd_args: list of arguments to pass to the command (list of str/bytes)
+        :param in_data: data passed to podman's stdin
+        :return: return code, stdout, stderr
+        """
+        local_cmd = ['podman', cmd, self._container_id]
+        if cmd_args:
+            local_cmd += cmd_args
+        local_cmd = [to_bytes(i, errors='surrogate_or_strict') for i in local_cmd]
+
+        display.vvv("RUN %s" % (local_cmd,), host=self._container_id)
+        p = subprocess.Popen(local_cmd, shell=False, stdin=subprocess.PIPE,
+                             stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+
+        stdout, stderr = p.communicate(input=in_data)
+        stdout = to_bytes(stdout, errors='surrogate_or_strict')
+        stderr = to_bytes(stderr, errors='surrogate_or_strict')
+        return p.returncode, stdout, stderr
+
+    def _connect(self):
+        """
+        no persistent connection is being maintained, mount container's filesystem
+        so we can easily access it
+        """
+        super(Connection, self)._connect()
+        rc, self._mount_point, stderr = self._podman("mount")
+        self._mount_point = self._mount_point.strip()
+        display.vvvvv("MOUNTPOINT %s RC %s STDERR %r" % (self._mount_point, rc, stderr))
+        self._connected = True
+
+    @ensure_connect
+    def exec_command(self, cmd, in_data=None, sudoable=False):
+        """ run specified command in a running OCI container using podman """
+        super(Connection, self).exec_command(cmd, in_data=in_data, sudoable=sudoable)
+
+        # shlex.split has a bug with text strings on Python-2.6 and can only handle text strings on Python-3
+        cmd_args_list = shlex.split(to_native(cmd, errors='surrogate_or_strict'))
+        if self.user:
+            cmd_args_list += ["--user", self.user]
+
+        rc, stdout, stderr = self._podman("exec", cmd_args_list)
+
+        display.vvvvv("STDOUT %r STDERR %r" % (stderr, stderr))
+        return rc, stdout, stderr
+
+    def put_file(self, in_path, out_path):
+        """ Place a local file located in 'in_path' inside container at 'out_path' """
+        super(Connection, self).put_file(in_path, out_path)
+        display.vvv("PUT %s TO %s" % (in_path, out_path), host=self._container_id)
+
+        real_out_path = self._mount_point + to_bytes(out_path, errors='surrogate_or_strict')
+        shutil.copyfile(
+            to_bytes(in_path, errors='surrogate_or_strict'),
+            to_bytes(real_out_path, errors='surrogate_or_strict')
+        )
+
+    def fetch_file(self, in_path, out_path):
+        """ obtain file specified via 'in_path' from the container and place it at 'out_path' """
+        super(Connection, self).fetch_file(in_path, out_path)
+        display.vvv("FETCH %s TO %s" % (in_path, out_path), host=self._container_id)
+
+        real_in_path = self._mount_point + to_bytes(in_path, errors='surrogate_or_strict')
+        shutil.copyfile(
+            to_bytes(real_in_path, errors='surrogate_or_strict'),
+            to_bytes(out_path, errors='surrogate_or_strict')
+        )
+
+    def close(self):
+        """ unmount container's filesystem """
+        super(Connection, self).close()
+        # we actually don't need to unmount since the container is mounted anyway
+        # rc, stdout, stderr = self._podman("umount")
+        # display.vvvvv("RC %s STDOUT %r STDERR %r" % (rc, stdout, stderr))
+        self._connected = False

test/integration/targets/connection_podman/aliases

@@ -0,0 +1,2 @@
+non_local
+unsupported

test/integration/targets/connection_podman/posix.sh

@@ -0,0 +1 @@
+../connection_posix/test.sh

test/integration/targets/connection_podman/runme.sh

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+
+set -eux
+
+./posix.sh "$@"
+
+ANSIBLE_REMOTE_TMP="/tmp" ANSIBLE_REMOTE_USER="1000" ./posix.sh "$@"

test/integration/targets/connection_podman/test_connection.inventory

@@ -0,0 +1,15 @@
+[podman]
+podman-container
+[podman:vars]
+# 1. install podman
+# 2. create container:
+#      podman pull python:3-alpine
+#      podman run -d --name podman-container python:3-alpine sleep 999999
+# 3. run test:
+#      ./bin/ansible-test integration connection_podman
+# 6. remove container
+#      podman stop podman-container
+#      podman rm podman-container
+ansible_host=podman-container
+ansible_connection=podman
+ansible_python_interpreter=/usr/local/bin/python