lxc connection plugin

lib/ansible/plugins/connection/lxc.py

@@ -0,0 +1,215 @@
+# (c) 2015, Joerg Thalheim <joerg@higgsboson.tk>
+#
+# This file is part of Ansible
+#
+# Ansible is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Ansible is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
+
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+import os
+import shutil
+import traceback
+import select
+import fcntl
+import errno
+from ansible import errors
+from ansible import constants as C
+from ansible.plugins.connection import ConnectionBase
+from ansible.utils.unicode import to_bytes
+
+HAS_LIBLXC = False
+try:
+    import lxc as _lxc
+    HAS_LIBLXC = True
+except ImportError:
+    pass
+
+class Connection(ConnectionBase):
+    ''' Local lxc based connections '''
+
+    transport = 'lxc'
+    has_pipelining = True
+    become_methods = frozenset(C.BECOME_METHODS)
+
+    def __init__(self, play_context, new_stdin, *args, **kwargs):
+        super(Connection, self).__init__(play_context, new_stdin, *args, **kwargs)
+
+        self.container_name = self._play_context.remote_addr
+        self.container = None
+
+    def _connect(self):
+        ''' connect to the lxc; nothing to do here '''
+        super(Connection, self)._connect()
+
+        if not HAS_LIBLXC:
+            msg = "lxc bindings for python2 are not installed"
+            raise errors.AnsibleError(msg)
+
+        if self.container:
+            return
+
+        self._display.vvv("THIS IS A LOCAL LXC DIR", host=self.container_name)
+        self.container = _lxc.Container(self.container_name)
+        if self.container.state == "STOPPED":
+            raise errors.AnsibleError("%s is not running" % self.container_name)
+
+    def _communicate(self, pid, in_data, stdin, stdout, stderr):
+        buf = { stdout: [], stderr: [] }
+        read_fds = [stdout, stderr]
+        if in_data:
+            write_fds = [stdin]
+        else:
+            write_fds = []
+        while len(read_fds) > 0 or len(write_fds) > 0:
+            try:
+                ready_reads, ready_writes, _ = select.select(read_fds, write_fds, [])
+            except select.error as e:
+                if e.args[0] == errno.EINTR:
+                    continue
+                raise
+            for fd in ready_writes:
+                in_data = in_data[os.write(fd, in_data):]
+                if len(in_data) == 0:
+                    write_fds.remove(fd)
+            for fd in ready_reads:
+                data = os.read(fd, 32768)
+                if not data:
+                    read_fds.remove(fd)
+                buf[fd].append(data)
+
+        (pid, returncode) = os.waitpid(pid, 0)
+
+        return returncode, b"".join(buf[stdout]), b"".join(buf[stderr])
+
+    def _set_nonblocking(self, fd):
+        flags = fcntl.fcntl(fd, fcntl.F_GETFL) | os.O_NONBLOCK
+        fcntl.fcntl(fd, fcntl.F_SETFL, flags)
+        return fd
+
+    def exec_command(self, cmd, in_data=None, sudoable=False):
+        ''' run a command on the chroot '''
+        super(Connection, self).exec_command(cmd, in_data=in_data, sudoable=sudoable)
+
+        executable = to_bytes(self._play_context.executable, errors='strict')
+        local_cmd = [executable, '-c', to_bytes(cmd, errors='strict')]
+
+        read_stdout, write_stdout = None, None
+        read_stderr, write_stderr = None, None
+        read_stdin, write_stdin   = None, None
+
+        try:
+            read_stdout, write_stdout = os.pipe()
+            read_stderr, write_stderr = os.pipe()
+
+            kwargs = {
+                'stdout': self._set_nonblocking(write_stdout),
+                'stderr': self._set_nonblocking(write_stderr),
+                'env_policy': _lxc.LXC_ATTACH_CLEAR_ENV
+            }
+
+            if in_data:
+                read_stdin, write_stdin = os.pipe()
+                kwargs['stdin'] = self._set_nonblocking(read_stdin)
+
+            self._display.vvv("EXEC %s" % (local_cmd), host=self.container_name)
+            pid = self.container.attach(_lxc.attach_run_command, local_cmd, **kwargs)
+            if pid == -1:
+                msg = "failed to attach to container %s" % self.container_name
+                raise errors.AnsibleError(msg)
+
+            write_stdout = os.close(write_stdout)
+            write_stderr = os.close(write_stderr)
+            if read_stdin:
+                read_stdin = os.close(read_stdin)
+
+            return self._communicate(pid,
+                                     in_data,
+                                     write_stdin,
+                                     read_stdout,
+                                     read_stderr)
+        finally:
+            fds = [read_stdout,
+                   write_stdout,
+                   read_stderr,
+                   write_stderr,
+                   read_stdin,
+                   write_stdin]
+            for fd in fds:
+                if fd:
+                    os.close(fd)
+
+    def put_file(self, in_path, out_path):
+        ''' transfer a file from local to lxc '''
+        super(Connection, self).put_file(in_path, out_path)
+        self._display.vvv("PUT %s TO %s" % (in_path, out_path), host=self.container_name)
+        in_path = to_bytes(in_path, errors='strict')
+        out_path = to_bytes(out_path, errors='strict')
+
+        if not os.path.exists(in_path):
+            msg = "file or module does not exist: %s" % in_path
+            raise errors.AnsibleFileNotFound(msg)
+        try:
+            src_file = open(in_path, "rb")
+        except IOError:
+            traceback.print_exc()
+            raise errors.AnsibleError("failed to open input file to %s" % in_path)
+        try:
+            def write_file(args):
+                with open(out_path, 'wb+') as dst_file:
+                    shutil.copyfileobj(src_file, dst_file)
+            try:
+                self.container.attach_wait(write_file, None)
+            except IOError:
+                traceback.print_exc()
+                msg = "failed to transfer file to %s" % out_path
+                raise errors.AnsibleError(msg)
+        finally:
+            src_file.close()
+
+    def fetch_file(self, in_path, out_path):
+        ''' fetch a file from lxc to local '''
+        super(Connection, self).fetch_file(in_path, out_path)
+        self._display.vvv("FETCH %s TO %s" % (in_path, out_path), host=self.container_name)
+        in_path = to_bytes(in_path, errors='strict')
+        out_path = to_bytes(out_path, errors='strict')
+
+        try:
+            dst_file = open(out_path, "wb")
+        except IOError:
+            traceback.print_exc()
+            msg = "failed to open output file %s" % out_path
+            raise errors.AnsibleError(msg)
+        try:
+            def write_file(args):
+                try:
+                    with open(in_path, 'rb') as src_file:
+                        shutil.copyfileobj(src_file, dst_file)
+                finally:
+                    # this is needed in the lxc child process
+                    # to flush internal python buffers
+                    dst_file.close()
+            try:
+                self.container.attach_wait(write_file, None)
+            except IOError:
+                traceback.print_exc()
+                msg = "failed to transfer file from %s to %s" % (in_path, out_path)
+                raise errors.AnsibleError(msg)
+        finally:
+            dst_file.close()
+
+    def close(self):
+        ''' terminate the connection; nothing to do here '''
+        super(Connection, self).close()
+        self._connected = False

test/integration/test_connection.inventory

@@ -55,6 +55,24 @@ lxd-no-pipelining ansible_ssh_pipelining=false
 ansible_host=centos-7-amd64
 ansible_connection=lxd
 
+[lxc]
+lxc-pipelining    ansible_ssh_pipelining=true
+lxc-no-pipelining ansible_ssh_pipelining=false
+[lxc:vars]
+# 1. install lxc
+# 2. install python2-lxc
+# $ pip install git+https://github.com/lxc/python2-lxc.git
+# 3. create container:
+# $ sudo lxc-create -t download -n centos-7-amd64 -- -d centos -r 7 -a amd64
+# 4. start container:
+# $ sudo lxc-start -n centos-7-amd64 -d
+# 5. run test:
+# $ sudo -E make test_connection TEST_CONNECTION_FILTER=lxc
+# 6. stop container
+# $ sudo lxc-stop -n centos-7-amd64
+ansible_host=centos-7-amd64
+ansible_connection=lxc
+
 [test_default:children]
 local
 chroot

test/units/plugins/connections/test_connection.py

@@ -30,6 +30,7 @@ from ansible.plugins.connection import ConnectionBase
 #from ansible.plugins.connection.funcd import Connection as FuncdConnection
 #from ansible.plugins.connection.jail import Connection as JailConnection
 #from ansible.plugins.connection.libvirt_lxc import Connection as LibvirtLXCConnection
+from ansible.plugins.connection.lxc import Connection as LxcConnection
 from ansible.plugins.connection.local import Connection as LocalConnection
 from ansible.plugins.connection.paramiko_ssh import Connection as ParamikoConnection
 from ansible.plugins.connection.ssh import Connection as SSHConnection
@@ -89,6 +90,9 @@ class TestConnectionBaseClass(unittest.TestCase):
 #    def test_libvirt_lxc_connection_module(self):
 #        self.assertIsInstance(LibvirtLXCConnection(), LibvirtLXCConnection)
 
+    def test_lxc_connection_module(self):
+        self.assertIsInstance(LxcConnection(self.play_context, self.in_stream), LxcConnection)
+
     def test_local_connection_module(self):
         self.assertIsInstance(LocalConnection(self.play_context, self.in_stream), LocalConnection)