Implemented a login subcommand (#711)

* Cleaned up interpolation coverage

When moving code over from Docker, there was uncovered code.
Deleted the code, since I don't see a valid reason we would
encounter the raise.

* Implemented a login subcommand

Ported v1 login to v2.

Fixes: #704

doc/source/usage.rst

@@ -10,7 +10,7 @@ Install Molecule using pip:
 
   $ pip install molecule --pre
 
-.. warn::
+.. warning::
 
     This install method is not yet available.  We will cut a pre-release
     candidate once ready.
@@ -195,6 +195,13 @@ Lint
    :undoc-members:
    :members: execute
 
+Login
+^^^^^
+
+.. autoclass:: molecule.command.login.Login
+   :undoc-members:
+   :members: execute
+
 Status
 ^^^^^^
 

molecule/command/__init__.py

@@ -31,7 +31,7 @@
 from molecule.command import idempotence  # noqa
 from molecule.command import init  # noqa
 from molecule.command import lint  # noqa
-#  from molecule.command import login  # noqa
+from molecule.command import login  # noqa
 from molecule.command import status  # noqa
 from molecule.command import syntax  # noqa
 from molecule.command import test  # noqa

molecule/command/login.py

@@ -0,0 +1,115 @@
+#  Copyright (c) 2015-2017 Cisco Systems, Inc.
+#
+#  Permission is hereby granted, free of charge, to any person obtaining a copy
+#  of this software and associated documentation files (the "Software"), to
+#  deal in the Software without restriction, including without limitation the
+#  rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+#  sell copies of the Software, and to permit persons to whom the Software is
+#  furnished to do so, subject to the following conditions:
+#
+#  The above copyright notice and this permission notice shall be included in
+#  all copies or substantial portions of the Software.
+#
+#  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+#  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+#  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+#  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+#  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+#  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+#  DEALINGS IN THE SOFTWARE.
+
+import fcntl
+import os
+import pexpect
+import signal
+import struct
+import sys
+import termios
+
+import click
+
+from molecule import util
+from molecule.command import base
+
+
+class Login(base.Base):
+    def execute(self):
+        """
+        Execute the actions necessary to perform a `molecule login` and
+        returns None.
+
+        >>> molecule login --host hotname --scenario-name foo
+
+        :return: None
+        """
+        if not self._config.state.created:
+            msg = 'Instances not created.  Please create instances first.'
+            util.print_error(msg)
+            util.sysexit()
+
+        hosts = [d['name'] for d in self._config.platforms_with_scenario_name]
+        hostname = self._get_hostname(hosts)
+        self._get_login(hostname)
+
+    def _get_hostname(self, hosts):
+        hostname = self._config.command_args.get('host')
+        match = [x for x in hosts if x.startswith(hostname)]
+        if len(match) == 0:
+            msg = ("There are no hosts that match '{}'.  You "
+                   'can only login to valid hosts.').format(hostname)
+            util.print_error(msg)
+            util.sysexit()
+        elif len(match) != 1:
+            # If there are multiple matches, but one of them is an exact string
+            # match, assume this is the one they're looking for and use it.
+            if hostname in match:
+                match = [hostname, ]
+            else:
+                msg = ("There are {} hosts that match '{}'. You "
+                       'can only login to one at a time.\n\n'
+                       'Available hosts:\n{}'.format(
+                           len(match), hostname, '\n'.join(sorted(hosts))))
+                util.print_error(msg)
+                util.sysexit()
+
+        return match[0]
+
+    def _get_login(self, hostname):  # pragma: no cover
+        login_cmd = self._config.driver.login_cmd_template
+        login_args = self._config.driver.login_args(hostname)
+
+        lines, columns = os.popen('stty size', 'r').read().split()
+        dimensions = (int(lines), int(columns))
+        self._pt = pexpect.spawn(
+            '/usr/bin/env ' + login_cmd.format(*login_args),
+            dimensions=dimensions)
+        signal.signal(signal.SIGWINCH, self._sigwinch_passthrough)
+        self._pt.interact()
+
+    def _sigwinch_passthrough(self, sig, data):  # pragma: no cover
+        TIOCGWINSZ = 1074295912  # assume
+        if 'TIOCGWINSZ' in dir(termios):
+            TIOCGWINSZ = termios.TIOCGWINSZ
+        s = struct.pack('HHHH', 0, 0, 0, 0)
+        a = struct.unpack('HHHH',
+                          fcntl.ioctl(sys.stdout.fileno(), TIOCGWINSZ, s))
+        self._pt.setwinsize(a[0], a[1])
+
+
+@click.command()
+@click.pass_context
+@click.option('--host', required=True, help='Host to access.')
+@click.option(
+    '--scenario-name', required=True, help='Name of the scenario to target.')
+def login(ctx, host, scenario_name):  # pragma: no cover
+    """ Log in to one instance. """
+    args = ctx.obj.get('args')
+    command_args = {
+        'subcommand': __name__,
+        'host': host,
+        'scenario_name': scenario_name
+    }
+
+    for config in base.get_configs(args, command_args):
+        l = Login(config)
+        l.execute()

molecule/driver/base.py

@@ -36,13 +36,40 @@ def __init__(self, config):
     @abc.abstractproperty
     def testinfra_options(self):
         """
-        Returns the kwargs used when invoking the testinfra validator, and
-        returns a dict.
+        Returns a Testinfra specific options dict.
 
         :returns: dict
         """
         pass  # pragma: no cover
 
+    @abc.abstractproperty
+    def connection_options(self):
+        """
+        Returns a driver specific connection options dict.
+
+        :returns: str
+        """
+        pass  # pragma: no cover
+
+    @abc.abstractproperty
+    def login_cmd_template(self):
+        """
+        Returns the command string to login to a host.
+
+        :returns: str
+        """
+        pass  # pragma: no cover
+
+    @abc.abstractmethod
+    def login_args(self, instance_name):
+        """
+        Returns the arguments used in the login command and returns a list.
+
+        :param instance_name: A string containing the instance to login to.
+        :returns: list
+        """
+        pass  # pragma: no cover
+
     @abc.abstractmethod
     def status(self):
         """

molecule/driver/dockr.py

@@ -48,22 +48,19 @@ def __init__(self, config):
 
     @property
     def testinfra_options(self):
-        """
-        Returns a Testinfra specific options dict.
-
-        :returns: dict
-        """
         return {'connection': 'docker'}
 
     @property
     def connection_options(self):
-        """
-        Returns a driver specific connection options dict.
-
-        :returns: str
-        """
         return {'ansible_connection': 'docker'}
 
+    @property
+    def login_cmd_template(self):
+        return 'docker exec -ti {} bash'
+
+    def login_args(self, instance):
+        return [instance]
+
     def status(self):
         Status = collections.namedtuple('Status', ['name', 'state', 'driver'])
         status_list = []

molecule/interpolation.py

@@ -83,7 +83,5 @@ def convert(mo):
                 return self.delimiter
             if mo.group('invalid') is not None:
                 self._invalid(mo)
-            raise ValueError('Unrecognized named group in pattern',
-                             self.pattern)
 
         return self.pattern.sub(convert, self.template)

molecule/shell.py

@@ -49,7 +49,7 @@ def cli(ctx, debug):  # pragma: no cover
 cli.add_command(command.idempotence.idempotence)
 cli.add_command(command.init.init)
 cli.add_command(command.lint.lint)
-#  cli.add_command(command.login.login)
+cli.add_command(command.login.login)
 cli.add_command(command.status.status)
 cli.add_command(command.syntax.syntax)
 cli.add_command(command.test.test)

test/functional/test_docker.py

@@ -21,6 +21,7 @@
 import os
 import re
 
+import pexpect
 import pytest
 import sh
 
@@ -88,6 +89,18 @@ def test_command_lint(with_scenario):
     sh.molecule('lint')
 
 
+@pytest.mark.parametrize(
+    'with_scenario', ['docker'], indirect=['with_scenario'])
+def test_command_login(with_scenario):
+    sh.molecule('create')
+
+    child = pexpect.spawn(
+        'molecule login --host instance  --scenario-name default')
+    child.expect('.*instance-[12].*')
+    # If the test returns and doesn't hang it succeeded.
+    child.sendline('exit')
+
+
 @pytest.mark.parametrize(
     'with_scenario', ['docker'], indirect=['with_scenario'])
 def test_command_status(with_scenario):

test/unit/command/test_login.py

@@ -0,0 +1,122 @@
+#  Copyright (c) 2015-2017 Cisco Systems, Inc.
+#
+#  Permission is hereby granted, free of charge, to any person obtaining a copy
+#  of this software and associated documentation files (the "Software"), to
+#  deal in the Software without restriction, including without limitation the
+#  rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+#  sell copies of the Software, and to permit persons to whom the Software is
+#  furnished to do so, subject to the following conditions:
+#
+#  The above copyright notice and this permission notice shall be included in
+#  all copies or substantial portions of the Software.
+#
+#  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+#  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+#  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+#  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+#  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+#  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+#  DEALINGS IN THE SOFTWARE.
+
+import pytest
+
+from molecule import config
+from molecule.command import login
+
+
+@pytest.fixture
+def login_instance(molecule_file, platforms_data):
+    configs = [platforms_data]
+    c = config.Config(
+        molecule_file,
+        args={},
+        command_args={'host': 'instance-1'},
+        configs=configs)
+    c.state.change_state('created', True)
+
+    return login.Login(c)
+
+
+def test_execute(mocker, login_instance):
+    m = mocker.patch('molecule.command.login.Login._get_login')
+    login_instance.execute()
+
+    m.assert_called_once_with('instance-1-default')
+
+
+def test_execute_raises_when_not_converged(patched_print_error,
+                                           login_instance):
+    login_instance._config.state.change_state('created', False)
+    with pytest.raises(SystemExit) as e:
+        login_instance.execute()
+
+    assert 1 == e.value.code
+
+    msg = 'Instances not created.  Please create instances first.'
+    patched_print_error.assert_called_with(msg)
+
+
+def test_get_hostname_does_not_match(molecule_file, patched_print_error):
+    c = config.Config(molecule_file, command_args={'host': 'invalid'})
+    l = login.Login(c)
+    hosts = ['instance-1']
+
+    with pytest.raises(SystemExit) as e:
+        l._get_hostname(hosts)
+
+    assert 1 == e.value.code
+
+    msg = ("There are no hosts that match 'invalid'.  You "
+           'can only login to valid hosts.')
+    patched_print_error.assert_called_once_with(msg)
+
+
+def test_get_hostname_exact_match_with_one_host(molecule_file):
+    c = config.Config(molecule_file, command_args={'host': 'instance-1'})
+    l = login.Login(c)
+    hosts = ['instance-1']
+
+    assert 'instance-1' == l._get_hostname(hosts)
+
+
+def test_get_hostname_partial_match_with_one_host(molecule_file):
+    c = config.Config(molecule_file, command_args={'host': 'inst'})
+    l = login.Login(c)
+    hosts = ['instance-1']
+
+    assert 'instance-1' == l._get_hostname(hosts)
+
+
+def test_get_hostname_exact_match_with_multiple_hosts(molecule_file):
+    c = config.Config(molecule_file, command_args={'host': 'instance-1'})
+    l = login.Login(c)
+    hosts = ['instance-1', 'instance-2']
+
+    assert 'instance-1' == l._get_hostname(hosts)
+
+
+def test_get_hostname_partial_match_with_multiple_hosts(molecule_file):
+    c = config.Config(molecule_file, command_args={'host': 'foo'})
+    l = login.Login(c)
+    hosts = ['foo', 'fooo']
+
+    assert 'foo' == l._get_hostname(hosts)
+
+
+def test_get_hostname_partial_match_with_multiple_hosts_raises(
+        molecule_file, patched_print_error):
+    c = config.Config(molecule_file, command_args={'host': 'inst'})
+    l = login.Login(c)
+    hosts = ['instance-1', 'instance-2']
+
+    with pytest.raises(SystemExit) as e:
+        l._get_hostname(hosts)
+
+    assert 1 == e.value.code
+
+    msg = ("There are 2 hosts that match 'inst'. "
+           'You can only login to one at a time.\n\n'
+           'Available hosts:\n'
+           'instance-1\n'
+           'instance-2')
+    patched_print_error.assert_called_once_with(msg)