Implement pypodman start command

* Improve error messages from argparse Actions
* Silence more pylint errors when supporting a given API
* Refactor BooleanAction to support lower and mixed case input
* Remove spurious print()

Signed-off-by: Jhon Honce <jhonce@redhat.com>

3 files changed, 91 insertions, 16 deletions

diff --git a/contrib/python/pypodman/pypodman/lib/actions/__init__.py b/contrib/python/pypodman/pypodman/lib/actions/__init__.py
index bc863ce6d..c0d77ddb1 100644
--- a/contrib/python/pypodman/pypodman/lib/actions/__init__.py
+++ b/contrib/python/pypodman/pypodman/lib/actions/__init__.py
@@ -22,6 +22,7 @@ from pypodman.lib.actions.rm_action import Rm
 from pypodman.lib.actions.rmi_action import Rmi
 from pypodman.lib.actions.run_action import Run
 from pypodman.lib.actions.search_action import Search
+from pypodman.lib.actions.start_action import Start
 from pypodman.lib.actions.version_action import Version
 
 __all__ = [
@@ -48,5 +49,6 @@ __all__ = [
     'Rmi',
     'Run',
     'Search',
+    'Start',
     'Version',
 ]
diff --git a/contrib/python/pypodman/pypodman/lib/actions/start_action.py b/contrib/python/pypodman/pypodman/lib/actions/start_action.py
new file mode 100644
index 000000000..f312fb3fa
--- /dev/null
+++ b/contrib/python/pypodman/pypodman/lib/actions/start_action.py
@@ -0,0 +1,76 @@
+"""Remote client command for starting containers."""
+import sys
+
+import podman
+from pypodman.lib import AbstractActionBase, BooleanAction
+
+
+class Start(AbstractActionBase):
+    """Class for starting container."""
+
+    @classmethod
+    def subparser(cls, parent):
+        """Add Start command to parent parser."""
+        parser = parent.add_parser('start', help='start container')
+        parser.add_argument(
+            '--attach',
+            '-a',
+            action=BooleanAction,
+            default=False,
+            help="Attach container's STDOUT and STDERR (default: %(default)s)")
+        parser.add_argument(
+            '--detach-keys',
+            metavar='KEY(s)',
+            default=4,
+            help='Override the key sequence for detaching a container.'
+            ' (format: a single character [a-Z] or ctrl-<value> where'
+            ' <value> is one of: a-z, @, ^, [, , or _) (default: ^D)')
+        parser.add_argument(
+            '--interactive',
+            '-i',
+            action=BooleanAction,
+            default=False,
+            help="Attach container's STDIN (default: %(default)s)")
+        # TODO: Implement sig-proxy
+        parser.add_argument(
+            '--sig-proxy',
+            action=BooleanAction,
+            default=False,
+            help="Proxy received signals to the process (default: %(default)s)"
+        )
+        parser.add_argument(
+            'containers',
+            nargs='+',
+            help='containers to start',
+        )
+        parser.set_defaults(class_=cls, method='start')
+
+    def start(self):
+        """Start provided containers."""
+        stdin = sys.stdin if self.opts['interactive'] else None
+        stdout = sys.stdout if self.opts['attach'] else None
+
+        try:
+            for ident in self._args.containers:
+                try:
+                    ctnr = self.client.containers.get(ident)
+                    ctnr.attach(
+                        eot=self.opts['detach_keys'],
+                        stdin=stdin,
+                        stdout=stdout)
+                    ctnr.start()
+                except podman.ContainerNotFound as e:
+                    sys.stdout.flush()
+                    print(
+                        'Container "{}" not found'.format(e.name),
+                        file=sys.stderr,
+                        flush=True)
+                else:
+                    print(ident)
+        except podman.ErrorOccurred as e:
+            sys.stdout.flush()
+            print(
+                '{}'.format(e.reason).capitalize(),
+                file=sys.stderr,
+                flush=True)
+            return 1
diff --git a/contrib/python/pypodman/pypodman/lib/parser_actions.py b/contrib/python/pypodman/pypodman/lib/parser_actions.py
index c10b85495..77ee14761 100644
--- a/contrib/python/pypodman/pypodman/lib/parser_actions.py
+++ b/contrib/python/pypodman/pypodman/lib/parser_actions.py
@@ -37,7 +37,7 @@ class BooleanAction(argparse.Action):
                  const=None,
                  default=None,
                  type=None,
-                 choices=('True', 'False'),
+                 choices=None,
                  required=False,
                  help=None,
                  metavar='{True,False}'):
@@ -59,7 +59,7 @@ class BooleanAction(argparse.Action):
         try:
             val = BooleanValidate()(values)
         except ValueError:
-            parser.error('{} must be True or False.'.format(self.dest))
+            parser.error('"{}" must be True or False.'.format(option_string))
         else:
             setattr(namespace, self.dest, val)
 
@@ -96,7 +96,6 @@ class ChangeAction(argparse.Action):
 
     def __call__(self, parser, namespace, values, option_string=None):
         """Convert and Validate input."""
-        print(self.dest)
         items = getattr(namespace, self.dest, None) or []
         items = copy.copy(items)
 
@@ -105,9 +104,9 @@ class ChangeAction(argparse.Action):
 
         opt, val = values.split('=', 1)
         if opt not in choices:
-            parser.error('{} is not a supported "--change" option,'
+            parser.error('Option "{}" is not supported by argument "{}",'
                          ' valid options are: {}'.format(
-                             opt, ', '.join(choices)))
+                             opt, option_string, ', '.join(choices)))
         items.append(values)
         setattr(namespace, self.dest, items)
 
@@ -127,8 +126,8 @@ class UnitAction(argparse.Action):
                  help=None,
                  metavar='UNIT'):
         """Create UnitAction object."""
-        help = (help or metavar or dest
-                ) + ' (format: <number>[<unit>], where unit = b, k, m or g)'
+        help = (help or metavar or dest)\
+            + ' (format: <number>[<unit>], where unit = b, k, m or g)'
         super().__init__(
             option_strings=option_strings,
             dest=dest,
@@ -148,15 +147,15 @@ class UnitAction(argparse.Action):
         except ValueError:
             if not values[:-1].isdigit():
                 msg = ('{} must be a positive integer,'
-                       ' with optional suffix').format(self.dest)
+                       ' with optional suffix').format(option_string)
                 parser.error(msg)
             if not values[-1] in ('b', 'k', 'm', 'g'):
                 msg = '{} only supports suffices of: b, k, m, g'.format(
-                    self.dest)
+                    option_string)
                 parser.error(msg)
         else:
             if val <= 0:
-                msg = '{} must be a positive integer'.format(self.dest)
+                msg = '{} must be a positive integer'.format(option_string)
                 parser.error(msg)
 
         setattr(namespace, self.dest, values)
@@ -174,19 +173,16 @@ class PositiveIntAction(argparse.Action):
                  type=int,
                  choices=None,
                  required=False,
-                 help=None,
+                 help='Must be a positive integer.',
                  metavar=None):
         """Create PositiveIntAction object."""
-        self.message = '{} must be a positive integer'.format(dest)
-        help = help or self.message
-
         super().__init__(
             option_strings=option_strings,
             dest=dest,
             nargs=nargs,
             const=const,
             default=default,
-            type=int,
+            type=type,
             choices=choices,
             required=required,
             help=help,
@@ -198,7 +194,8 @@ class PositiveIntAction(argparse.Action):
             setattr(namespace, self.dest, values)
             return
 
-        parser.error(self.message)
+        msg = '{} must be a positive integer'.format(option_string)
+        parser.error(msg)
 
 
 class PathAction(argparse.Action):