Initial commit: add arguments parsing and minimal shell

.gitignore

+*.sw?
+*.pyc

circle

+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+# Copyright 2017 Budapest University of Technology and Economics (BME IK)
+#
+# This file is part of CIRCLE Cloud.
+#
+# CIRCLE 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.
+#
+# CIRCLE 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 CIRCLE.  If not, see <http://www.gnu.org/licenses/>.
+
+
+import argparse
+from shell import OCCIShell
+from parsers import VMParser, TemplateParser, NetworkParser
+
+top_parser = argparse.ArgumentParser()
+group = top_parser.add_mutually_exclusive_group()
+group.add_argument("--json", action="store_true",
+                   help="Show output in JSON format.")
+group.add_argument("--pretty-json", action="store_true",
+                   help="Show output in prettified JSON format.")
+top_parser.add_argument("command", nargs="?", default="shell")
+top_parser.add_argument("command_args", type=unicode, nargs=argparse.REMAINDER)
+
+args = top_parser.parse_args()
+
+parsers = {
+    "vm": VMParser(),
+    "template": TemplateParser(),
+    "network": NetworkParser(),
+}
+
+if args.command == "shell":
+    try:
+        OCCIShell().cmdloop()
+    except KeyboardInterrupt:  # Ctrl + C
+        print("")
+        pass
+else:
+    parser = parsers.get(args.command)
+    if parser:
+        parser.parse_args(args.command_args)
+    else:
+        top_parser.print_usage()

parsers.py

+# -*- coding: utf-8 -*-
+# Copyright 2017 Budapest University of Technology and Economics (BME IK)
+#
+# This file is part of CIRCLE Cloud.
+#
+# CIRCLE 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.
+#
+# CIRCLE 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 CIRCLE.  If not, see <http://www.gnu.org/licenses/>.
+
+
+import argparse
+
+
+class ResourceParser(argparse.ArgumentParser):
+    description = None
+    name = None
+
+    def __init__(self, *args, **kwargs):
+        super(ResourceParser, self).__init__(
+            add_help=False, description=self.description, prog=self.name,
+            *args, **kwargs)
+
+        self.subparsers = self.add_subparsers(
+            parser_class=argparse.ArgumentParser)
+        list_parser = self.subparsers.add_parser("list")
+        list_parser.add_argument("--filter", type=unicode)
+
+
+class VMParser(ResourceParser):
+    description = "VM operations"
+    name = "vm"
+
+    def __init__(self, *args, **kwargs):
+        super(VMParser, self).__init__(*args, **kwargs)
+        commands = ("start", "stop", "forced_start", "forced_stop",
+                    "reboot", "forced_reboot", "destroy", "renew")
+        for cmd in commands:
+            sub_parser = self.subparsers.add_parser(cmd)
+            self.add_id_arguments(sub_parser)
+
+        create_parser = self.subparsers.add_parser("create")
+        create_group = create_parser.add_mutually_exclusive_group(required=True)
+        create_group.add_argument("-t", "--template-id", type=int)
+        create_group.add_argument("--template-name", type=int)
+        self.add_vm_arguments(create_parser)
+
+        modify_parser = self.subparsers.add_parser("modify")
+        self.add_id_arguments(modify_parser)
+        self.add_vm_arguments(modify_parser)
+
+        self.add_disk_parser()
+        self.add_nic_parser()
+
+    def add_vm_arguments(self, parser):
+        parser.add_argument("-n", "--vm-name", type=unicode)
+        parser.add_argument("-c", "--cpu", type=int)
+        parser.add_argument("-m", "--memory", type=int)
+        parser.add_argument("-p", "--priotiry", type=unicode,
+            choices=("idle", "normal", "server", "realtime"))
+
+    def add_id_arguments(self, parser, name=None):
+        prefix = name + "-" if name else ""
+        group = parser.add_mutually_exclusive_group(required=True)
+        group.add_argument("--%sname" % prefix, type=unicode)
+        group.add_argument("--%sid" % prefix, type=int)
+
+    def add_subresource_parser(self, name):
+        parser = self.subparsers.add_parser(name)
+        parsers = parser.add_subparsers()
+
+        list_parser = parsers.add_parser("list")
+        list_parser.add_argument("--filter", type=unicode)
+
+        destroy_parser = parsers.add_parser("destroy")
+        self.add_id_arguments(destroy_parser, name)
+        show_parser = parsers.add_parser("show")
+        self.add_id_arguments(show_parser, name)
+
+        return parsers
+
+    def add_disk_parser(self):
+        parsers = self.add_subresource_parser("disk")
+        create_parser = parsers.add_parser("create")
+        self.add_id_arguments(create_parser, "vm")
+        create_parser.add_argument("--disk-name", type=unicode)
+        create_parser.add_argument("--size", type=int)
+
+    def add_nic_parser(self):
+        parsers = self.add_subresource_parser("nic")
+        create_parser = parsers.add_parser("create")
+        self.add_id_arguments(create_parser, "vm")
+        self.add_id_arguments(create_parser, "network")
+
+
+class TemplateParser(ResourceParser):
+    description = "Template operations"
+    name = "template"
+
+
+class NetworkParser(ResourceParser):
+    description = "Network operations"
+    name = "network"

shell.py

+# -*- coding: utf-8 -*-
+# Copyright 2017 Budapest University of Technology and Economics (BME IK)
+#
+# This file is part of CIRCLE Cloud.
+#
+# CIRCLE 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.
+#
+# CIRCLE 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 CIRCLE.  If not, see <http://www.gnu.org/licenses/>.
+
+
+import cmd
+from parsers import VMParser, NetworkParser, TemplateParser
+
+
+def parser(parser_class):
+    def top_wrapper(func):
+        def wrapper(self, arg):
+            try:
+                args = parser_class().parse_args(arg.split())
+                return func(self, args)
+            except SystemExit:
+                pass
+        return wrapper
+    return top_wrapper
+
+
+class OCCIShell(cmd.Cmd):
+    intro = ('Wellcome to the CIRCLE cloud shell.'
+             ' Type help or ? to list commands.\n')
+
+    prompt = '(CIRCLE) '
+
+    def do_print(self, arg):
+        print(arg)
+
+    @parser(VMParser)
+    def do_vm(self, arg):
+        print("vm %s" % unicode(arg))
+
+    @parser(TemplateParser)
+    def do_template(self, arg):
+        print("template %s" % unicode(arg))
+
+    @parser(NetworkParser)
+    def do_network(self, arg):
+        print("network %s" % unicode(arg))
+
+    def do_exit(self, arg):
+        exit()
+
+    def do_quit(self, arg):
+        exit()
+
+    def precmd(self, line):
+        if line == "EOF":  # Ctrl + D
+            print("")
+            exit()
+        return line