adding Google Compute Engine modules and inventory plugin

library/cloud/gce_net

+#!/usr/bin/python
+# Copyright 2013 Google Inc.
+#
+# 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/>.
+
+DOCUMENTATION = '''
+---
+module: gce_net
+short_description: create/destroy GCE networks and firewall rules
+description:
+    - This module can create and destroy Google Compue Engine networks and
+      firewall rules U(https://developers.google.com/compute/docs/networking).
+      The I(name) parameter is reserved for referencing a network while the
+      I(fwname) parameter is used to reference firewall rules.
+      IPv4 Address ranges must be specified using the CIDR
+      U(http://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing) format.
+      Full install/configuration instructions for the gce* modules can
+      be found in the comments of ansible/test/gce_tests.py.
+options:
+  allowed:
+    description:
+      - the protocol:ports to allow ('tcp:80' or 'tcp:80,443' or 'tcp:80-800')
+    required: false
+    default: null 
+    aliases: []
+  ipv4_range:
+    description:
+      - the IPv4 address range in CIDR notation for the network
+    required: false
+    aliases: ['cidr']
+  fwname:
+    description:
+      - name of the firewall rule
+    required: false
+    default: null
+    aliases: ['fwrule']
+  name:
+    description:
+      - name of the network
+    required: false
+    default: null
+    aliases: []
+  src_range:
+    description:
+      - the source IPv4 address range in CIDR notation
+    required: false
+    default: null
+    aliases: ['src_cidr']
+  src_tags:
+    description:
+      - the source instance tags for creating a firewall rule
+    required: false
+    default: null
+    aliases: []
+  state:
+    description:
+      - desired state of the persistent disk
+    required: false
+    default: "present"
+    choices: ["active", "present", "absent", "deleted"]
+    aliases: []
+
+requirements: [ "libcloud" ]
+author: Eric Johnson <erjohnso@google.com>
+'''
+
+EXAMPLES = '''
+# Simple example of creating a new network
+- local_action: 
+    module: gce_net
+    name: privatenet
+    ipv4_range: '10.240.16.0/24'
+   
+# Simple example of creating a new firewall rule
+- local_action: 
+    module: gce_net
+    name: privatenet
+    allowed: tcp:80,8080
+    src_tags: ["web", "proxy"]
+
+'''
+
+import sys
+
+try:                                                                            
+    from libcloud.compute.types import Provider                                 
+    from libcloud.compute.providers import get_driver                           
+    from libcloud.common.google import GoogleBaseError, QuotaExceededError, \
+            ResourceExistsError, ResourceNotFoundError
+    _ = Provider.GCE                                                            
+except ImportError:                                                             
+    print("failed=True " + \
+            "msg='libcloud with GCE support required for this module.'")
+    sys.exit(1)                                                                 
+                                                                                
+# Load in the libcloud secrets file                                             
+try:                                                                            
+    import secrets                                                              
+except ImportError:                                                             
+    secrets = None                                                              
+ARGS = getattr(secrets, 'GCE_PARAMS', ())                                       
+KWARGS = getattr(secrets, 'GCE_KEYWORD_PARAMS', {})                             
+
+if not ARGS or not KWARGS.has_key('project'):
+    print("failed=True msg='Missing GCE connection " + \
+            "parameters in libcloud secrets file.'")
+    sys.exit(1)
+
+def unexpected_error_msg(error):
+    """Format error string based on passed in error."""
+    msg='Unexpected response: HTTP return_code['
+    msg+='%s], API error code[%s] and message: %s' % (
+            error.http_code, error.code, str(error.value))
+    return msg
+
+def format_allowed(allowed):
+    """Format the 'allowed' value so that it is GCE compatible."""
+    if allowed.count(":") == 0:
+        protocol = allowed
+        ports = []
+    elif allowed.count(":") == 1:
+        protocol, ports = allowed.split(":")
+    else:
+        return []
+    if ports.count(","):
+        ports = ports.split(",")
+    else:
+        ports = [ports]
+    return_val = {"IPProtocol": protocol}
+    if ports:
+        return_val["ports"] = ports
+    return [return_val]
+
+
+def main():
+    module = AnsibleModule(
+        argument_spec = dict(
+            allowed = dict(),
+            ipv4_range = dict(),
+            fwname = dict(),
+            name = dict(),
+            src_range = dict(),
+            src_tags = dict(type='list'),
+            state = dict(default='present'),
+        )
+    )
+
+    allowed = module.params.get('allowed')
+    ipv4_range = module.params.get('ipv4_range')
+    fwname = module.params.get('fwname')
+    name = module.params.get('name')
+    src_range = module.params.get('src_range')
+    src_tags = module.params.get('src_tags')
+    state = module.params.get('state')
+
+    try:
+        gce = get_driver(Provider.GCE)(*ARGS, **KWARGS)
+    except Exception as e:
+        module.fail_json(msg=unexpected_error_msg(e), changed=False)
+
+    changed = False
+    json_output = {'state': state}
+
+    if state in ['active', 'present']:
+        network = None
+        try:
+            network = gce.ex_get_network(name)
+            json_output['name'] = name
+            json_output['ipv4_range'] = network.cidr
+        except ResourceNotFoundError:
+            pass
+        except Exception as e:
+            module.fail_json(msg=unexpected_error_msg(e), changed=False)
+
+        # user wants to create a new network that doesn't yet exist
+        if name and not network:
+            if not ipv4_range:
+                module.fail_json(msg="Missing required 'ipv4_range' parameter",
+                    changed=False)
+
+            try:
+                network = gce.ex_create_network(name, ipv4_range)
+                json_output['name'] = name
+                json_output['ipv4_range'] = ipv4_range
+                changed = True
+            except Exception as e:
+                module.fail_json(msg=unexpected_error_msg(e), changed=False)
+
+        if fwname:
+            # user creating a firewall rule
+            if not allowed and not src_range and not src_tags:
+                if changed and network:
+                    module.fail_json(
+                        msg="Network created, but missing required " + \
+                        "firewall rule parameter(s)", changed=True)
+                module.fail_json(
+                    msg="Missing required firewall rule parameter(s)",
+                    changed=False)
+
+            allowed_list = format_allowed(allowed)
+
+            try:
+                gce.ex_create_firewall(fwname, allowed_list, network=name,
+                        source_ranges=src_range, source_tags=src_tags)
+                changed = True
+            except ResourceExistsError:
+                pass
+            except Exception as e:
+                module.fail_json(msg=unexpected_error_msg(e), changed=False)
+
+            json_output['fwname'] = fwname
+            json_output['allowed'] = allowed
+            json_output['src_range'] = src_range
+            json_output['src_tags'] = src_tags
+
+    if state in ['absent', 'deleted']:
+        if fwname:
+            json_output['fwname'] = fwname
+            fw = None
+            try:
+                fw = gce.ex_get_firewall(fwname)
+            except ResourceNotFoundError:
+                pass
+            except Exception as e:
+                module.fail_json(msg=unexpected_error_msg(e), changed=False)
+            if fw:
+                gce.ex_destroy_firewall(fw)
+                changed = True
+        if name:
+            json_output['name'] = name
+            network = None
+            try:
+                network = gce.ex_get_network(name)
+#                json_output['d1'] = 'found network name %s' % name
+            except ResourceNotFoundError:
+#                json_output['d2'] = 'not found network name %s' % name
+                pass
+            except Exception as e:
+#                json_output['d3'] = 'error with %s' % name
+                module.fail_json(msg=unexpected_error_msg(e), changed=False)
+            if network:
+#                json_output['d4'] = 'deleting %s' % name
+                gce.ex_destroy_network(network)
+#                json_output['d5'] = 'deleted %s' % name
+                changed = True
+
+    json_output['changed'] = changed
+    print json.dumps(json_output)
+    sys.exit(0)
+
+# this is magic, see lib/ansible/module_common.py
+#<<INCLUDE_ANSIBLE_MODULE_COMMON>>
+
+main()

library/cloud/gce_pd

+#!/usr/bin/python
+# Copyright 2013 Google Inc.
+#
+# 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/>.
+
+DOCUMENTATION = '''
+---
+module: gce_pd
+short_description: utilize GCE persistent disk resources
+description:
+    - This module can create and destroy unformatted GCE persistent disks
+      U(https://developers.google.com/compute/docs/disks#persistentdisks).
+      It also supports attaching and detaching disks from running instances
+      but does not support creating boot disks from images or snapshots.  The
+      'gce' module supports creating instances with boot disks.
+      Full install/configuration instructions for the gce* modules can
+      be found in the comments of ansible/test/gce_tests.py.
+options:
+  detach_only:
+    description:
+      - do not destroy the disk, merely detach it from an instance
+    required: false
+    default: "no"
+    choices: ["yes", "no"]
+    aliases: []
+  instance_name:
+    description:
+      - instance name if you wish to attach or detach the disk 
+    required: false
+    default: null 
+    aliases: []
+  mode:
+    description:
+      - GCE mount mode of disk, READ_ONLY (default) or READ_WRITE
+    required: false
+    default: "READ_ONLY" 
+    choices: ["READ_WRITE", "READ_ONLY"]
+    aliases: []
+  name:
+    description:
+      - name of the disk
+    required: true
+    default: null 
+    aliases: []
+  size_gb:
+    description:
+      - whole integer size of disk (in GB) to create, default is 10 GB
+    required: false
+    default: 10
+    aliases: []
+  state:
+    description:
+      - desired state of the persistent disk
+    required: false
+    default: "present"
+    choices: ["active", "present", "absent", "deleted"]
+    aliases: []
+  zone:
+    description:
+      - zone in which to create the disk
+    required: false
+    default: "us-central1-b"
+    aliases: []
+
+requirements: [ "libcloud" ]
+author: Eric Johnson <erjohnso@google.com>
+'''
+
+EXAMPLES = '''
+# Simple attachment action to an existing instance
+- local_action: 
+    module: gce_pd 
+    instance_name: notlocalhost
+    size_gb: 5 
+    name: pd
+'''
+
+import sys
+
+try:                                                                            
+    from libcloud.compute.types import Provider                                 
+    from libcloud.compute.providers import get_driver                           
+    from libcloud.common.google import GoogleBaseError, QuotaExceededError, \
+            ResourceExistsError, ResourceNotFoundError, ResourceInUseError
+    _ = Provider.GCE                                                            
+except ImportError:                                                             
+    print("failed=True " + \
+        "msg='libcloud with GCE support is required for this module.'")
+    sys.exit(1)                                                                 
+                                                                                
+# Load in the libcloud secrets file                                             
+try:                                                                            
+    import secrets                                                              
+except ImportError:                                                             
+    secrets = None                                                              
+ARGS = getattr(secrets, 'GCE_PARAMS', ())                                       
+KWARGS = getattr(secrets, 'GCE_KEYWORD_PARAMS', {})                             
+
+if not ARGS or not KWARGS.has_key('project'):
+    print("failed=True " + \
+        "msg='Missing GCE connection parameters in libcloud secrets file.'")
+    sys.exit(1)
+
+def unexpected_error_msg(error):
+    msg='Unexpected response: HTTP return_code['
+    msg+='%s], API error code[%s] and message: %s' % (
+        error.http_code, error.code, str(error.value))
+    return msg
+
+def main():
+    module = AnsibleModule(
+        argument_spec = dict(
+            detach_only = dict(choice=BOOLEANS),
+            instance_name = dict(),
+            mode = dict(default='READ_ONLY',
+                choices=['READ_WRITE', 'READ_ONLY']),
+            name = dict(required=True),
+            size_gb = dict(default=10),
+            state = dict(default='present'),
+            zone = dict(default='us-central1-b'),
+        )
+    )
+
+    detach_only = module.params.get('detach_only')
+    instance_name = module.params.get('instance_name')
+    mode = module.params.get('mode')
+    name = module.params.get('name')
+    size_gb = module.params.get('size_gb')
+    state = module.params.get('state')
+    zone = module.params.get('zone')
+
+    if detach_only and not instance_name:
+        module.fail_json(
+            msg='Must specify an instance name when detaching a disk',
+            changed=False)
+
+    try:
+        gce = get_driver(Provider.GCE)(*ARGS, datacenter=zone, **KWARGS)
+    except Exception as e:
+        module.fail_json(msg=unexpected_error_msg(e), changed=False)
+
+    disk = inst = None
+    changed = is_attached = False
+
+    json_output = { 'name': name, 'zone': zone, 'state': state }
+    if detach_only:
+        json_output['detach_only'] = True
+        json_output['detached_from_instance'] = instance_name
+
+    if instance_name:
+        # user wants to attach/detach from an existing instance
+        try:
+            inst = gce.ex_get_node(instance_name, zone)
+            # is the disk attached?
+            for d in inst.extra['disks']:
+                if d['deviceName'] == name:
+                    is_attached = True
+                    json_output['attached_mode'] = d['mode']
+                    json_output['attached_to_instance'] = inst.name
+        except:
+            pass
+
+    # find disk if it already exists
+    try:
+        disk = gce.ex_get_volume(name)
+        json_output['size_gb'] = int(disk.size)
+    except ResourceNotFoundError:
+        pass
+    except Exception as e:
+        module.fail_json(msg=unexpected_error_msg(e), changed=False)
+
+    # user wants a disk to exist.  If "instance_name" is supplied the user
+    # also wants it attached
+    if state in ['active', 'present']:
+
+        if not size_gb:
+            module.fail_json(msg="Must supply a size_gb", changed=False)
+        try:
+            size_gb = int(round(float(size_gb)))
+            if size_gb < 1: raise Exception
+        except:        
+            module.fail_json(msg="Must supply a size_gb larger than 1 GB",
+                    changed=False)
+
+        if instance_name and inst is None:
+            module.fail_json(msg='Instance %s does not exist in zone %s' % (
+                    instance_name, zone), changed=False)
+
+        if not disk:
+            try:
+                disk = gce.create_volume(size_gb, name, location=zone)
+            except ResourceExistsError:
+                pass
+            except QuotaExceededError:
+                module.fail_json(msg='Requested disk size exceeds quota',
+                        changed=False)
+            except Exception as e:
+                module.fail_json(msg=unexpected_error_msg(e), changed=False)
+            json_output['size_gb'] = size_gb
+            changed = True
+        if inst and not is_attached:
+            try:
+                gce.attach_volume(inst, disk, device=name, ex_mode=mode)
+            except Exception as e:
+                module.fail_json(msg=unexpected_error_msg(e), changed=False)
+            json_output['attached_to_instance'] = inst.name
+            json_output['attached_mode'] = mode
+            changed = True
+
+    # user wants to delete a disk (or perhaps just detach it).
+    if state in ['absent', 'deleted'] and disk:
+
+        if inst and is_attached:
+            try:
+                gce.detach_volume(disk, ex_node=inst)
+            except Exception as e:
+                module.fail_json(msg=unexpected_error_msg(e), changed=False)
+            changed = True
+        if not detach_only:
+            try:
+                gce.destroy_volume(disk)
+            except ResourceInUseError as e:
+                module.fail_json(msg=str(e.value), changed=False)
+            except Exception as e:
+                module.fail_json(msg=unexpected_error_msg(e), changed=False)
+            changed = True
+
+    json_output['changed'] = changed
+    print json.dumps(json_output)
+    sys.exit(0)
+
+# this is magic, see lib/ansible/module_common.py
+#<<INCLUDE_ANSIBLE_MODULE_COMMON>>
+
+main()

plugins/inventory/gce.ini

+#!/usr/bin/python
+# Copyright 2013 Google Inc.
+#
+# 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/>.
+
+# The GCE inventory script has the following dependencies:
+#   1. A valid Google Cloud Platform account with Google Compute Engine
+#      enabled.  See https://cloud.google.com
+#   2. An OAuth2 Service Account flow should be enabled.  This will generate
+#      a private key file that the inventory script will use for API request
+#      authorization.  See https://developers.google.com/accounts/docs/OAuth2
+#   3. Convert the private key from PKCS12 to PEM format
+#      $ openssl pkcs12 -in pkey.pkcs12 -passin pass:notasecret \
+#      > -nodes -nocerts | openssl rsa -out pkey.pem
+#   4. The libcloud (>=0.13.3) python libray.  See http://libcloud.apache.org
+#
+# (See ansible/test/gce_tests.py comments for full install instructions)
+#
+# Author: Eric Johnson <erjohnso@google.com>
+
+[gce]
+# GCE Service Account configuration information can be stored in the
+# libcloud 'secrets.py' file.  Ideally, the 'secrets.py' file will already
+# exist in your PYTHONPATH and be picked up automatically with an import
+# statement in the inventory script.  However, you can specify an absolute
+# path to the secrets.py file with 'libcloud_secrets' parameter.
+libcloud_secrets = 
+
+# If you are not going to use a 'secrets.py' file, you can set the necessary
+# authorization parameters here.
+gce_service_account_email_address = 
+gce_service_account_pem_file_path = 
+gce_project_id = 
+

plugins/inventory/gce.py

+#!/usr/bin/python
+# Copyright 2013 Google Inc.
+#
+# 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/>.
+
+'''
+GCE external inventory script
+=================================
+
+Generates inventory that Ansible can understand by making API requests
+Google Compute Engine via the libcloud library.  Full install/configuration
+instructions for the gce* modules can be found in the comments of
+ansible/test/gce_tests.py.
+
+When run against a specific host, this script returns the following variables
+based on the data obtained from the libcloud Node object:
+ - gce_uuid
+ - gce_id
+ - gce_image
+ - gce_machine_type
+ - gce_private_ip
+ - gce_public_ip
+ - gce_name
+ - gce_description
+ - gce_status
+ - gce_zone
+ - gce_tags
+ - gce_metadata
+ - gce_network
+
+When run in --list mode, instances are grouped by the following categories:
+ - zone:
+   zone group name examples are us-central1-b, europe-west1-a, etc.
+ - instance tags:
+   An entry is created for each tag.  For example, if you have two instances
+   with a common tag called 'foo', they will both be grouped together under
+   the 'tag_foo' name.
+ - network name:
+   the name of the network is appended to 'network_' (e.g. the 'default'
+   network will result in a group named 'network_default')
+ - machine type
+   types follow a pattern like n1-standard-4, g1-small, etc.
+ - running status:
+   group name prefixed with 'status_' (e.g. status_running, status_stopped,..)
+ - image:
+   when using an ephemeral/scratch disk, this will be set to the image name
+   used when creating the instance (e.g. debian-7-wheezy-v20130816).  when
+   your instance was created with a root persistent disk it will be set to
+   'persistent_disk' since there is no current way to determine the image.
+
+Examples:
+  Execute uname on all instances in the us-central1-a zone
+  $ ansible -i gce.py us-central1-a -m shell -a "/bin/uname -a"
+
+  Use the GCE inventory script to print out instance specific information
+  $ plugins/inventory/gce.py --host my_instance
+
+Author: Eric Johnson <erjohnso@google.com>
+Version: 0.0.1
+'''
+
+import sys
+import os
+import argparse
+import ConfigParser
+
+try:
+    import json
+except ImportError:
+    import simplejson as json
+
+try:
+    from libcloud.compute.types import Provider
+    from libcloud.compute.providers import get_driver
+    _ = Provider.GCE
+except:
+    print("GCE inventory script requires libcloud >= 0.13")
+    sys.exit(1)
+
+
+class GceInventory(object):
+    def __init__(self):
+        # Read settings and parse CLI arguments
+        self.parse_cli_args()
+        self.driver = self.get_gce_driver()
+
+        # Just display data for specific host
+        if self.args.host:
+            print self.json_format_dict(self.node_to_dict(
+                    self.get_instance(self.args.host)))
+            sys.exit(0)
+
+        # Otherwise, assume user wants all instances grouped
+        print self.json_format_dict(self.group_instances())
+        sys.exit(0)
+
+
+    def get_gce_driver(self):
+        '''Determine GCE authorization settings and return libcloud driver.'''
+
+        config = ConfigParser.SafeConfigParser()
+        config.read(os.path.dirname(os.path.realpath(__file__)) + '/gce.ini')
+
+        # the GCE params in 'secrets.py' will override these
+        secrets_path = config.get('gce', 'libcloud_secrets')
+
+        secrets_found = False
+        try:
+            import secrets
+            args = getattr(secrets, 'GCE_PARAMS', ())
+            kwargs = getattr(secrets, 'GCE_KEYWORD_PARAMS', {})
+            secrets_found = True
+        except:
+            pass
+
+        if not secrets_found and secrets_path:
+            if not secrets_path.endswith('secrets.py'):
+                err = "Must specify libcloud secrets file as "
+                err += "/absolute/path/to/secrets.py"
+                print(err)
+                sys.exit(1)
+            sys.path.append(os.path.dirname(secrets_path))
+            try:
+                import secrets
+                args = getattr(secrets, 'GCE_PARAMS', ())
+                kwargs = getattr(secrets, 'GCE_KEYWORD_PARAMS', {})
+                secrets_found = True
+            except:
+                pass
+        if not secrets_found:
+            args = (
+                config.get('gce','gce_service_account_email_address'),
+                config.get('gce','gce_service_account_pem_file_path')
+            )
+            kwargs = {'project': config.get('gce','gce_project_id')}
+            
+        return get_driver(Provider.GCE)(*args, **kwargs)
+
+
+    def parse_cli_args(self):
+        ''' Command line argument processing '''
+
+        parser = argparse.ArgumentParser(
+                description='Produce an Ansible Inventory file based on GCE')
+        parser.add_argument('--list', action='store_true', default=True,
+                           help='List instances (default: True)')
+        parser.add_argument('--host', action='store',
+                           help='Get all information about an instance')
+        self.args = parser.parse_args()
+
+
+    def node_to_dict(self, inst):
+        md = {}
+        if inst.extra['metadata'].has_key('items'):
+            for entry in inst.extra['metadata']['items']:
+                md[entry['key']] = entry['value']
+
+        net = inst.extra['networkInterfaces'][0]['network'].split('/')[-1]
+        return {
+            'gce_uuid': inst.uuid,
+            'gce_id': inst.id,
+            'gce_image': inst.image,
+            'gce_machine_type': inst.size,
+            'gce_private_ip': inst.private_ip[0],
+            'gce_public_ip': inst.public_ip[0],
+            'gce_name': inst.name,
+            'gce_description': inst.extra['description'],
+            'gce_status': inst.extra['status'],
+            'gce_zone': inst.extra['zone'].name,
+            'gce_tags': inst.extra['tags'],
+            'gce_metadata': md,
+            'gce_network': net
+        }
+
+    def get_instance(self, instance_name):
+        '''Gets details about a specific instance '''
+        return self.driver.ex_get_node(instance_name)
+
+    def group_instances(self):
+        '''Group all instances'''
+        groups = {}
+        for node in self.driver.list_nodes():
+            name = node.name
+
+            zone = node.extra['zone'].name
+            if groups.has_key(zone): groups[zone].append(name)
+            else: groups[zone] = [name]
+
+            tags = node.extra['tags']
+            for t in tags:
+                tag = 'tag_%s' % t
+                if groups.has_key(tag): groups[tag].append(name)
+                else: groups[tag] = [name]
+
+            net = node.extra['networkInterfaces'][0]['network'].split('/')[-1]
+            net = 'network_%s' % net
+            if groups.has_key(net): groups[net].append(name)
+            else: groups[net] = [name]
+
+            machine_type = node.size
+            if groups.has_key(machine_type): groups[machine_type].append(name)
+            else: groups[machine_type] = [name]
+
+            image = node.image and node.image or 'persistent_disk'
+            if groups.has_key(image): groups[image].append(name)
+            else: groups[image] = [name]
+
+            status = node.extra['status']
+            stat = 'status_%s' % status.lower()
+            if groups.has_key(stat): groups[stat].append(name)
+            else: groups[stat] = [name]
+        return groups
+
+    def json_format_dict(self, data, pretty=False):
+        ''' Converts a dict to a JSON object and dumps it as a formatted
+        string '''
+
+        if pretty:
+            return json.dumps(data, sort_keys=True, indent=2)
+        else:
+            return json.dumps(data)
+
+
+# Run the script
+GceInventory()