Add ec2_elb_lb for managing ELBs

library/cloud/ec2_elb_lb

@@ -0,0 +1,448 @@
+#!/usr/bin/python
+# 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: ec2_elb_lb
+short_description: Creates or destroys Amazon ELB.
+  - Returns information about the load balancer.
+  - Will be marked changed when called only if state is changed.
+version_added: "1.4"
+requirements: [ "boto" ]
+author: Jim Dalton
+options:
+  state:
+    description:
+      - Create or destroy the ELB
+    required: true
+  name:
+    description:
+      - The name of the ELB
+    required: true
+  listeners:
+    description:
+      - List of ports/protocols for this ELB to listen on (see example)
+    required: false
+  purge_listeners:
+    description:
+      - Purge existing listeners on ELB that are not found in listeners
+    required: false
+    default: true
+  zones:
+    description:
+      - List of availability zones to enable on this ELB
+    required: false
+  purge_zones:
+    description:
+      - Purge existing availability zones on ELB that are not found in zones
+    required: false
+    default: False
+  aws_secret_key:
+    description:
+      - AWS secret key. If not set then the value of the AWS_SECRET_KEY environment variable is used. 
+    required: false
+    default: None
+    aliases: ['ec2_secret_key', 'secret_key']
+  aws_access_key:
+    description:
+      - AWS access key. If not set then the value of the AWS_ACCESS_KEY environment variable is used.
+    required: false
+    default: None
+    aliases: ['ec2_access_key', 'access_key']
+  region:
+    description:
+      - The AWS region to use. If not specified then the value of the EC2_REGION environment variable, if any, is used.
+    required: false
+    aliases: ['aws_region', 'ec2_region']
+
+"""
+
+EXAMPLES = """
+# Note: None of these examples set aws_access_key, aws_secret_key, or region.
+# It is assumed that their matching environment variables are set.
+
+# Basic provisioning example
+- local_action:
+    module: ec2_elb_lb
+    name: "test-please-delete"
+    state: present
+    zones:
+      - us-east-1a
+      - us-east-1d
+    listeners:
+      - protocol: http
+        load_balancer_port: 80
+        instance_port: 80
+      - protocol: https
+        load_balancer_port: 443
+        instance_protocol: http
+        instance_port: 80
+        ssl_certificate_id: "arn:aws:iam::123456789012:server-certificate/company/servercerts/ProdServerCert"
+
+# Ensure ELB is gone
+- local_action:
+    module: ec2_elb_lb
+    name: "test-please-delete"
+    state: absent
+
+# Normally, this module will purge any listeners that exist on the ELB
+# but aren't specified in the listeners parameter. If purge_listeners is
+# false it leaves them alone
+- local_action:
+    module: ec2_elb_lb
+    name: "test-please-delete"
+    state: present
+    zones:
+      - us-east-1a
+      - us-east-1d
+    listeners:
+      - protocol: http
+        load_balancer_port: 80
+        instance_port: 80
+    purge_listeners: no
+
+# Normally, this module will leave availability zones that are enabled
+# on the ELB alone. If purge_zones is true, then any extreneous zones
+# will be removed
+- local_action:
+    module: ec2_elb_lb
+    name: "test-please-delete"
+    state: present
+    zones:
+      - us-east-1a
+      - us-east-1d
+    listeners:
+      - protocol: http
+        load_balancer_port: 80
+        instance_port: 80
+    purge_zones: yes
+"""
+
+import sys
+import os
+
+AWS_REGIONS = ['ap-northeast-1',
+               'ap-southeast-1',
+               'ap-southeast-2',
+               'eu-west-1',
+               'sa-east-1',
+               'us-east-1',
+               'us-west-1',
+               'us-west-2']
+
+try:
+    import boto
+    import boto.ec2.elb
+    from boto.regioninfo import RegionInfo
+except ImportError:
+    print "failed=True msg='boto required for this module'"
+    sys.exit(1)
+
+
+class ElbManager(object):
+    """Handles ELB creation and destruction"""
+
+    def __init__(self, module, name, listeners=None, purge_listeners=None,
+                 zones=None, purge_zones=None, aws_access_key=None,
+                 aws_secret_key=None, region=None):
+        self.module = module
+        self.name = name
+        self.listeners = listeners
+        self.purge_listeners = purge_listeners
+        self.zones = zones
+        self.purge_zones = purge_zones
+
+        self.aws_access_key = aws_access_key
+        self.aws_secret_key = aws_secret_key
+        self.region = region
+
+        self.changed = False
+        self.status = 'gone'
+        self.elb_conn = self._get_elb_connection()
+        self.elb = self._get_elb()
+
+    def ensure_ok(self):
+        """Create the ELB"""
+        if not self.elb:
+            # Zones and listeners will be added at creation
+            self._create_elb()
+        else:
+            self._set_zones()
+            self._set_elb_listeners()
+
+    def ensure_gone(self):
+        """Destroy the ELB"""
+        if self.elb:
+            self._delete_elb()
+
+    def get_info(self):
+        if not self.elb:
+            info = {
+                'name': self.name,
+                'status': self.status
+            }
+        else:
+            info = {
+                'name': self.elb.name,
+                'dns_name': self.elb.dns_name,
+                'zones': self.elb.availability_zones,
+                'status': self.status
+            }
+            if self.elb.listeners:
+                info['listeners'] = [l.get_complex_tuple()
+                                     for l in self.elb.listeners]
+            elif self.status == 'created':
+                # When creating a new ELB, listeners don't show in the
+                # immediately returned result, so just include the
+                # ones that were added
+                info['listeners'] = [self._listener_as_tuple(l)
+                                     for l in self.listeners]
+            else:
+                info['listeners'] = []
+        return info
+
+    def _get_elb(self):
+        elbs = self.elb_conn.get_all_load_balancers()
+        for elb in elbs:
+            if self.name == elb.name:
+                self.status = 'ok'
+                return elb
+
+    def _get_elb_connection(self):
+        try:
+            endpoint = "elasticloadbalancing.%s.amazonaws.com" % self.region
+            connect_region = RegionInfo(name=self.region, endpoint=endpoint)
+            return boto.ec2.elb.ELBConnection(self.aws_access_key,
+                                              self.aws_secret_key,
+                                              region=connect_region)
+        except boto.exception.NoAuthHandlerFound, e:
+            self.module.fail_json(msg=str(e))
+
+    def _delete_elb(self):
+        # True if succeeds, exception raised if not
+        result = self.elb_conn.delete_load_balancer(name=self.name)
+        if result:
+            self.changed = True
+            self.status = 'deleted'
+
+    def _create_elb(self):
+        listeners = [self._listener_as_tuple(l) for l in self.listeners]
+        self.elb = self.elb_conn.create_load_balancer(name=self.name,
+                                                      zones=self.zones,
+                                                      complex_listeners=listeners)
+        if self.elb:
+            self.changed = True
+            self.status = 'created'
+
+    def _create_elb_listeners(self, listeners):
+        """Takes a list of listener tuples and creates them"""
+        # True if succeeds, exception raised if not
+        self.changed = self.elb_conn.create_load_balancer_listeners(self.name,
+                                                                    complex_listeners=listeners)
+
+    def _delete_elb_listeners(self, listeners):
+        """Takes a list of listener tuples and deletes them from the elb"""
+        ports = [l[0] for l in listeners]
+
+        # True if succeeds, exception raised if not
+        self.changed = self.elb_conn.delete_load_balancer_listeners(self.name,
+                                                                    ports)
+
+    def _set_elb_listeners(self):
+        """
+        Creates listeners specified by self.listeners; overwrites existing
+        listeners on these ports; removes extraneous listeners
+        """
+        listeners_to_add = []
+        listeners_to_remove = []
+        listeners_to_keep = []
+
+        # Check for any listeners we need to create or overwrite
+        for listener in self.listeners:
+            listener_as_tuple = self._listener_as_tuple(listener)
+
+            # First we loop through existing listeners to see if one is
+            # already specified for this port
+            existing_listener_found = None
+            for existing_listener in self.elb.listeners:
+                # Since ELB allows only one listener on each incoming port, a
+                # single match on the incomping port is all we're looking for
+                if existing_listener[0] == listener['load_balancer_port']:
+                    existing_listener_found = existing_listener.get_complex_tuple()
+                    break
+
+            if existing_listener_found:
+                # Does it match exactly?
+                if listener_as_tuple != existing_listener_found:
+                    # The ports are the same but something else is different,
+                    # so we'll remove the exsiting one and add the new one
+                    listeners_to_remove.append(existing_listener_found)
+                    listeners_to_add.append(listener_as_tuple)
+                else:
+                    # We already have this listener, so we're going to keep it
+                    listeners_to_keep.append(existing_listener_found)
+            else:
+                # We didn't find an existing listener, so just add the new one
+                listeners_to_add.append(listener_as_tuple)
+
+        # Check for any extraneous listeners we need to remove, if desired
+        if self.purge_listeners:
+            for existing_listener in self.elb.listeners:
+                existing_listener_tuple = existing_listener.get_complex_tuple()
+                if existing_listener_tuple in listeners_to_remove:
+                    # Already queued for removal
+                    continue
+                if existing_listener_tuple in listeners_to_keep:
+                    # Keep this one around
+                    continue
+                # Since we're not already removing it and we don't need to keep
+                # it, let's get rid of it
+                listeners_to_remove.append(existing_listener_tuple)
+
+        if listeners_to_remove:
+            self._delete_elb_listeners(listeners_to_remove)
+
+        if listeners_to_add:
+            self._create_elb_listeners(listeners_to_add)
+
+    def _listener_as_tuple(self, listener):
+        """Formats listener as a 4- or 5-tuples, in the order specified by the
+        ELB API"""
+        # N.B. string manipulations on protocols below (str(), upper()) is to
+        # ensure format matches output from ELB API
+        listener_list = [
+            listener['load_balancer_port'],
+            listener['instance_port'],
+            str(listener['protocol'].upper()),
+        ]
+
+        # Instance protocol is not required by ELB API; it defaults to match
+        # load balancer protocol. We'll mimic that behavior here
+        if 'instance_protocol' in listener:
+            listener_list.append(str(listener['instance_protocol'].upper()))
+        else:
+            listener_list.append(str(listener['protocol'].upper()))
+
+        if 'ssl_certificate_id' in listener:
+            listener_list.append(str(listener['ssl_certificate_id']))
+
+        return tuple(listener_list)
+
+    def _enable_zones(self, zones):
+        self.elb_conn.enable_availability_zones(self.name, zones)
+        self.changed = True
+
+    def _disable_zones(self, zones):
+        self.elb_conn.disable_availability_zones(self.name, zones)
+        self.changed = True
+
+    def _set_zones(self):
+        """Determine which zones need to be enabled or disabled on the ELB"""
+        if self.purge_zones:
+            zones_to_disable = list(set(self.elb.availability_zones) -
+                                    set(self.zones))
+            zones_to_enable = list(set(self.zones) -
+                                   set(self.elb.availability_zones))
+        else:
+            zones_to_disable = None
+            zones_to_enable = list(set(self.zones) -
+                                   set(self.elb.availability_zones))
+        if zones_to_enable:
+            self._enable_zones(zones_to_enable)
+        # N.B. This must come second, in case it would have removed all zones
+        if zones_to_disable:
+            self._disable_zones(zones_to_disable)
+
+
+def main():
+    module = AnsibleModule(
+        argument_spec=dict(
+            state={'required': True, 'choices': ['present', 'absent']},
+            name={'required': True},
+            listeners={'default': None, 'required': False, 'type': 'list'},
+            purge_listeners={'default': True, 'required': False,
+                             'choices': BOOLEANS, 'type': 'bool'},
+            zones={'default': None, 'required': False, 'type': 'list'},
+            purge_zones={'default': False, 'required': False,
+                         'choices': BOOLEANS, 'type': 'bool'},
+            aws_secret_key={'default': None,
+                            'aliases': ['ec2_secret_key', 'secret_key'],
+                            'no_log': True},
+            aws_access_key={'default': None,
+                            'aliases': ['ec2_access_key', 'access_key']},
+            region={'default': None, 'required': False,
+                    'aliases': ['aws_region', 'ec2_region'],
+                    'choices': AWS_REGIONS},
+        )
+    )
+
+    aws_secret_key = module.params['aws_secret_key']
+    aws_access_key = module.params['aws_access_key']
+    region = module.params['region']
+    name = module.params['name']
+    state = module.params['state']
+    listeners = module.params['listeners']
+    purge_listeners = module.params['purge_listeners']
+    zones = module.params['zones']
+    purge_zones = module.params['purge_zones']
+
+    if state == 'present' and not listeners:
+        module.fail_json(msg="At least one port is required for ELB creation")
+
+    if state == 'present' and not zones:
+        module.fail_json(msg="At least one availability zone is required for ELB creation")
+
+    if not aws_secret_key:
+        if 'AWS_SECRET_KEY' in os.environ:
+            aws_secret_key = os.environ['AWS_SECRET_KEY']
+        elif 'EC2_SECRET_KEY' in os.environ:
+            aws_secret_key = os.environ['EC2_SECRET_KEY']
+
+    if not aws_access_key:
+        if 'AWS_ACCESS_KEY' in os.environ:
+            aws_access_key = os.environ['AWS_ACCESS_KEY']
+        elif 'EC2_ACCESS_KEY' in os.environ:
+            aws_access_key = os.environ['EC2_ACCESS_KEY']
+
+    if not region:
+        if 'AWS_REGION' in os.environ:
+            region = os.environ['AWS_REGION']
+        elif 'EC2_REGION' in os.environ:
+            region = os.environ['EC2_REGION']
+
+    if not region:
+        module.fail_json(msg=str("Either region or EC2_REGION environment variable must be set."))
+
+    elb_man = ElbManager(module, name, listeners, purge_listeners, zones,
+                         purge_zones, aws_access_key, aws_secret_key,
+                         region=region)
+
+    if state == 'present':
+        elb_man.ensure_ok()
+    elif state == 'absent':
+        elb_man.ensure_gone()
+
+    ansible_facts = {'ec2_elb': 'info'}
+    ec2_facts_result = dict(changed=elb_man.changed,
+                            elb=elb_man.get_info(),
+                            ansible_facts=ansible_facts)
+
+    module.exit_json(**ec2_facts_result)
+
+# this is magic, see lib/ansible/module_common.py
+#<<INCLUDE_ANSIBLE_MODULE_COMMON>>
+
+main()