Module for managing nodes in a Rackspace Cloud Load Balancer

library/cloud/rax_clb_nodes

+#!/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: rax_clb_nodes
+short_description: add, modify and remove nodes from a Rackspace Cloud Load Balancer
+description:
+  - Adds, modifies and removes nodes from a Rackspace Cloud Load Balancer
+version_added: "1.3"
+options:
+  address:
+    required: false
+    description:
+      - IP address or domain name of the node
+  api_key:
+    required: false
+    description:
+      - Rackspace API key (overrides C(credentials))
+  condition:
+    required: false
+    choices: [ "enabled", "disabled", "draining" ]
+    description:
+      - Condition for the node, which determines its role within the load
+        balancer
+  credentials:
+    required: false
+    description:
+      - File to find the Rackspace credentials in (ignored if C(api_key) and
+        C(username) are provided)
+  load_balancer_id:
+    required: true
+    type: integer
+    description:
+      - Load balancer id
+  node_id:
+    required: false
+    type: integer
+    description:
+      - Node id
+  port:
+    required: false
+    type: integer
+    description:
+      - Port number of the load balanced service on the node
+  region:
+    required: false
+    description:
+     - Region to authenticate in
+  state:
+    required: false
+    default: "present"
+    choices: [ "present", "absent" ]
+    description:
+      - Indicate desired state of the node
+  type:
+    required: false
+    choices: [ "primary", "secondary" ]
+    description:
+      - Type of node
+  username:
+    required: false
+    description:
+     - Rackspace username (overrides C(credentials))
+  virtualenv:
+    required: false
+    description:
+      - Path to a virtualenv that should be activated before doing anything.
+        The virtualenv has to already exist. Useful if installing pyrax
+        globally is not an option.
+  wait:
+    required: false
+    default: "no"
+    choices: [ "yes", "no" ]
+    description:
+      - Wait for the load balancer to become active before returning
+  wait_timeout:
+    required: false
+    type: integer
+    default: 30
+    description:
+      - How long to wait before giving up and returning an error
+  weight:
+    required: false
+    description:
+      - Weight of node
+requirements: [ "pyrax" ]
+author: Lukasz Kawczynski
+notes:
+  - The following environment variables can be used: C(RAX_USERNAME),
+    C(RAX_API_KEY), C(RAX_CREDENTIALS) and C(RAX_REGION).
+'''
+
+EXAMPLES = '''
+# Add a new node to the load balancer
+- local_action:
+    module: rax_clb_nodes
+    load_balancer_id: 71
+    address: 10.2.2.3
+    port: 80
+    condition: enabled
+    type: primary
+    wait: yes
+    credentials: /path/to/credentials
+
+# Drain connections from a node
+- local_action:
+    module: rax_clb_nodes
+    load_balancer_id: 71
+    node_id: 410
+    condition: draining
+    wait: yes
+    credentials: /path/to/credentials
+
+# Remove a node from the load balancer
+- local_action:
+    module: rax_clb_nodes
+    load_balancer_id: 71
+    node_id: 410
+    state: absent
+    wait: yes
+    credentials: /path/to/credentials
+'''
+
+import os
+
+
+def _activate_virtualenv(path):
+    path = os.path.expanduser(path)
+    activate_this = os.path.join(path, 'bin', 'activate_this.py')
+    execfile(activate_this, dict(__file__=activate_this))
+
+
+def _get_node(lb, node_id):
+    """Return a node with the given `node_id`"""
+    for node in lb.nodes:
+        if node.id == node_id:
+            return node
+    return None
+
+
+def _is_primary(node):
+    """Return True if node is primary and enabled"""
+    return (node.type.lower() == 'primary' and
+            node.condition.lower() == 'enabled')
+
+
+def _get_primary_nodes(lb):
+    """Return a list of primary and enabled nodes"""
+    nodes = []
+    for node in lb.nodes:
+        if _is_primary(node):
+            nodes.append(node)
+    return nodes
+
+
+def _node_to_dict(node):
+    """Return a dictionary containing node details"""
+    if not node:
+        return {}
+    return {
+        'address': node.address,
+        'condition': node.condition,
+        'id': node.id,
+        'port': node.port,
+        'type': node.type,
+        'weight': node.weight,
+    }
+
+
+def main():
+    module = AnsibleModule(
+        argument_spec=dict(
+            address=dict(),
+            api_key=dict(),
+            condition=dict(choices=['enabled', 'disabled', 'draining']),
+            credentials=dict(),
+            load_balancer_id=dict(required=True, type='int'),
+            node_id=dict(type='int'),
+            port=dict(type='int'),
+            region=dict(),
+            state=dict(default='present', choices=['present', 'absent']),
+            type=dict(choices=['primary', 'secondary']),
+            username=dict(),
+            virtualenv=dict(),
+            wait=dict(default=False, choices=BOOLEANS, type='bool'),
+            wait_timeout=dict(default=30, type='int'),
+            weight=dict(type='int'),
+        ),
+        required_together=[
+            ['api_key', 'username']
+        ],
+    )
+
+    address = module.params['address']
+    api_key = module.params['api_key']
+    condition = (module.params['condition'] and
+                 module.params['condition'].upper())
+    credentials = module.params['credentials']
+    load_balancer_id = module.params['load_balancer_id']
+    node_id = module.params['node_id']
+    port = module.params['port']
+    region = module.params['region']
+    state = module.params['state']
+    typ = module.params['type'] and module.params['type'].upper()
+    username = module.params['username']
+    virtualenv = module.params['virtualenv']
+    wait = module.params['wait']
+    wait_timeout = module.params['wait_timeout'] or 1
+    weight = module.params['weight']
+
+    if virtualenv:
+        try:
+            _activate_virtualenv(virtualenv)
+        except IOError, e:
+            module.fail_json(msg='Failed to activate virtualenv %s (%s)' % (
+                                 virtualenv, e))
+
+    try:
+        import pyrax
+    except ImportError:
+        module.fail_json(msg='pyrax is not installed')
+
+    username = username or os.environ.get('RAX_USERNAME')
+    api_key = api_key or os.environ.get('RAX_API_KEY')
+    credentials = credentials or os.environ.get('RAX_CREDENTIALS')
+    region = region or os.environ.get('RAX_REGION')
+
+    pyrax.set_setting("identity_type", "rackspace")
+
+    try:
+        if api_key and username:
+            pyrax.set_credentials(username, api_key=api_key, region=region)
+        elif credentials:
+            credentials = os.path.expanduser(credentials)
+            pyrax.set_credential_file(credentials, region=region)
+        else:
+            module.fail_json(msg='Credentials not set')
+    except pyrax.exc.PyraxException, e:
+        module.fail_json(msg='%s' % e.message)
+
+    if not pyrax.cloud_loadbalancers:
+        module.fail_json(msg='Failed to instantiate load balancer client '
+                             '(possibly incorrect region)')
+
+    try:
+        lb = pyrax.cloud_loadbalancers.get(load_balancer_id)
+    except pyrax.exc.PyraxException, e:
+        module.fail_json(msg='%s' % e.message)
+
+    if node_id:
+        node = _get_node(lb, node_id)
+    else:
+        node = None
+
+    result = _node_to_dict(node)
+
+    if state == 'absent':
+        if not node:  # Removing a non-existent node
+            module.exit_json(changed=False, state=state)
+
+        # The API detects this as well but currently pyrax does not return a
+        # meaningful error message
+        if _is_primary(node) and len(_get_primary_nodes(lb)) == 1:
+            module.fail_json(
+                msg='At least one primary node has to be enabled')
+
+        try:
+            lb.delete_node(node)
+            result = {}
+        except pyrax.exc.NotFound:
+            module.exit_json(changed=False, state=state)
+        except pyrax.exc.PyraxException, e:
+            module.fail_json(msg='%s' % e.message)
+    else:  # present
+        if not node:
+            if node_id:  # Updating a non-existent node
+                msg = 'Node %d not found' % node_id
+                if lb.nodes:
+                    msg += (' (available nodes: %s)' %
+                            ', '.join([str(x.id) for x in lb.nodes]))
+                module.fail_json(msg=msg)
+            else:  # Creating a new node
+                try:
+                    node = pyrax.cloudloadbalancers.Node(
+                        address=address, port=port, condition=condition,
+                        weight=weight, type=typ)
+                    resp, body = lb.add_nodes([node])
+                    result.update(body['nodes'][0])
+                except pyrax.exc.PyraxException, e:
+                    module.fail_json(msg='%s' % e.message)
+        else:  # Updating an existing node
+            immutable = {
+                'address': address,
+                'port': port,
+            }
+
+            mutable = {
+                'condition': condition,
+                'type': typ,
+                'weight': weight,
+            }
+
+            for name, value in immutable.items():
+                if value:
+                    module.fail_json(
+                        msg='Attribute %s cannot be modified' % name)
+
+            for name, value in mutable.items():
+                if value is None or value == getattr(node, name):
+                    mutable.pop(name)
+
+            if not mutable:
+                module.exit_json(changed=False, state=state, node=result)
+
+            try:
+                # The diff has to be set explicitly to update node's weight and
+                # type; this should probably be fixed in pyrax
+                lb.update_node(node, diff=mutable)
+                result.update(mutable)
+            except pyrax.exc.PyraxException, e:
+                module.fail_json(msg='%s' % e.message)
+
+    if wait:
+        pyrax.utils.wait_until(lb, "status", "ACTIVE", interval=1,
+                               attempts=wait_timeout)
+        if lb.status != 'ACTIVE':
+            module.fail_json(
+                msg='Load balancer not active after %ds (current status: %s)' %
+                    (wait_timeout, lb.status.lower()))
+
+    kwargs = {'node': result} if result else {}
+    module.exit_json(changed=True, state=state, **kwargs)
+
+# this is magic, see lib/ansible/module_common.py
+#<<INCLUDE_ANSIBLE_MODULE_COMMON>>
+main()