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ansible/docsite/rst/guide_rax.rst
Laurens Van Houtven 62f3c10302 Tell user to make inventory plugin executable 
The current version mentions nothing about chmod +x'ing the rax.py file, which means you get a really weird error message when you try to follow it:

```
raise ValueError, "No closing quotation"
```

... from deep inside shlex.py. I'm sure that makes sense if you realized that meant that it was trying to parse `rax.py` as an ini file...
2014-02-05 19:45:08 +01:00

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Rackspace Cloud Guide
=====================
.. _introduction:
Introduction
````````````
.. note:: This section of the documentation is under construction. We are in the process of adding more examples about the Rackspace modules and how they work together. Once complete, there will also be examples for Rackspace Cloud in `ansible-examples <http://github.com/ansible/ansible-examples/>`_.
Ansible contains a number of core modules for interacting with Rackspace Cloud.
The purpose of this section is to explain how to put Ansible modules together
(and use inventory scripts) to use Ansible in Rackspace Cloud context.
Prerequisites for using the rax modules are minimal. In addition to ansible itself,
all of the modules require and are tested against pyrax 1.5 or higher.
You'll need this Python module installed on the execution host.
pyrax is not currently available in many operating system
package repositories, so you will likely need to install it via pip:
.. code-block:: bash
$ pip install pyrax
The following steps will often execute from the control machine against the Rackspace Cloud API, so it makes sense
to add localhost to the inventory file. (Ansible may not require this manual step in the future):
.. code-block:: ini
[localhost]
localhost ansible_connection=local
In playbook steps we'll typically be using the following pattern:
.. code-block:: yaml
- hosts: localhost
connection: local
gather_facts: False
tasks:
.. _credentials_file:
Credentials File
````````````````
The `rax.py` inventory script and all `rax` modules support a standard `pyrax` credentials file that looks like:
.. code-block:: ini
[rackspace_cloud]
username = myraxusername
api_key = d41d8cd98f00b204e9800998ecf8427e
Setting the environment parameter RAX_CREDS_FILE to the path of this file will help Ansible find how to load
this information.
More information about this credentials file can be found at
https://github.com/rackspace/pyrax/blob/master/docs/getting_started.md#authenticating
.. _virtual_environment:
Running from a Python Virtual Environment (Optional)
++++++++++++++++++++++++++++++++++++++++++++++++++++
Special considerations need to
be taken if pyrax is not installed globally but instead using a python virtualenv (it's fine if you install it globally).
Ansible assumes, unless otherwise instructed, that the python binary will live at
/usr/bin/python. This is done so via the interpret line in the modules, however
when instructed using ansible_python_interpreter, ansible will use this specified path instead for finding
python.
If using virtualenv, you may wish to modify your localhost inventory definition to find this location as follows:
.. code-block:: ini
[localhost]
localhost ansible_connection=local ansible_python_interpreter=/path/to/ansible_venv/bin/python
.. _provisioning:
Provisioning
````````````
Now for the fun parts.
The 'rax' module provides the ability to provision instances within Rackspace Cloud. Typically the
provisioning task will be performed from your Ansible control server against the Rackspace cloud API.
.. note::
Authentication with the Rackspace-related modules is handled by either
specifying your username and API key as environment variables or passing
them as module arguments.
Here is a basic example of provisioning a instance in ad-hoc mode:
.. code-block:: bash
$ ansible localhost -m rax -a "name=awx flavor=4 image=ubuntu-1204-lts-precise-pangolin wait=yes" -c local
Here's what it would look like in a playbook, assuming the parameters were defined in variables:
.. code-block:: yaml
tasks:
- name: Provision a set of instances
local_action:
module: rax
name: "{{ rax_name }}"
flavor: "{{ rax_flavor }}"
image: "{{ rax_image }}"
count: "{{ rax_count }}"
group: "{{ group }}"
wait: yes
register: rax
By registering the return value of the step, it is then possible to dynamically add the resulting hosts to inventory (temporarily, in memory).
This facilitates performing configuration actions on the hosts immediately in a subsequent task::
- name: Add the instances we created (by public IP) to the group 'raxhosts'
local_action:
module: add_host
hostname: "{{ item.name }}"
ansible_ssh_host: "{{ item.rax_accessipv4 }}"
ansible_ssh_pass: "{{ item.rax_adminpass }}"
groupname: raxhosts
with_items: rax.success
when: rax.action == 'create'
With the host group now created, a second play in your provision playbook could now configure them, for example::
- name: Configuration play
hosts: raxhosts
user: root
roles:
- ntp
- webserver
The method above ties the configuration of a host with the provisioning step. This isn't always what you want, and leads us
to the next section.
.. _host_inventory:
Host Inventory
``````````````
Once your nodes are spun up, you'll probably want to talk to them again.
The best way to handle his is to use the rax inventory plugin, which dynamically queries Rackspace Cloud and tells Ansible what
nodes you have to manage.
You might want to use this even if you are spinning up Ansible via other tools, including the Rackspace Cloud user interface.
The inventory plugin can be used to group resources by their meta data. Utilizing meta data is highly
recommended in rax and can provide an easy way to sort between host groups and roles.
If you don't want to use the ``rax.py`` dynamic inventory script, you could also still choose to manually manage your INI inventroy file,
though this is less recommended.
In Ansible it is quite possible to use multiple dynamic inventory plugins along with INI file data. Just put them in a common
directory and be sure the scripts are chmod +x, and the INI-based ones are not.
.. _raxpy:
rax.py
++++++
To use the rackspace dynamic inventory script, copy ``rax.py`` from ``plugins/inventory`` into your inventory directory and make it executable. You can specify credentials for ``rax.py`` utilizing the ``RAX_CREDS_FILE`` environment variable.
.. note:: Users of :doc:`tower` will note that dynamic inventory is natively supported by Tower, and all you have to do is associate a group with your Rackspace Cloud credentials, and it will easily synchronize without going through these steps::
$ RAX_CREDS_FILE=~/.raxpub ansible all -i rax.py -m setup
``rax.py`` also accepts a ``RAX_REGION`` environment variable, which can contain an individual region, or a
comma separated list of regions.
When using ``rax.py``, you will not have a 'localhost' defined in the inventory.
As mentioned previously, you will often be running most of these modules outside of the host loop,
and will need 'localhost' defined. The recommended way to do this, would be to create an ``inventory`` directory,
and place both the ``rax.py`` script and a file containing ``localhost`` in it.
Executing ``ansible`` or ``ansible-playbook`` and specifying the ``inventory`` directory instead
of an individual file, will cause ansible to evaluate each file in that directory for inventory.
Let's test our inventory script to see if it can talk to Rackspace Cloud.
.. code-block:: bash
$ RAX_CREDS_FILE=~/.raxpub ansible all -i inventory/ -m setup
Assuming things are properly configured, the ``rax.py`` inventory script will output information similar to the
following information, which will be utilized for inventory and variables.
.. code-block:: json
{
"ORD": [
"test"
],
"_meta": {
"hostvars": {
"test": {
"ansible_ssh_host": "1.1.1.1",
"rax_accessipv4": "1.1.1.1",
"rax_accessipv6": "2607:f0d0:1002:51::4",
"rax_addresses": {
"private": [
{
"addr": "2.2.2.2",
"version": 4
}
],
"public": [
{
"addr": "1.1.1.1",
"version": 4
},
{
"addr": "2607:f0d0:1002:51::4",
"version": 6
}
]
},
"rax_config_drive": "",
"rax_created": "2013-11-14T20:48:22Z",
"rax_flavor": {
"id": "performance1-1",
"links": [
{
"href": "https://ord.servers.api.rackspacecloud.com/111111/flavors/performance1-1",
"rel": "bookmark"
}
]
},
"rax_hostid": "e7b6961a9bd943ee82b13816426f1563bfda6846aad84d52af45a4904660cde0",
"rax_human_id": "test",
"rax_id": "099a447b-a644-471f-87b9-a7f580eb0c2a",
"rax_image": {
"id": "b211c7bf-b5b4-4ede-a8de-a4368750c653",
"links": [
{
"href": "https://ord.servers.api.rackspacecloud.com/111111/images/b211c7bf-b5b4-4ede-a8de-a4368750c653",
"rel": "bookmark"
}
]
},
"rax_key_name": null,
"rax_links": [
{
"href": "https://ord.servers.api.rackspacecloud.com/v2/111111/servers/099a447b-a644-471f-87b9-a7f580eb0c2a",
"rel": "self"
},
{
"href": "https://ord.servers.api.rackspacecloud.com/111111/servers/099a447b-a644-471f-87b9-a7f580eb0c2a",
"rel": "bookmark"
}
],
"rax_metadata": {
"foo": "bar"
},
"rax_name": "test",
"rax_name_attr": "name",
"rax_networks": {
"private": [
"2.2.2.2"
],
"public": [
"1.1.1.1",
"2607:f0d0:1002:51::4"
]
},
"rax_os-dcf_diskconfig": "AUTO",
"rax_os-ext-sts_power_state": 1,
"rax_os-ext-sts_task_state": null,
"rax_os-ext-sts_vm_state": "active",
"rax_progress": 100,
"rax_status": "ACTIVE",
"rax_tenant_id": "111111",
"rax_updated": "2013-11-14T20:49:27Z",
"rax_user_id": "22222"
}
}
}
}
.. _standard_inventory:
Standard Inventory
++++++++++++++++++
When utilizing a standard ini formatted inventory file (as opposed to the inventory plugin),
it may still be adventageous to retrieve discoverable hostvar information from the Rackspace API.
This can be achieved with the ``rax_facts`` module and an inventory file similar to the following:
.. code-block:: ini
[test_servers]
hostname1 rax_region=ORD
hostname2 rax_region=ORD
.. code-block:: yaml
- name: Gather info about servers
hosts: test_servers
gather_facts: False
tasks:
- name: Get facts about servers
local_action:
module: rax_facts
credentials: ~/.raxpub
name: "{{ inventory_hostname }}"
region: "{{ rax_region }}"
- name: Map some facts
set_fact:
ansible_ssh_host: "{{ rax_accessipv4 }}"
While you don't need to know how it works, it may be interesting to know what kind of variables are returned.
The ``rax_facts`` module provides facts as followings, which match the ``rax.py`` inventory script:
.. code-block:: json
{
"ansible_facts": {
"rax_accessipv4": "1.1.1.1",
"rax_accessipv6": "2607:f0d0:1002:51::4",
"rax_addresses": {
"private": [
{
"addr": "2.2.2.2",
"version": 4
}
],
"public": [
{
"addr": "1.1.1.1",
"version": 4
},
{
"addr": "2607:f0d0:1002:51::4",
"version": 6
}
]
},
"rax_config_drive": "",
"rax_created": "2013-11-14T20:48:22Z",
"rax_flavor": {
"id": "performance1-1",
"links": [
{
"href": "https://ord.servers.api.rackspacecloud.com/111111/flavors/performance1-1",
"rel": "bookmark"
}
]
},
"rax_hostid": "e7b6961a9bd943ee82b13816426f1563bfda6846aad84d52af45a4904660cde0",
"rax_human_id": "test",
"rax_id": "099a447b-a644-471f-87b9-a7f580eb0c2a",
"rax_image": {
"id": "b211c7bf-b5b4-4ede-a8de-a4368750c653",
"links": [
{
"href": "https://ord.servers.api.rackspacecloud.com/111111/images/b211c7bf-b5b4-4ede-a8de-a4368750c653",
"rel": "bookmark"
}
]
},
"rax_key_name": null,
"rax_links": [
{
"href": "https://ord.servers.api.rackspacecloud.com/v2/111111/servers/099a447b-a644-471f-87b9-a7f580eb0c2a",
"rel": "self"
},
{
"href": "https://ord.servers.api.rackspacecloud.com/111111/servers/099a447b-a644-471f-87b9-a7f580eb0c2a",
"rel": "bookmark"
}
],
"rax_metadata": {
"foo": "bar"
},
"rax_name": "test",
"rax_name_attr": "name",
"rax_networks": {
"private": [
"2.2.2.2"
],
"public": [
"1.1.1.1",
"2607:f0d0:1002:51::4"
]
},
"rax_os-dcf_diskconfig": "AUTO",
"rax_os-ext-sts_power_state": 1,
"rax_os-ext-sts_task_state": null,
"rax_os-ext-sts_vm_state": "active",
"rax_progress": 100,
"rax_status": "ACTIVE",
"rax_tenant_id": "111111",
"rax_updated": "2013-11-14T20:49:27Z",
"rax_user_id": "22222"
},
"changed": false
}
Use Cases
`````````
This section covers some additional usage examples built around a specific use case.
.. _example_1:
Example 1
+++++++++
Create an isolated cloud network and build a server
.. code-block:: yaml
- name: Build Servers on an Isolated Network
hosts: localhost
connection: local
gather_facts: False
tasks:
- name: Network create request
local_action:
module: rax_network
credentials: ~/.raxpub
label: my-net
cidr: 192.168.3.0/24
region: IAD
state: present
- name: Server create request
local_action:
module: rax
credentials: ~/.raxpub
name: web%04d.example.org
flavor: 2
image: ubuntu-1204-lts-precise-pangolin
disk_config: manual
networks:
- public
- my-net
region: IAD
state: present
count: 5
exact_count: yes
group: web
wait: yes
wait_timeout: 360
register: rax
.. _example_2:
Example 2
+++++++++
Build a complete webserver environment with servers, custom networks and load balancers, install nginx and create a custom index.html
.. code-block:: yaml
---
- name: Build environment
hosts: localhost
connection: local
gather_facts: False
tasks:
- name: Load Balancer create request
local_action:
module: rax_clb
credentials: ~/.raxpub
name: my-lb
port: 80
protocol: HTTP
algorithm: ROUND_ROBIN
type: PUBLIC
timeout: 30
region: IAD
wait: yes
state: present
meta:
app: my-cool-app
register: clb
- name: Network create request
local_action:
module: rax_network
credentials: ~/.raxpub
label: my-net
cidr: 192.168.3.0/24
state: present
region: IAD
register: network
- name: Server create request
local_action:
module: rax
credentials: ~/.raxpub
name: web%04d.example.org
flavor: performance1-1
image: ubuntu-1204-lts-precise-pangolin
disk_config: manual
networks:
- public
- private
- my-net
region: IAD
state: present
count: 5
exact_count: yes
group: web
wait: yes
register: rax
- name: Add servers to web host group
local_action:
module: add_host
hostname: "{{ item.name }}"
ansible_ssh_host: "{{ item.rax_accessipv4 }}"
ansible_ssh_pass: "{{ item.rax_adminpass }}"
ansible_ssh_user: root
groupname: web
with_items: rax.success
when: rax.action == 'create'
- name: Add servers to Load balancer
local_action:
module: rax_clb_nodes
credentials: ~/.raxpub
load_balancer_id: "{{ clb.balancer.id }}"
address: "{{ item.rax_networks.private|first }}"
port: 80
condition: enabled
type: primary
wait: yes
region: IAD
with_items: rax.success
when: rax.action == 'create'
- name: Configure servers
hosts: web
handlers:
- name: restart nginx
service: name=nginx state=restarted
tasks:
- name: Install nginx
apt: pkg=nginx state=latest update_cache=yes cache_valid_time=86400
notify:
- restart nginx
- name: Ensure nginx starts on boot
service: name=nginx state=started enabled=yes
- name: Create custom index.html
copy: content="{{ inventory_hostname }}" dest=/usr/share/nginx/www/index.html
owner=root group=root mode=0644
.. _advanced_usage:
Advanced Usage
``````````````
.. _awx_autoscale:
Autoscaling with Tower
++++++++++++++++++++++
:doc:`tower` also contains a very nice feature for auto-scaling use cases.
In this mode, a simple curl script can call a defined URL and the server will "dial out" to the requester
and configure an instance that is spinning up. This can be a great way to reconfigure ephmeral nodes.
See the Tower documentation for more details.
A benefit of using the callback in Tower over pull mode is that job results are still centrally recorded
and less information has to be shared with remote hosts.
.. _pending_information:
Pending Information
```````````````````
More to come!
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