CloudStack Cloud Guide
======================
.. _cloudstack_introduction:
Introduction
````````````
The purpose of this section is to explain how to put Ansible modules together to use Ansible in a CloudStack context. You will find more usage examples in the details section of each module.
Ansible contains a number of extra modules for interacting with CloudStack based clouds. All modules support check mode and are designed to use idempotence and have been created, tested and are maintained by the community.
.. note:: Some of the modules will require domain admin or root admin privileges.
Prerequisites
`````````````
Prerequisites for using the CloudStack modules are minimal. In addition to ansible itself, all of the modules require the python library ``cs`` https://pypi.python.org/pypi/cs.
You'll need this Python module installed on the execution host, usually your workstation.
.. code-block:: bash
$ pip install cs
.. note:: cs also includes a command line interface for ad-hoc interaction with the CloudStack API e.g. ``$ cs listVirtualMachines state=Running``.
Credentials File
````````````````
You can pass credentials and the endpoint of your cloud as module arguments, however in most cases it is a far less work to store your credentials in the cloudstack.ini file.
The python library cs looks for the credentials file in the following order (last one wins):
* A ``.cloudstack.ini`` (note the dot) file in the home directory.
* A ``CLOUDSTACK_CONFIG`` environment variable pointing to an .ini file.
* A ``cloudstack.ini`` (without the dot) file in the current working directory, same directory as your playbooks are located.
The structure of the ini file must look like this:
.. code-block:: bash
$ cat $HOME/.cloudstack.ini
[cloudstack]
endpoint = https://cloud.example.com/client/api
key = api key
secret = api secret
.. Note:: The section ``[cloudstack]`` is the default section. ``CLOUDSTACK_REGION`` environment variable can be used to define the default section.
Regions
```````
If you use more than one CloudStack region, you can define as many sections as you want and name them as you like, e.g.:
.. code-block:: bash
$ cat $HOME/.cloudstack.ini
[exoscale]
endpoint = https://api.exoscale.ch/compute
key = api key
secret = api secret
[exmaple_cloud_one]
endpoint = https://cloud-one.example.com/client/api
key = api key
secret = api secret
[exmaple_cloud_two]
endpoint = https://cloud-two.example.com/client/api
key = api key
secret = api secret
.. Hint:: Sections can also be used to for login into the same region using different accounts.
By passing the argument ``api_region`` with the CloudStack modules, the region wanted will be selected.
.. code-block:: yaml
- name: ensure my ssh public key exists on Exoscale
local_action: cs_sshkeypair
name: my-ssh-key
public_key: "{{ lookup('file', '~/.ssh/id_rsa.pub') }}"
api_region: exoscale
Or by looping over a regions list if you want to do the task in every region:
.. code-block:: yaml
- name: ensure my ssh public key exists in all CloudStack regions
local_action: cs_sshkeypair
name: my-ssh-key
public_key: "{{ lookup('file', '~/.ssh/id_rsa.pub') }}"
api_region: "{{ item }}"
with_items:
- exoscale
- exmaple_cloud_one
- exmaple_cloud_two
Use Cases
`````````
The following should give you some ideas how to use the modules to provision VMs to the cloud. As always, there isn't only one way to do it. But as always: keep it simple for the beginning is always a good start.
Use Case: Provisioning in a Advanced Networking CloudStack setup
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Our CloudStack cloud has an advanced networking setup, we would like to provision web servers, which get a static NAT and open firewall ports 80 and 443. Further we provision database servers, to which we do not give any access to. For accessing the VMs by SSH we use a SSH jump host.
This is how our inventory looks like:
.. code-block:: ini
[cloud-vm:children]
webserver
db-server
jumphost
[webserver]
web-01.example.com public_ip=1.2.3.4
web-02.example.com public_ip=1.2.3.5
[db-server]
db-01.example.com
db-02.example.com
[jumphost]
jump.example.com public_ip=1.2.3.6
As you can see, the public IPs for our web servers and jumphost has been assigned as variable ``public_ip`` directly in the inventory.
The configure the jumphost, web servers and database servers, we use ``group_vars``. The ``group_vars`` directory contains 4 files for configuration of the groups: cloud-vm, jumphost, webserver and db-server. The cloud-vm is there for specifing the defaults of our cloud infrastructure.
.. code-block:: yaml
# file: group_vars/cloud-vm
---
cs_offering: Small
cs_firewall: []
Our database servers should get more CPU and RAM, so we define to use a ``Large`` offering for them.
.. code-block:: yaml
# file: group_vars/db-server
---
cs_offering: Large
The web servers should get a ``Small`` offering as we would scale them horizontally, which is also our default offering. We also ensure the known web ports are opened for the world.
.. code-block:: yaml
# file: group_vars/webserver
---
cs_firewall:
- { port: 80 }
- { port: 443 }
Further we provision a jump host which has only port 22 opened for accessing the VMs from our office IPv4 network.
.. code-block:: yaml
# file: group_vars/jumphost
---
cs_firewall:
- { port: 22, cidr: "17.17.17.0/24" }
Now to the fun part. We create a playbook to create our infrastructure we call it ``infra.yml``:
.. code-block:: yaml
# file: infra.yaml
---
- name: provision our VMs
hosts: cloud-vm
connection: local
tasks:
- name: ensure VMs are created and running
cs_instance:
name: "{{ inventory_hostname_short }}"
template: Linux Debian 7 64-bit 20GB Disk
service_offering: "{{ cs_offering }}"
state: running
- name: ensure firewall ports opened
cs_firewall:
ip_address: "{{ public_ip }}"
port: "{{ item.port }}"
cidr: "{{ item.cidr | default('0.0.0.0/0') }}"
with_items: cs_firewall
when: public_ip is defined
- name: ensure static NATs
cs_staticnat: vm="{{ inventory_hostname_short }}" ip_address="{{ public_ip }}"
when: public_ip is defined
In the above play we defined 3 tasks and use the group ``cloud-vm`` as target to handle all VMs in the cloud but instead SSH to these VMs, we use ``connetion=local`` to execute the API calls locally from our workstation.
In the first task, we ensure we have a running VM created with the Debian template. If the VM is already created but stopped, it would just start it. If you like to change the offering on an exisiting VM, you must add ``force: yes`` to the task, which would stop the VM, change the offering and start the VM again.
In the second task we ensure the ports are opened if we give a public IP to the VM.
In the third task we add static NAT to the VMs having a public IP defined.
.. Note:: The public IP addresses must have been acquired in advance, also see ``cs_ip_address``
.. Note:: For some modules, e.g. ``cs_sshkeypair`` you usually want this to be executed only once, not for every VM. Therefore you would make a separate play for it targeting localhost. You find an example in the use cases below.
Use Case: Provisioning on a Basic Networking CloudStack setup
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
A basic networking CloudStack setup is slightly different: Every VM gets a public IP directly assigned and security groups are used for access restriction policy.
This is how our inventory looks like:
.. code-block:: ini
[cloud-vm:children]
webserver
[webserver]
web-01.example.com
web-02.example.com
The default for your VMs looks like this:
.. code-block:: yaml
# file: group_vars/cloud-vm
---
cs_offering: Small
cs_securitygroups: [ 'default']
Our webserver will also be in security group ``web``:
.. code-block:: yaml
# file: group_vars/webserver
---
cs_securitygroups: [ 'default', 'web' ]
The playbook looks like the following:
.. code-block:: yaml
# file: infra.yaml
---
- name: cloud base setup
hosts: localhost
connection: local
tasks:
- name: upload ssh public key
cs_sshkeypair:
name: defaultkey
public_key: "{{ lookup('file', '~/.ssh/id_rsa.pub') }}"
- name: ensure security groups exist
cs_securitygroup:
name: "{{ item }}"
with_items:
- default
- web
- name: add inbound SSH to security group default
cs_securitygroup_rule:
security_group: default
start_port: "{{ item }}"
end_port: "{{ item }}"
with_items:
- 22
- name: add inbound TCP rules to security group web
cs_securitygroup_rule:
security_group: web
start_port: "{{ item }}"
end_port: "{{ item }}"
with_items:
- 80
- 443
- name: install VMs in the cloud
hosts: cloud-vm
connection: local
tasks:
- name: create and run VMs on CloudStack
cs_instance:
name: "{{ inventory_hostname_short }}"
template: Linux Debian 7 64-bit 20GB Disk
service_offering: "{{ cs_offering }}"
security_groups: "{{ cs_securitygroups }}"
ssh_key: defaultkey
state: Running
register: vm
- name: show VM IP
debug: msg="VM {{ inventory_hostname }} {{ vm.default_ip }}"
- name: assing IP to the inventory
set_fact: ansible_ssh_host={{ vm.default_ip }}
- name: waiting for SSH to come up
wait_for: port=22 host={{ vm.default_ip }} delay=5
In the first play we setup the security groups, in the second play the VMs will created be assigned to these groups. Further you see, that we assign the public IP returned from the modules to the host inventory. This is needed as we do not know the IPs we will get in advance. In a next step you would configure the DNS servers with these IPs for accassing the VMs with their DNS name.
In the last task we wait for SSH to be accessible, so any later play would be able to access the VM by SSH without failure.