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Ansible - Provisioning | provisioning-ansible |
Ansible Provisioner
Provisioner name: "ansible"
The ansible provisioner allows you to provision the guest using Ansible playbooks.
Ansible playbooks are YAML documents that comprise the set of steps to be orchestrated on one or more machines. This documentation page will not go into how to use Ansible or how to write Ansible playbooks, since Ansible is a complete deployment and configuration management system that is beyond the scope of a single page of documentation.
Warning: If you're not familiar with Ansible and Vagrant already, I recommend starting with the shell provisioner. However, if you're comfortable with Vagrant already, Vagrant is a great way to learn Ansible.
Inventory File
When using Ansible, it needs to know on which machines a given playbook should run. It does this by way of an inventory file which lists those machines. In the context of Vagrant, there are two ways to approach working with inventory files.
The first and simplest option is to not provide one to Vagrant at all. Vagrant will generate an
inventory file encompassing all of the virtual machine it manages, and use it for provisioning
machines. The generated inventory file is created adjacent to your Vagrantfile, named
vagrant_ansible_inventory
.
The ansible.groups
option can be used to pass a hash of group
names and group members to be included in the generated inventory file. Group variables
are intentionally not supported, as this practice is not recommended.
For example:
ansible.groups = {
"group1" => ["machine1"],
"group2" => ["machine2", "machine3"],
"all_groups:children" => ["group1", "group2", "group3"]
}
Note that unmanaged machines and undefined groups are not added to the inventory.
For example, group3
in the above example would not be added to the inventory file.
A generated inventory might look like:
# Generated by Vagrant
machine1 ansible_ssh_host=127.0.0.1 ansible_ssh_port=2200
machine2 ansible_ssh_host=127.0.0.1 ansible_ssh_port=2201
[group1]
machine1
[group2]
machine2
[all_groups:children]
group1
group2
The second option is for situations where you'd like to have more control over the inventory file.
If you provide the ansible.inventory_path
option referencing a specific inventory file dedicated
to your Vagrant project, that one will be used instead of generating it.
Such an inventory file for use with Vagrant might look like:
default ansible_ssh_host=192.168.111.222
Where the above IP address is one set in your Vagrantfile:
config.vm.network :private_network, ip: "192.168.111.222"
Note that machine names in Vagrantfile
and ansible.inventory_path
file should correspond,
unless you use ansible.limit
option to reference the correct machines.
Playbook
The second component of a successful Ansible provisioner setup is the Ansible playbook which contains the steps that should be run on the guest. Ansible's playbook documentation goes into great detail on how to author playbooks, and there are a number of best practices that can be applied to use Ansible's powerful features effectively. A playbook that installs and starts (or restarts if it was updated) the NTP daemon via YUM looks like:
---
- hosts: all
tasks:
- name: ensure ntpd is at the latest version
yum: pkg=ntp state=latest
notify:
- restart ntpd
handlers:
- name: restart ntpd
service: name=ntpd state=restarted
You can of course target other operating systems that don't have YUM by changing the playbook tasks. Ansible ships with a number of modules that make running otherwise tedious tasks dead simple.
Running Ansible
To run Ansible against your Vagrant guest, the basic Vagrantfile configuration looks like:
Vagrant.configure("2") do |config|
config.vm.provision "ansible" do |ansible|
ansible.playbook = "playbook.yml"
end
end
Since an Ansible playbook can include many files, you may also collect the related files in a directory structure like this:
$ tree
.
|-- Vagrantfile
|-- provisioning
| |-- group_vars
| |-- all
| |-- playbook.yml
In such an arrangement, the ansible.playbook
path should be adjusted accordingly:
Vagrant.configure("2") do |config|
config.vm.provision "ansible" do |ansible|
ansible.playbook = "provisioning/playbook.yml"
end
end
Vagrant will try to run the playbook.yml
playbook against all machines defined in your Vagrantfile.
Backward Compatibility Note:
Up to Vagrant 1.4, the Ansible provisioner could potentially connect (multiple times) to all hosts from the inventory file.
This behaviour is still possible by setting ansible.limit = 'all'
(see more details below).
Additional Options
The Ansible provisioner also includes a number of additional options that can be set,
all of which get passed to the ansible-playbook
command that ships with Ansible.
-
ansible.extra_vars
can be used to pass additional variables (with highest priority) to the playbook. This parameter can be a path to a JSON or YAML file, or a hash. For example:ansible.extra_vars = { ntp_server: "pool.ntp.org", nginx: { port: 8008, workers: 4 } }
These variables take the highest precedence over any other variables.
-
ansible.sudo
can be set totrue
to cause Ansible to perform commands using sudo. -
ansible.sudo_user
can be set to a string containing a username on the guest who should be used by the sudo command. -
ansible.ask_sudo_pass
can be set totrue
to require Ansible to prompt for a sudo password. -
ansible.limit
can be set to a string or an array of machines or groups from the inventory file to further control which hosts are affected. Note that:- As Vagrant 1.5, the machine name (taken from Vagrantfile) is set as default limit to ensure that
vagrant provision
steps only affect the expected machine. Settingansible.limit
will override this default. - Setting
ansible.limit = 'all'
can be used to make Ansible connects to all machines from the inventory file.
- As Vagrant 1.5, the machine name (taken from Vagrantfile) is set as default limit to ensure that
-
ansible.verbose
can be set to increase Ansible's verbosity to obtain detailed logging:'v'
, verbose mode'vv'
'vvv'
, more'vvvv'
, connection debugging
-
ansible.tags
can be set to a string or an array of tags. Only plays, roles and tasks tagged with these values will be executed. -
ansible.skip_tags
can be set to a string or an array of tags. Only plays, roles and tasks that do not match these values will be executed. -
ansible.start_at_task
can be set to a string corresponding to the task name where the playbook provision will start. -
ansible.raw_arguments
can be set to an array of strings corresponding to a list ofansible-playbook
arguments (e.g.['--check', '-M /my/modules']
). It is an unsafe wildcard that can be used to apply Ansible options that are not (yet) supported by this Vagrant provisioner. Following precedence rules apply:- Any supported options (described above) will override conflicting
raw_arguments
value (e.g.--tags
or--start-at-task
) - Vagrant default user authentication can be overridden via
raw_arguments
(with custom values for--user
and--private-key
)
- Any supported options (described above) will override conflicting
-
ansible.host_key_checking
can be set tofalse
which will disable host key checking and prevent"FAILED: (25, 'Inappropriate ioctl for device')"
errors from being reported during provisioner runs. The default value istrue
, which matches the default behavior of Ansible 1.2.1 and later.
Tips and Tricks
Ansible Parallel Execution
Vagrant is designed to provision multi-machine environments in sequence, but the following configuration pattern can be used to take advantage of Ansible parallelism:
config.vm.define 'machine2' do |machine|
machine.vm.hostname = 'machine2'
machine.vm.network "private_network", ip: "192.168.77.22"
end
config.vm.define 'machine1' do |machine|
machine.vm.hostname = 'machine1'
machine.vm.network "private_network", ip: "192.168.77.21"
machine.vm.provision :ansible do |ansible|
ansible.playbook = "playbook.yml"
# Disable default limit (required with Vagrant 1.5+)
ansible.limit = 'all'
end
end