vagrant/website/source/docs/provisioning/ansible_intro.html.md

259 lines
11 KiB
Markdown
Raw Normal View History

---
layout: "docs"
page_title: "Ansible - Short Introduction"
sidebar_current: "provisioning-ansible-intro"
description: |-
This page includes options and information that is applicable to both Vagrant
Ansible provisioners.
---
# Ansible and Vagrant
The information below is applicable to both Vagrant Ansible provisioners:
- [`ansible`](/docs/provisioning/ansible.html), where Ansible is executed on the **Vagrant host**
- [`ansible_local`](/docs/provisioning/ansible_local.html), where Ansible is executed on the **Vagrant guest**
The list of common options for these two provisioners is documented in a [separate documentation page](/docs/provisioning/ansible_common.html).
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 Vagrant documentation.
To learn more about Ansible, please consult the [Ansible Documentation Site](https://docs.ansible.com/).
## The Playbook File
The first 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](https://docs.ansible.com/playbooks.html) goes into great detail on how to author playbooks, and there are a number of [best practices](https://docs.ansible.com/playbooks_best_practices.html) that can be applied to use Ansible's powerful features effectively.
A playbook that installs and starts (or restarts) 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 do not have YUM by changing the playbook tasks. Ansible ships with a number of [modules](https://docs.ansible.com/modules.html) that make running otherwise tedious tasks dead simple.
### Running Ansible
The `playbook` option is strictly required by both Ansible provisioners ([`ansible`](/docs/provisioning/ansible.html) and [`ansible_local`](/docs/provisioning/ansible_local.html)), as illustrated in this basic Vagrantfile` configuration:
```ruby
Vagrant.configure("2") do |config|
# Use :ansible or :ansible_local to
# select the provisioner of your choice
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](https://docs.ansible.com/playbooks_best_practices.html#directory-layout) like this:
```
.
|-- Vagrantfile
|-- provisioning
| |-- group_vars
| |-- all
| |-- roles
| |-- bar
| |-- foo
| |-- playbook.yml
```
In such an arrangement, the `ansible.playbook` path should be adjusted accordingly:
```ruby
Vagrant.configure("2") do |config|
config.vm.provision "ansible" do |ansible|
ansible.playbook = "provisioning/playbook.yml"
end
end
```
## The 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](https://docs.ansible.com/intro_inventory.html) file which lists those machines. In the context of Vagrant, there are two ways to approach working with inventory files.
### Auto-Generated Inventory
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 machines it manages, and use it for provisioning machines.
#### Example with the [`ansible`](/docs/provisioning/ansible.html) provisioner
```
# Generated by Vagrant
default ansible_ssh_host=127.0.0.1 ansible_ssh_port=2200 ansible_ssh_user='vagrant' ansible_ssh_private_key_file='/home/.../.vagrant/machines/default/virtualbox/private_key'
```
Note that the generated inventory file is stored as part of your local Vagrant environment in
`.vagrant/provisioners/ansible/inventory/vagrant_ansible_inventory`.
#### Example with the [`ansible_local`](/docs/provisioning/ansible_local.html) provisioner
```
# Generated by Vagrant
default ansible_connection=local
```
Note that the generated inventory file is uploaded to the guest VM in a subdirectory of [`tmp_path`](/docs/provisioning/ansible_local.html), e.g. `/tmp/vagrant-ansible/inventory/vagrant_ansible_local_inventory`.
#### Host Variables
2015-12-01 15:43:03 +00:00
As of Vagrant 1.8.0, the [`host_vars`](/docs/provisioning/ansible_common.html#host_vars) option can be used to set [variables for individual hosts](https://docs.ansible.com/ansible/intro_inventory.html#host-variables) in the generated inventory file (see also the notes on group variables below).
2015-12-01 15:43:03 +00:00
With this configuration example:
2015-12-01 15:43:03 +00:00
```
Vagrant.configure("2") do |config|
2015-12-01 15:43:03 +00:00
config.vm.define "host1"
config.vm.define "host2"
config.vm.provision "ansible" do |ansible|
ansible.playbook = "playbook.yml"
ansible.host_vars = {
"host1" => {"http_port" => 80,
"maxRequestsPerChild" => 808},
"host2" => {"http_port" => 303,
"maxRequestsPerChild" => 909}
}
end
end
```
Vagrant would generate the following inventory file:
2015-12-01 15:43:03 +00:00
```
# Generated by Vagrant
host1 ansible_ssh_host=... http_port=80 maxRequestsPerChild=808
host2 ansible_ssh_host=... http_port=303 maxRequestsPerChild=909
2015-12-01 15:43:03 +00:00
```
#### Groups and Group Variables
The [`groups`](/docs/provisioning/ansible_common.html#groups) option can be used to pass a hash of group names and group members to be included in the generated inventory file.
As of Vagrant 1.8.0, it is also possible to specify [group variables](https://docs.ansible.com/ansible/intro_inventory.html#group-variables), and group members as [host ranges (with numeric or alphabetic patterns)](https://docs.ansible.com/ansible/intro_inventory.html#hosts-and-groups).
With this configuration example:
```
Vagrant.configure("2") do |config|
config.vm.box = "ubuntu/trusty64"
config.vm.define "machine1"
config.vm.define "machine2"
config.vm.provision "ansible" do |ansible|
ansible.playbook = "playbook.yml"
ansible.groups = {
"group1" => ["machine1"],
"group2" => ["machine2"],
"group3" => ["machine[1:2]"],
"group4" => ["other_node-[a:d]"], # silly group definition
"all_groups:children" => ["group1", "group2"],
"group1:vars" => {"variable1" => 9,
"variable2" => "example"}
}
end
end
```
Vagrant would generate the following inventory file:
```
# Generated by Vagrant
machine1 ansible_ssh_host=127.0.0.1 ansible_ssh_port=2200 ansible_ssh_user='vagrant' ansible_ssh_private_key_file='/home/.../.vagrant/machines/machine1/virtualbox/private_key'
machine2 ansible_ssh_host=127.0.0.1 ansible_ssh_port=2222 ansible_ssh_user='vagrant' ansible_ssh_private_key_file='/home/.../.vagrant/machines/machine2/virtualbox/private_key'
[group1]
machine1
[group2]
machine2
[group3]
machine[1:2]
[group4]
other_node-[a:d]
[all_groups:children]
group1
group2
[group1:vars]
variable1=9
variable2=example
```
**Notes:**
- Prior to Vagrant 1.7.3, the `ansible_ssh_private_key_file` variable was not set in generated inventory, but passed as command line argument to `ansible-playbook` command.
- The generation of group variables blocks (e.g. `[group1:vars]`) is only possible since Vagrant 1.8.0. Note however that setting variables directly in the inventory is not the [preferred practice in Ansible](https://docs.ansible.com/intro_inventory.html#splitting-out-host-and-group-specific-data). If possible, group (or host) variables should be set in `YAML` files stored in the `group_vars/` or `host_vars/` directories in the playbook (or inventory) directory instead.
- Unmanaged machines and undefined groups are not added to the inventory, to avoid useless Ansible errors (e.g. *unreachable host* or *undefined child group*)
For example, `machine3` and `group3` in the example below would not be added to the generated inventory file:
```ruby
ansible.groups = {
"group1" => ["machine1"],
"group2" => ["machine2", "machine3"],
"all_groups:children" => ["group1", "group2", "group3"]
}
```
- [Host range patterns (numeric and alphabetic ranges)](https://docs.ansible.com/ansible/intro_inventory.html#hosts-and-groups) will not be validated by Vagrant. As of Vagrant 1.8.0, host range patterns will be added as group members to the inventory anyway, this might lead to errors in Ansible (e.g *unreachable host*).
### Static Inventory
The second option is for situations where you would like to have more control over the inventory management.
With the [`inventory_path`](/docs/provisioning/ansible_common.html#inventory_path) option, you can reference a specific inventory resource (e.g. a static inventory file, a [dynamic inventory script](https://docs.ansible.com/intro_dynamic_inventory.html) or even [multiple inventories stored in the same directory](https://docs.ansible.com/intro_dynamic_inventory.html#using-multiple-inventory-sources)). Vagrant will then use this inventory information instead of generating it.
A very simple 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"
```
**Notes:**
- The machine names in `Vagrantfile` and `ansible.inventory_path` files should correspond, unless you use `ansible.limit` option to reference the correct machines.
- The SSH host addresses (and ports) must obviously be specified twice, in `Vagrantfile` and `ansible.inventory_path` files.
- Sharing hostnames across Vagrant host and guests might be a good idea (e.g. with some Ansible configuration task, or with a plugin like [`vagrant-hostmanager`](https://github.com/smdahlen/vagrant-hostmanager)).
### The Ansible Configuration File
Certain settings in Ansible are (only) adjustable via a [configuration file](https://docs.ansible.com/intro_configuration.html), and you might want to ship such a file in your Vagrant project.
When shipping an Ansible configuration file it is good to know that:
- as of Ansible 1.5, the lookup order is the following:
- any path set as `ANSIBLE_CONFIG` environment variable
- `ansible.cfg` in the runtime working directory
- `.ansible.cfg` in the user home directory
- `/etc/ansible/ansible.cfg`
- Ansible commands don't look for a configuration file relative to the playbook file location (e.g. in the same directory)
- an `ansible.cfg` file located in the same directory as your `Vagrantfile` will be used by default.
- it is also possible to reference any other location with the [config_file](/docs/provisioning/ansible_common.html#config_file) provisioner option. In this case, Vagrant will set the `ANSIBLE_CONFIG` environment variable accordingly.