ansible-examples

Project with some examples of how to use Ansible.

To run these examples will need to have the ansible tool installed. To install please follow the official doc.

Examples

• Simple Ansible playbooks
  • Playbook file
  • Inventory file

Simple Ansible playbooks

Ansible example of how to works with Ansible playbooks. This example shows how to:

• Work with hosts and variables
• Work with a simple playbook
• Add conditional tasks on playbooks

This example the project has two files:

• a inventory file called hosts.

• a playbook example file called playbook-demo.yml.

Inventory file: hosts

The inventory file on this project will just be a set of hosts in a couple of groups. Each host is uniquely named so that we can distinguish it in the output.

To run this example is defined too a variable for all the hosts that instructs Ansible to connect to these fake hosts locally.

[all:vars]
ansible_connection=local

This file is needed in order to play the ansible playbook example.

Playbook example file: playbook-demo.yml

Simple example of an Ansible playbook with some debug tasks that only print some debug messages. This playbook uses the inventory file playbook-demo.yml

Running the example

To run the ansible is needed to tell Ansible playbook the inventory file to use and the playbook file to parse that in this case the hosts file.

The Inventory is provided with the -i argument.

To run this example, on the root of this project run:

 ansible-playbook -i inventories/hosts playbooks/playbook-demo.yml

If everything works properly each play is displayed on screen and as each host completes each task, the result is displayed on screen like the following result:

➜  ansible-examples git:(master) ✗  ansible-playbook -i  invetories/hosts playbooks/playbook-demo.yml 

PLAY [Do a demo 1] **************************************************************************************

TASK [Gathering Facts] **********************************************************************************
ok: [host3]
ok: [host2]
ok: [host1]

TASK [demo task 1] **************************************************************************************
ok: [host1] => {
    "msg": "this is task 1"
}
ok: [host2] => {
    "msg": "this is task 1"
}
ok: [host3] => {
    "msg": "this is task 1"
}

TASK [demo task 2] **************************************************************************************
ok: [host1] => {
    "msg": "this is task 2"
}
ok: [host2] => {
    "msg": "this is task 2"
}
ok: [host3] => {
    "msg": "this is task 2"
}

PLAY [Do another demo 1] ********************************************************************************

TASK [Gathering Facts] **********************************************************************************
ok: [host4]
ok: [host6]
ok: [host5]

TASK [demo task 3] **************************************************************************************
ok: [host4] => {
    "msg": "this is task 3"
}
ok: [host5] => {
    "msg": "this is task 3"
}
ok: [host6] => {
    "msg": "this is task 3"
}

TASK [demo task 4] **************************************************************************************
ok: [host4] => {
    "msg": "this is task 4"
}
ok: [host5] => {
    "msg": "this is task 4"
}
ok: [host6] => {
    "msg": "this is task 4"
}

PLAY [Do another demo 2] ********************************************************************************

TASK [Gathering Facts] **********************************************************************************
ok: [host8]
ok: [host9]
ok: [host7]

TASK [demo task 5] **************************************************************************************
fatal: [host7]: FAILED! => {"changed": false, "msg": "this is task 5"}
skipping: [host8]
skipping: [host9]

TASK [demo task 6] **************************************************************************************
ok: [host8] => {
    "msg": "this is task 6"
}
ok: [host9] => {
    "msg": "this is task 6"
}

PLAY [Do another demo 3] ********************************************************************************

TASK [Gathering Facts] **********************************************************************************
ok: [host10]

TASK [demo task 7] **************************************************************************************
skipping: [host10]

TASK [demo task 8] **************************************************************************************
ok: [host10] => {
    "msg": "this is task 8"
}

PLAY [Do another demo 3] ********************************************************************************

TASK [Gathering Facts] **********************************************************************************
ok: [host11]

TASK [demo task 7] **************************************************************************************
fatal: [host11]: FAILED! => {"changed": false, "msg": "this is task 7"}
	to retry, use: --limit @/home/coderade/repo/personal/ansible-examples/playbooks/playbook-demo.retry

PLAY RECAP **********************************************************************************************
host1                      : ok=3    changed=0    unreachable=0    failed=0   
host10                     : ok=2    changed=0    unreachable=0    failed=0   
host11                     : ok=1    changed=0    unreachable=0    failed=1   
host2                      : ok=3    changed=0    unreachable=0    failed=0   
host3                      : ok=3    changed=0    unreachable=0    failed=0   
host4                      : ok=3    changed=0    unreachable=0    failed=0   
host5                      : ok=3    changed=0    unreachable=0    failed=0   
host6                      : ok=3    changed=0    unreachable=0    failed=0   
host7                      : ok=1    changed=0    unreachable=0    failed=1   
host8                      : ok=2    changed=0    unreachable=0    failed=0   
host9                      : ok=2    changed=0    unreachable=0    failed=0   

Ad hoc examples

Examples of ad hoc taks

Run a command in each host of an inventory

The bellow examples show how to run a command in each host of an inventory. In this example the command is asking the ansible and the Linux versions:

ansible -i inventories/webapp-inventory web -m command -a "ansible --version"

ansible -i inventories/webapp-inventory host1 -m command -a "uname -r"

Debug message

This example shows how to run a debug message in each item of an inventory:

ansible -i inventories/webapp-inventory web -m debug -a "msg='shutdown -r now'" 

Instaling some packages on the hosts

This example shows how to install a linux module using the apt Ansible's module.

ansible -i inventories/webapp-inventory web -m apt -a "name=python-selinux state=present" -f 1 -b

-f 1 => forks limit to 1 (maximum number of concurret hosts) -b => privilege escalation (run as sudo)

Copying files to hosts example

This example shows how to copy files using the copy module:

ansible -i inventories/webapp-inventory web -m copy -a "src=.keep dest=/tmp/.keep"


ansible -i inventories/webapp-inventory host1 -m command -a "uname -r"