The yaml stdout callback plugin is an ansible plugin to change the output in yaml format.

To install it we need to run the following command:

ansible-galaxy collection install community.general

Let’s try to run simple an ansible playbook before enabling the plugin (The stdout will be in JSON format):

PLAY [Dummy VM checks] *****************************************************************************************************************

TASK [Gathering Facts] *****************************************************************************************************************
ok: [192.168.1.16]

TASK [Checking VM started!] ************************************************************************************************************
ok: [192.168.1.16] => {
    "msg": "Staring process...."
}

TASK [Show hostname] *******************************************************************************************************************
changed: [192.168.1.16]

TASK [Classify hosts depending on their OS distribution] *******************************************************************************
changed: [192.168.1.16]

TASK [Operating Systems] ***************************************************************************************************************
ok: [192.168.1.16] => {
    "msg": "The operating system is Fedora"
}

TASK [Hostname] ************************************************************************************************************************
ok: [192.168.1.16] => {
    "msg": "The operating system is linux-lab"
}

TASK [Facts] ***************************************************************************************************************************
ok: [192.168.1.16] => {
    "msg": [
        {
            "block_available": 2029793,
            "block_size": 4096,
            "block_total": 3669248,
            "block_used": 1639455,
            "device": "/dev/sda3",
            "fstype": "btrfs",
            "inode_available": 0,
            "inode_total": 0,
            "inode_used": 0,
            "mount": "/",
            "options": "rw,seclabel,relatime,compress=zstd:1,ssd,space_cache=v2,subvolid=257,subvol=/root,bind",
            "size_available": 8314032128,
            "size_total": 15029239808,
            "uuid": "de0fa6cc-f7f2-41ad-96a3-0215b13371ef"
        },
        {
            "block_available": 2029793,
            "block_size": 4096,
            "block_total": 3669248,
            "block_used": 1639455,
            "device": "/dev/sda3",
            "fstype": "btrfs",
            "inode_available": 0,
            "inode_total": 0,
            "inode_used": 0,
            "mount": "/home",
            "options": "rw,seclabel,relatime,compress=zstd:1,ssd,space_cache=v2,subvolid=256,subvol=/home,bind",
            "size_available": 8314032128,
            "size_total": 15029239808,
            "uuid": "de0fa6cc-f7f2-41ad-96a3-0215b13371ef"
        },
        {
            "block_available": 152284,
            "block_size": 4096,
            "block_total": 249195,
            "block_used": 96911,
            "device": "/dev/sda2",
            "fstype": "ext4",
            "inode_available": 65135,
            "inode_total": 65536,
            "inode_used": 401,
            "mount": "/boot",
            "options": "rw,seclabel,relatime",
            "size_available": 623755264,
            "size_total": 1020702720,
            "uuid": "0a6142b0-df7e-441c-896d-38133b3e37d1"
        }
    ]
}

TASK [Get uptime information] **********************************************************************************************************
changed: [192.168.1.16]

TASK [Print return information from the previous task] *********************************************************************************
skipping: [192.168.1.16]

TASK [Ansible | Run a simple post task] ************************************************************************************************
ok: [192.168.1.16] => {
    "msg": "All task have been performed"
}

PLAY RECAP *****************************************************************************************************************************
192.168.1.16               : ok=9    changed=3    unreachable=0    failed=0    skipped=1    rescued=0    ignored=0  

To enable/configure the yaml stdout callback plugin we need to add the following lines at the ansible configuration file (stdout callback plugin):

sudo vim /etc/ansible/ansible.cfg

[defaults]
stdout_callback = community.general.yaml

Then after running again the same ansible playbook we must be able to see the stdout in yaml format:

PLAY [Dummy VM checks] *****************************************************************************************************************

TASK [Gathering Facts] *****************************************************************************************************************
ok: [192.168.1.16]

TASK [Checking VM started!] ************************************************************************************************************
ok: [192.168.1.16] => 
  msg: Staring process....

TASK [Show hostname] *******************************************************************************************************************
changed: [192.168.1.16]

TASK [Classify hosts depending on their OS distribution] *******************************************************************************
changed: [192.168.1.16]

TASK [Operating Systems] ***************************************************************************************************************
ok: [192.168.1.16] => 
  msg: The operating system is Fedora

TASK [Hostname] ************************************************************************************************************************
ok: [192.168.1.16] => 
  msg: The operating system is linux-lab

TASK [Facts] ***************************************************************************************************************************
ok: [192.168.1.16] => 
  msg:
  - block_available: 2029787
    block_size: 4096
    block_total: 3669248
    block_used: 1639461
    device: /dev/sda3
    fstype: btrfs
    inode_available: 0
    inode_total: 0
    inode_used: 0
    mount: /
    options: rw,seclabel,relatime,compress=zstd:1,ssd,space_cache=v2,subvolid=257,subvol=/root,bind
    size_available: 8314007552
    size_total: 15029239808
    uuid: de0fa6cc-f7f2-41ad-96a3-0215b13371ef
  - block_available: 2029787
    block_size: 4096
    block_total: 3669248
    block_used: 1639461
    device: /dev/sda3
    fstype: btrfs
    inode_available: 0
    inode_total: 0
    inode_used: 0
    mount: /home
    options: rw,seclabel,relatime,compress=zstd:1,ssd,space_cache=v2,subvolid=256,subvol=/home,bind
    size_available: 8314007552
    size_total: 15029239808
    uuid: de0fa6cc-f7f2-41ad-96a3-0215b13371ef
  - block_available: 152284
    block_size: 4096
    block_total: 249195
    block_used: 96911
    device: /dev/sda2
    fstype: ext4
    inode_available: 65135
    inode_total: 65536
    inode_used: 401
    mount: /boot
    options: rw,seclabel,relatime
    size_available: 623755264
    size_total: 1020702720
    uuid: 0a6142b0-df7e-441c-896d-38133b3e37d1

TASK [Get uptime information] **********************************************************************************************************
changed: [192.168.1.16]

TASK [Print return information from the previous task] *********************************************************************************
skipping: [192.168.1.16]

TASK [Ansible | Run a simple post task] ************************************************************************************************
ok: [192.168.1.16] => 
  msg: All task have been performed

PLAY RECAP *****************************************************************************************************************************
192.168.1.16               : ok=9    changed=3    unreachable=0    failed=0    skipped=1    rescued=0    ignored=0