Detect and mount filesystem in Ansible

Question

I am new to ansible and try to detect a filesystem and than mount if present. I have gone through below links :-

1. https://docs.ansible.com/ansible/latest/modules/filesystem_module.html
2. https://docs.ansible.com/ansible/latest/modules/mount_module.html

I have attached a hard drive manually which is detected by command fdisk -l as "/dev/sdb". I want ansible code to detect and mount this filesystem on some location. While running the code "df -h" is not showing the mounted filesystem and not failing also. And even if I am listing all filesystem or mount point through ansible code, this filesystem (/dev/sdb) is not listing.

Code Snippet:

    - name: Create File System
      filesystem:
        fstype: ext4
        dev: "{{ mount_src }}"

    - name: Mount File System
      mount:
        path: "{{ mount_path }}"
        src: "{{ mount_src }}"
        fstype: ext4
        state: mounted

Thanks in advance and any help would be appreciated.

Answer 1

The play below creates a list of mounted devices. When mount_src is not mounted, the filesystem is created, and mount_src is mounted to mount_path.

- hosts: localhost

  vars:

    mount_src: /dev/sdb
    mount_path: /export
    mounted_devices: "{{ ansible_mounts | map(attribute='device') }}"

  tasks:

    - name: Create File System
      filesystem:
        fstype: ext4
        dev: "{{ mount_src }}"
      when: mount_src not in mounted_devices

    - name: Mount File System
      mount:
        path: "{{ mount_path }}"
        src: "{{ mount_src }}"
        fstype: ext4
        state: mounted
      when: mount_src not in mounted_devices

^{(not tested)}

Ansible does not gather facts about the block devices. In Linux, it's possible to use the command lsblk instead. For example,

- hosts: localhost

  vars:

    block_devices: "{{ results.stdout_lines }}"

  tasks:

    - name: Get list of block devices
      command: 'lsblk -lno NAME'
      register: results

    - debug:
        var: block_devices

gives

ok: [127.0.0.1] => 
  block_devices:
  - sda
  - sda1
  - sda2
  - sda3
  - sda5
  - sdb
  - sdb1
  - sdb9
  - mmcblk0
  - mmcblk0p1

---

Update

You can test mounted partitions in addition to testing that a device is not among mounted devices. The test match:

match succeeds if it finds the pattern at the beginning of the string

- hosts: localhost

  vars:

    mount_src: /dev/sdb
    mount_path: /export
    mounted_devices: "{{ ansible_mounts | map(attribute='device') }}"
    mounted_partitions: "{{ mounted_devices | select('match', mount_src) }}"

  tasks:

    - name: Get mounted devices
      setup:
        gather_subset: mounts

    - debug:
        var: mounted_devices
    - debug:
        var: mounted_partitions

    - name: Create and mount files system
      when:
        - mount_src not in mounted_devices
        - mounted_partitions | length == 0
      block:

        - name: Create File System
          filesystem:
            dev: "{{ mount_src }}"
            fstype: ext4

        - name: Mount File System
          mount:
            src: "{{ mount_src }}"
            path: "{{ mount_path }}"
            fstype: ext4
            state: mounted

^{(not tested)}