Ansible: is it possible to resize ext4 filesystem?

In order to make the task idempotent, add another task to first check for any unexpanded partitions. E.g., if you want the root partition to be at least 10 GB:

  - name: Assert root partition is expanded
    assert: { that: item.mount != '/' or item.size_total > 10737418240 } # 10 GB
    with_items: '{{ ansible_mounts }}'
    ignore_errors: yes
    register: expanded

NOTE: This task fails if the partition / is less than 10 GB.

Next, make the expansion task conditional on expanded|failed:

  - name: Expand partition
    command: parted /dev/mmcblk0 resizepart 2 15.5GB # NOTE: Assumes 16GB card
    when: expanded|failed
    notify: Expand filesystem

In my case, I'm expanding partition 2 on the block device /dev/mmcblk0 (for the Raspberry Pi). You should of course replace with the device names on your system.

Finally, notify triggers filesystem expansion:

  handlers:
  - name: Expand filesystem
    command: resize2fs /dev/mmcblk0p2

If you look at the source of the filesystem module as it currently stands, you can see that there doesn't seem to be anything you could use to resize a filesystem.

Thankfully, you have options: the command module and the shell module.

The command module is preferred over the shell module because it's not affected by the user environment, so I'll show you how to do it using the approach:

- name: "resize my ext4 filesystem, please"
  command: resize2fs /dev/sda1 
  sudo: True

where sda1 is your filesystem. If you need to enlarge your filesystem first, use the same approach, but make a call to fdisk (with the correct command line switches) instead.

Check man resize2fs for specific options for that command and the ansible documentation for more information, including parameterizing your command.

Don't know if it could help. But, since Ansible 2.0 there is resizefs option in the filesystem module that is false by default and that support ext4.

If yes, if the block device and filesystem size differ, grow the filesystem into the space. Supported for ext2, ext3, ext4, ext4dev, f2fs, lvm, xfs, vfat, swap filesystems.

https://docs.ansible.com/ansible/latest/modules/filesystem_module.html

- name: 'Extend the FS'
  filesystem:
    fstype: 'ext4'
    dev: '/dev/sda1'
    resizefs: yes