Get list of filesystems and mountpoints using Ansible - ansible

Question

I'm struggling to get a solution for this:
I need to create a CSV file with all the filesystems and respective mountpoints on every server, using Ansible.
I managed to create a Python script that displays the information I want:
hostname,filesystem,mountpoint
Works beautifully on every server EXCEPT those where Python is not installed :)
- name: Get filesystem data
shell: python /tmp/filesystem.py
register: get_fs_data
become: yes
become_method: sudo
become_user: root
- set_fact:
filesystem_data: "{{ get_fs_data.stdout }}"
when: get_fs_data.rc == 0
So, my question is ...
How can this be achieved without the usage of that Python script?
I basically want to build a similar list like the one above (hostname, filesystem, mountpoint).
I could execute something like:
df --type=xfs -h --output=source,target
But the output has several lines, one for each file system, and I'm not sure how to handle it on Ansible directly.

Answer 1

There are more options.
See Ansible collect df output and convert to dictionary from set_fact how to parse the output of df
The simplest option is to use the setup module parameter gather_subset: mounts. Unfortunately, this doesn't work properly for all OS. There is no problem with Linux. The playbook
- hosts: localhost
gather_facts: false
tasks:
- setup:
gather_subset:
- distribution
- mounts
- debug:
var: ansible_distribution
- debug:
var: ansible_mounts
gives (abridged)
TASK [debug] *********************************************************************************
ok: [localhost] =>
ansible_distribution: Ubuntu
TASK [debug] *********************************************************************************
ok: [localhost] =>
ansible_mounts:
- block_available: 2117913
block_size: 4096
block_total: 10013510
block_used: 7895597
device: /dev/nvme0n1p6
fstype: ext4
inode_available: 1750968
inode_total: 2564096
inode_used: 813128
mount: /
options: rw,relatime,errors=remount-ro
size_available: 8674971648
size_total: 41015336960
uuid: 505b60e7-509f-46e6-b833-f388df6bb9f0
...
But the same playbook on FreeBSD shows nothing
TASK [debug] *********************************************************************************
ok: [test_11] =>
ansible_distribution: FreeBSD
TASK [debug] *********************************************************************************
ok: [test_11] =>
ansible_mounts: []
If gather_subset: mounts works on your systems the report is simple. For example, the task below
- copy:
dest: /tmp/ansible_df_all.csv
content: |
hostname,filesystem,mountpoint
{% for hostname in ansible_play_hosts %}
{% for mount in hostvars[hostname]['ansible_mounts'] %}
{{ hostname }},{{ mount.device }},{{ mount.mount}}
{% endfor %}
{% endfor %}
run_once: true
delegate_to: localhost
will create the file at the controller
shell> cat /tmp/ansible_df_all.csv
hostname,filesystem,mountpoint
localhost,/dev/nvme0n1p6,/
localhost,/dev/nvme0n1p7,/export
localhost,/dev/nvme0n1p2,/boot/efi

Answer 2

Q: Get list of filesystems and mountpoints using Ansible and df without Python installed
As already mentioned within the other answer, there are many options possible.
the output has several lines, one for each file system, and I'm not sure how to handle it on Ansible directly
The data processing can be done on Remote Nodes (data pre-processing, data cleansing), Control Node (data post-processing) or partially on each of them.
Whereby I prefer the answer of #Vladimir Botka and recommend to use it since the data processing is done on the Control Node and in Python
How can this be achieved without the usage of that Python script? (annot.: or any Python installed on the Remote Node)
a lazy approach could be
---
- hosts: test
become: false
gather_facts: false # is necessary because setup.py depends on Python too
tasks:
- name: Gather raw 'df' output with pre-processing
raw: "df --type=ext4 -h --output=source,target | tail -n +2 | sed 's/ */,/g'"
register: result
- name: Show result as CSV
debug:
msg: "{{ inventory_hostname }},{{ item }}"
loop_control:
extended: true
label: "{{ ansible_loop.index0 }}"
loop: "{{ result.stdout_lines }}"
resulting into an output of
TASK [Show result as CSV] *************
ok: [test.example.com] => (item=0) =>
msg: test.example.com,/dev/sda3,/
ok: [test.example.com] => (item=1) =>
msg: test.example.com,/dev/sda4,/tmp
ok: [test.example.com] => (item=2) =>
msg: test.example.com,/dev/sdc1,/var
ok: [test.example.com] => (item=3) =>
msg: test.example.com,/dev/sda2,/boot
As noted before, the data pre-processing parts
Remove first line from output via | tail -n +2
Remove multiple whitepspaces and replace via | sed 's/ */,/g'
could be processed in Ansible and Python on the Control Node, in example
Remove first line in stdout_lines (annot.: and as a general approach for --no-headers even for commands which do not provide such)
Simply split item on space and re-join all elements of the list with comma (,) via {{ item | split | join(',') }}
- name: Gather raw 'df' output without pre-processing
raw: "df --type=ext4 -h --output=source,target"
register: result
- name: Show result as CSV
debug:
msg: "{{ inventory_hostname }},{{ item | split | join(',')}}"
loop_control:
extended: true
label: "{{ ansible_loop.index0 }}"
loop: "{{ result.stdout_lines[1:] }}" # with --no-headers
resulting into the same output as before.
Documentation Links
for Ansible
raw module - Executes a low-down and dirty command
This is useful and should only be done in a few cases ... speaking to any devices such as routers that do not have any Python installed. Arguments given to raw are run directly through the configured remote shell. Standard output, error output and return code are returned when available.
Whats the difference between Ansible raw, shell and command?
The command and shell module, as well gather_facts (annot.: setup.py) depend on a properly installed Python interpreter on the Remote Node(s). If that requirement isn't fulfilled one may experience errors
Extended loop variables
split filter – split a string into a list
Using filters to manipulate data - Manipulating strings, see split and join
Information about Ansible: magic variables
You can use the magic variable inventory_hostname, the name of the host as configured in your inventory, as an alternative to ansible_hostname when fact-gathering is disabled. If you have a long FQDN, you can use inventory_hostname_short, which contains the part up to the first period, without the rest of the domain.
How Ansible gather_facts and sets variables?
and Linux commands
How to omit heading in df command?
How to strip multiple spaces to one using sed?
Further Reading
cli_parse module – Parse cli output or text using a variety of parsers
Re: Wishlist: --no-header option for df