Check if a file has certain strings

I have some files (file1), in some servers (group: myservers), which should look like this:

search www.mysebsite.com
nameserver 1.2.3.4
nameserver 1.2.3.5

This is an example of what this file should look like: The first line is mandatory ("search www.mysebsite.com"). The second and the third lines are mandatory as well, but the ips can change (although they should all be like this: ...).

I've being researching to implement some tasks using Ansible to check if the files are properly configured. I don't want to change any file, only check and output if the files are not ok or not. I know I can use ansible.builtin.lineinfile to check it, but I still haven't managed to find out how to achieve this. Can you help please?

Solution

For example, given the inventory

shell> cat hosts
[myservers]
test_11
test_13

Create a dictionary of what you want to audit

  audit:
    files:
      /etc/resolv.conf:
        patterns:
          - '^search example.com$'
          - '^nameserver \d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$'
      /etc/rc.conf:
        patterns:
          - '^sshd_enable="YES"$'
          - '^syslogd_flags="-ss"$'

^{Note: The order of the patterns is mandatory. The tests will succeed if the first two lines of the files match the sequence of patterns. For example,
shell> cat /etc/rc.conf
sshd_enable="YES"
syslogd_flags="-ss"

shell> cat /etc/resolv.conf
search example.com
nameserver 10.1.0.1}

Declare the directory at the controller where the files will be stored

  my_dest: /tmp/ansible/myservers

fetch the files

    - fetch:
        src: "{{ item.key }}"
        dest: "{{ my_dest }}"
      loop: "{{ audit.files|dict2items }}"

Take a look at the fetched files

shell> tree /tmp/ansible/myservers
/tmp/ansible/myservers
├── test_11
│   └── etc
│       ├── rc.conf
│       └── resolv.conf
└── test_13
    └── etc
        ├── rc.conf
        └── resolv.conf

4 directories, 4 files

Audit the files. Create the dictionary host_files_results in the loop

    - set_fact:
        host_files_results: "{{ host_files_results|default({})|
                                combine(host_file_dict|from_yaml) }}"
      loop: "{{ audit.files|dict2items }}"
      loop_control:
        label: "{{ item.key }}"
      vars:
        host_file_path: "{{ my_dest }}/{{ inventory_hostname }}/{{ item.key }}"
        host_file_lines: "{{ lookup('file', host_file_path).splitlines() }}"
        host_file_result: |
          [{% for pattern in item.value.patterns %}
          {{ host_file_lines[loop.index0] is regex pattern }},
          {% endfor %}]
        host_file_dict: "{ {{ item.key }}: {{ host_file_result|from_yaml is all }} }"

gives

ok: [test_11] => 
  host_files_results:
    /etc/rc.conf: true
    /etc/resolv.conf: true
ok: [test_13] => 
  host_files_results:
    /etc/rc.conf: true
    /etc/resolv.conf: true

Declare the dictionary audit_files that aggregates host_files_results

  audit_files: "{{ dict(ansible_play_hosts|
                        zip(ansible_play_hosts|
                            map('extract', hostvars, 'host_files_results'))) }}"

gives

  audit_files:
    test_11:
      /etc/rc.conf: true
      /etc/resolv.conf: true
    test_13:
      /etc/rc.conf: true
      /etc/resolv.conf: true

Evaluate the audit results

    - block:
        - debug:
            var: audit_files
        - assert:
            that: "{{ audit_files|json_query('*.*')|flatten is all }}"
            fail_msg: "[ERR] Audit of files failed. [TODO: list failed]"
            success_msg: "[OK]  Audit of files passed."
      run_once: true

gives

 msg: '[OK]  Audit of files passed.'

^{Example of a complete playbook for testing
- hosts: myservers

vars:

my_dest: /tmp/ansible/myservers

audit:
files:
/etc/resolv.conf:
patterns:
- '^search example.com$'
- '^nameserver \d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$'
/etc/rc.conf:
patterns:
- '^sshd_enable="YES"$'
- '^syslogd_flags="-ss"$'

audit_files: "{{ dict(ansible_play_hosts|
zip(ansible_play_hosts|
map('extract', hostvars, 'host_files_results'))) }}"

tasks:

- fetch:
src: "{{ item.key }}"
dest: "{{ my_dest }}"
loop: "{{ audit.files|dict2items }}"
loop_control:
label: "{{ item.key }}"

- set_fact:
host_files_results: "{{ host_files_results|default({})|
combine(host_file_dict|from_yaml) }}"
loop: "{{ audit.files|dict2items }}"
loop_control:
label: "{{ item.key }}"
vars:
host_file_path: "{{ my_dest }}/{{ inventory_hostname }}/{{ item.key }}"
host_file_lines: "{{ lookup('file', host_file_path).splitlines() }}"
host_file_result: |
[{% for pattern in item.value.patterns %}
{{ host_file_lines[loop.index0] is regex pattern }},
{% endfor %}]
host_file_dict: "{ {{ item.key }}: {{ host_file_result|from_yaml is all }} }"

- debug:
var: host_files_results

- block:
- debug:
var: audit_files
- assert:
that: "{{ audit_files|json_query('*.*')|flatten is all }}"
fail_msg: "[ERR] Audit of files failed. [TODO: list failed]"
success_msg: "[OK] Audit of files passed."
run_once: true}