Problem while comparing two arrays due to unecessary chars

Question

I have to two array from mysql query and I want to make a host comparison. For example, the result of mysql result is like list1 & list2.

- name:
  set_fact:
    list1:
      - host: '[\"X.XXX.XX.XXX\"]'
        username: username1
      - host: '[\"X.XXX.XX.XXX\"]'
        username: username2
      - host: '[\"X.XXX.XX.XXX\"]'
        username: username3
      - host: 
        - '[\"XX.XXX.XX.XXX\"]' 
        - '[\"XX.X.X.XXX\"]'
        username: username4
      - host: '[\"XX.X.X.XXX\"]'
        username: username5
      - host: '[\"localhost\"]'
        username: username6
      - host: '[\"XX.XXX.XX.XXX\"]'
        username: username7
    list2: 
      - host: 'X.XXX.XX.XXX'
        username: username1
      - host: 'localhost'
        username: username2
      - host: 'XX.XXX.XX.XXX'
        username: username3
      - host: 'localhost'
        username: username4
      - host: 'XX.X.X.XXX'
        username: username5
  tags: [diff]

As you see, list2 from mysql query sent back hosts with some unecessary chars and I want to remove them because when making the comparison, the condition is false.

- name: Comparison of two lists
  debug: 
    msg: "{{ item.0.username }}({{ item.0.host }}) == {{ item.1.username }}({{ item.1.host }}) {{ item.0.username == item.1.username }}"
  loop: "{{ list1 | product(list2) | list }}"
  when: 
    - "{{ item.0.host == item.1.host }} == True"
  register: output
  tags: [diff]

Here is the output from Ansible :

skipping: [staging1-sql0] => (item=[{'host': '[\\"X.XXX.XX.XXX\\"]', 'username': 'username1'}, {'host': 'X.XXX.XX.XXX', 'username': 'username1'}]) 
skipping: [staging1-sql0] => (item=[{'host': '[\\"X.XXX.XX.XXX\\"]', 'username': 'username2'}, {'host': 'localhost', 'username': 'username2'}]) 
skipping: [staging1-sql0] => (item=[{'host': '[\\"X.XXX.XX.XXX\\"]', 'username': 'username3'}, {'host': 'XX.XXX.XX.XXX', 'username': 'username3'}])

How can I fix this ?

guistela · Accepted Answer · 2021-03-30T05:42:29.667

Are you using other lists or this should be loop: "{{ list1 | product(list2) | list }}" instead?

I tried this code and it worked:

- hosts: localhost
  gather_facts: no

  tasks:

  - name:
    set_fact:
      list1:
        - host: '[\"X.XXX.XX.XXX\"]'
          username: username1
        - host: '[\"X.XXX.XX.XXX\"]'
          username: username2
        - host: '[\"X.XXX.XX.XXX\"]'
          username: username3
        - host: 
          - '[\"XX.XXX.XX.XXX\"]' 
          - '[\"XX.X.X.XXX\"]'
          username: username4
        - host: '[\"XX.X.X.XXX\"]'
          username: username5
        - host: '[\"localhost\"]'
          username: username6
        - host: '[\"XX.XXX.XX.XXX\"]'
          username: username7
      list2: 
        - host: 'X.XXX.XX.XXX'
          username: username1
        - host: 'localhost'
          username: username2
        - host: 'XX.XXX.XX.XXX'
          username: username3
        - host: 'localhost'
          username: username4
        - host: 'XX.X.X.XXX'
          username: username5
    tags: [diff]

  - name: Comparison of two lists
    debug: 
      msg:
        - "{{ list1_username }}{{ list1_host }} == {{ list2_username}}({{ list2_host}}) {{ list1_username == list2_username }}"
    loop: "{{ list1 | product(list2) | list }}"
    when: list1_host == list2_host
    register: output
    tags: [diff]
    vars:
      list1_host: "{{ (item.0.host|replace('[\\\"','')|replace('\\\"]','')) }}"
      list1_username: "{{ item.0.username }}"
      list2_host: "{{ item.1.host }}"
      list2_username: "{{ item.1.username }}"

Hints:

No need to use jinja templating in when clauses.
Sometimes it's better to create arguments to the task to clarify variable's attributes inside a looping
Instead of using debug, you can set the information to a variable or append to a list
Be careful to always test your code with better data variation and use block and rescue to prevent fatal runtime errors.

I don't really know what are you doing but you can improve you code by using select filter, including a task file while looping through the first list and then comparing with the second one, using templates and other things... Share the whole case and we can help better.

Sorry my bad, yes it should be `loop: "{{ list1 | product(list2) | list }}"` Indeed, my code isn't that good. I'm currently working to improve it. What I exactly want to do by doing this, is to create a playbook "Users to remove" that will remove users. Basically, I have two servers : Ansible et MySQL. I extract informations such as Username and Ip and I compare them to find the username and ip that is my Ansible server, but not in my MySQL server. I have to make an optimal playbook for the case that a username has several ips. Thank you for the code I'll try it rn and let you know it works. — Mansour NDIAYE, Apr 02 '21 at 11:14

Problem while comparing two arrays due to unecessary chars

1 Answers1