Question posted in Json
Our archive of expertly curated questions and answers provides insights and solutions to common problems related to this popular data interchange format. From parsing and manipulating JSON data to integrating it with various programming languages and web services, our archive has got you covered. Start exploring today and take your JSON skills to the next level

Modify .json file using Anisble

Sihabul
December 27, 2022
316 views
0 votes
2 Answers

My file structure is like below

[root@test exim]# cat exim.json
{
    "general": {
        "max_hourly_email": 0,
        "max_notify_email": 0,
        "enable_mail_retry": "1",
        "mail_retry": 15,
        "enable_roundcube": "1",
        "default_quota_val": 32768,
        "default_quota": "1",
        "eximmailtrap": "1",
        "no_local_emailing": "0",
        "dkim_selector": "x",
        "disable_ipv6": "0",
        "custom_mailips": "0",
        "message_linelength_limit": 2048

I want to change the value of "max_hourly_email" and "max_notify_email"

**I am trying to change the valued using following method:
**

- name: Set Max hourly emails per domain
  lineinfile:
    path: /var/webuzo/conf/exim/exim.json
    regexp: 'max_hourly_email'
    line: '        "max_hourly_email": 200,'
    state: present

It is changing the value but breaking the file sturcture like below

[root@test exim]# cat exim.json
{
    "general": {
**"max_hourly_email": 200,**
        "max_notify_email": 0,
        "enable_mail_retry": "1",
        "mail_retry": 15,
        "enable_roundcube": "1",
        "default_quota_val": 32768,
        "default_quota": "1",
        "eximmailtrap": "1",
        "no_local_emailing": "0",
        "dkim_selector": "x",
        "disable_ipv6": "0",
        "custom_mailips": "0",
        "message_linelength_limit": 2048

How may I change the values using ansible without breaking the structure.
Thanks.

Answers

Given the file with the sorted dictionary for simpler comparison

shell> cat exim.json
{
    "general": {
        "custom_mailips": "0",
        "default_quota": "1",
        "default_quota_val": 32768,
        "disable_ipv6": "0",
        "dkim_selector": "x",
        "enable_mail_retry": "1",
        "enable_roundcube": "1",
        "eximmailtrap": "1",
        "mail_retry": 15,
        "max_hourly_email": 0,
        "max_notify_email": 0,
        "message_linelength_limit": 2048,
        "no_local_emailing": "0"
    }
}

lineinfile

Create a dictionary with the updates. For example, if you want to keep the double quotes make them part of the string

  update:
    general:
      max_hourly_email: 200
      enable_mail_retry: '"3"'
      test: 9

The task below will update existing keys, but won’t add a new one

    - lineinfile:
        backrefs: true
        path: "{{ my_file }}"
        regexp: '^(.*){{ item.key }}(.*):s+(.*)$'
        line: '1{{ item.key }}2: {{ item.value }},'
      loop: "{{ update.general|dict2items }}"

gives when running with options –check –diff

TASK [lineinfile] ****************************************************************************
--- before: /export/scratch/tmp7/test-117/exim.json (content)
+++ after: /export/scratch/tmp7/test-117/exim.json (content)
@@ -9,7 +9,7 @@
         "enable_roundcube": "1",
         "eximmailtrap": "1",
         "mail_retry": 15,
-        "max_hourly_email": 0,
+        "max_hourly_email": 200,
         "max_notify_email": 0,
         "message_linelength_limit": 2048,
         "no_local_emailing": "0"

changed: [localhost] => (item={'key': 'max_hourly_email', 'value': 200})
--- before: /export/scratch/tmp7/test-117/exim.json (content)
+++ after: /export/scratch/tmp7/test-117/exim.json (content)
@@ -5,7 +5,7 @@
         "default_quota_val": 32768,
         "disable_ipv6": "0",
         "dkim_selector": "x",
-        "enable_mail_retry": "1",
+        "enable_mail_retry": "3",
         "enable_roundcube": "1",
         "eximmailtrap": "1",
         "mail_retry": 15,

changed: [localhost] => (item={'key': 'enable_mail_retry', 'value': '"3"'})
ok: [localhost] => (item={'key': 'test', 'value': 9})

template

There is a more flexible option of combining the dictionaries and using a template. Remove the extra quotation

  update:
    general:
      max_hourly_email: 200
      enable_mail_retry: "3"
      test: 9

combine the dictionaries

    - copy:
        dest: "{{ playbook_dir }}/exim.json"
        content: |
          {{ orig|combine(update, recursive=true)|to_nice_json }}
      vars:
        orig: "{{ lookup('file', my_file)|from_yaml }}"

gives when running with options –check –diff

TASK [copy] **********************************************************************************
--- before: /export/scratch/tmp7/test-117/exim.json
+++ after: /home/admin/.ansible/tmp/ansible-local-888558_ztunphb/tmp9b2vctgc
@@ -5,13 +5,14 @@
         "default_quota_val": 32768,
         "disable_ipv6": "0",
         "dkim_selector": "x",
-        "enable_mail_retry": "1",
+        "enable_mail_retry": "3",
         "enable_roundcube": "1",
         "eximmailtrap": "1",
         "mail_retry": 15,
-        "max_hourly_email": 0,
+        "max_hourly_email": 200,
         "max_notify_email": 0,
         "message_linelength_limit": 2048,
-        "no_local_emailing": "0"
+        "no_local_emailing": "0",
+        "test": 9
     }
 }

changed: [localhost]

Notes

Example of a complete playbook for testing

- hosts: localhost

  vars:

    my_file: "{{ playbook_dir }}/exim.json"
    
  tasks:

    - lineinfile:
        backrefs: true
        path: "{{ my_file }}"
        regexp: '^(.*){{ item.key }}(.*):s+(.*)$'
        line: '1{{ item.key }}2: {{ item.value }},'
      loop: "{{ update.general|dict2items }}"
      when: iter|d(true)|bool
      vars:
        update:
          general:
            max_hourly_email: 200
            enable_mail_retry: '"3"'
            test: 9

    - copy:
        dest: "{{ my_file }}"
        content: |
          {{ orig|combine(update, recursive=true)|to_nice_json }}
      when: not iter|d(true)|bool
      vars:
        orig: "{{ lookup('file', my_file)|from_yaml }}"
        update:
          general:
            max_hourly_email: 200
            enable_mail_retry: "3"
            test: 9

Above answer by Vladimir is quite comprehensive , adding to above I have written a simple playbook using jinja expression which is easy to understand.

exim.j2

{
    "general": {
        "custom_mailips": "0",
        "default_quota": "1",
        "default_quota_val": 32768,
        "disable_ipv6": "0",
        "dkim_selector": "x",
        "enable_mail_retry": "1",
        "enable_roundcube": "1",
        "eximmailtrap": "1",
        "mail_retry": 15,
        "max_hourly_email": "{{ max_hourly_email }}",
        "max_notify_email": "{{ max_notify_email }}",
        "message_linelength_limit": 2048,
        "no_local_emailing": "0"
    }
}

Using the above jinja file in the below playbook

---
- name: Set variable in jinja file
  hosts: localhost
  become: true
  vars:
    max_hourly_email: 200
    max_notify_email: [email protected]
  tasks:
    - name: Deploy the file
      template:
        src: exim.j2
        dest: final.txt

Below is the output final.txt that is produced as desired.

{
    "general": {
        "custom_mailips": "0",
        "default_quota": "1",
        "default_quota_val": 32768,
        "disable_ipv6": "0",
        "dkim_selector": "x",
        "enable_mail_retry": "1",
        "enable_roundcube": "1",
        "eximmailtrap": "1",
        "mail_retry": 15,
        "max_hourly_email": "200",
        "max_notify_email": "[email protected]",
        "message_linelength_limit": 2048,
        "no_local_emailing": "0"
    }
}

Please signup or login to give your own answer.

Click here to cancel reply.