Ansible Read JSON File: lookup file Plugin & from_json (Guide) — Video Tutorial

How to Read a JSON file into a variable on the host with Ansible? The JSON (JavaScript Object Notation) is an open standard file format used a lot for data interchange. I'm going to show you a live Playbook with some simple Ansible code. I'm Luca Berton, and welcome to today's episode of Ansible Pilot. Ansible reads a JSON file into a variable - `ansible.builtin.file` - read file contents - `from_json filter` - converts the variable to JSON. Let's dive deep into the Ansible lookup plugin file. Plugins are a way to expand the Ansible functionality. With lookup plugins specifically, you can load variables or templates with information from external sources. The full name is `ansible.builtin.file`; it's part of `ansible-core` and is included in all Ansible installations. The purpose of the `file` lookup plugin is to read file contents. The "from_json" is an Ansible-specific filter to convert the input to JSON. Let's combine the result of the `file` lookup plugin with the `from_json` filter for our use case. Playbook How to read the example.json JSON file, assign it to a variable and use it in your Ansible Playbook code. code - example.json ```json { "name": "John", "age": 30 } ``` - read_json.yml ```yaml --- - name: json read Playbook hosts: localhost vars: jsondata: "{{ lookup('file', 'example.json') | from_json }}" tasks: - name: Print variable ansible.builtin.debug: var: jsondata ``` execution ```bash $ ansible-playbook read_json.yml [WARNING]: No inventory was parsed, only implicit localhost is available [WARNING]: provided hosts list is empty, only localhost is available. Note that the implicit localhost does not match 'all' PLAY [json read Playbook] ******************************************************************* TASK [Gathering Facts] ****************************************************************** ok: [localhost] TASK [Print variable] ******************************************************************* ok: [localhost] => { "jsondata": { "age": 30, "name": "John" } } PLAY RECAP ****************************************************************************** localhost : ok=2 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0 ``` idempotency ```bash $ ansible-playbook read_json.yml [WARNING]: No inventory was parsed, only implicit localhost is available [WARNING]: provided hosts list is empty, only localhost is available. Note that the implicit localhost does not match 'all' PLAY [json read Playbook] ******************************************************************* TASK [Gathering Facts] ****************************************************************** ok: [localhost] TASK [Print variable] ******************************************************************* ok: [localhost] => { "jsondata": { "age": 30, "name": "John" } } PLAY RECAP ******************************************************************