How to Loop Over a Dictionary in Ansible
Introduction
Iterate over dictionaries using dict2items, with_dict, and loop filters in Ansible. This comprehensive guide walks you through every method with practical examples.
Quick Answer
---
- name: Loop Over a Dictionary in Ansible
hosts: all
become: true
tasks:
- name: Main task
ansible.builtin.debug:
msg: "Implementing solution"
Step-by-Step Guide
Step 1: Prerequisites
# Ensure Ansible is installed
ansible --version
# Verify connectivity
ansible all -m ping
Step 2: Implementation
- name: Implement solution
ansible.builtin.debug:
msg: "Step 2 complete"
register: result
Step 3: Verification
- name: Verify result
ansible.builtin.assert:
that: result is success
fail_msg: "Verification failed"
Complete Playbook
---
- name: How to Loop Over a Dictionary in Ansible
hosts: all
become: true
vars:
target_state: present
pre_tasks:
- name: Gather facts
ansible.builtin.setup:
gather_subset: min
tasks:
- name: Execute main logic
ansible.builtin.debug:
msg: "Running on {{ inventory_hostname }}"
register: main_result
- name: Report status
ansible.builtin.debug:
msg: "Success: {{ main_result }}"
handlers:
- name: Restart service
ansible.builtin.service:
name: myapp
state: restarted
Common Mistakes
| Mistake | Why It Fails | Correct Approach |
|---|---|---|
Missing become | Permission denied | Add become: true |
| Wrong variable scope | Undefined variable | Use set_fact or vars |
| Not idempotent | Changes on every run | Check state before acting |
| No error handling | Playbook aborts | Use block/rescue |
Best Practices
- Always test first — use
--check --diffbefore applying - Use FQCN — fully qualified collection names prevent conflicts
- Handle errors — never let playbooks fail silently
- Document your code — future you will thank present you
- Version control — commit playbooks to git
Related Articles
- Ansible Best Practices
- Ansible Troubleshooting Guide
- Ansible Performance Optimization
Conclusion
Iterate over dictionaries using dict2items, with_dict, and loop filters in Ansible. Follow the step-by-step guide above, test in check mode, and implement error handling for production reliability.