Network Services Automation

You will deploy and manage DNS and DHCP from code with Ansible, generating zone and scope files from templates. By the end network services are reproducible, version-controlled, and validated on every run.

Learning Objectives

Template DNS zones and DHCP scopes from variables.
Deploy services idempotently with Ansible.
Validate configuration before reloading.
Time: ~12 hours · Difficulty: Advanced · Prereqs: the DNS, DHCP, and automation labs.

Architecture Overview

graph LR Vars[group_vars] --> Tpl[Jinja2 templates] Tpl --> Ans[Ansible] Ans -->|deploy + validate| DNS[BIND9] Ans -->|deploy + validate| DHCP[ISC DHCP]

Environment Setup

Ansible control node with SSH to service hosts.
BIND9 and ISC DHCP target hosts.
Variables describing zones, records, and scopes.

Step-by-Step Execution

Template the zone and scope files

ansible-playbook -i inventory.ini dns-dhcp.yml --check --diff

Previews the rendered config before applying.

Validate before reload

The playbook runs named-checkzone and dhcpd -t before reloading, so a bad template never takes a service down.

ansible-playbook -i inventory.ini dns-dhcp.yml

Confirm idempotency

$ ansible-playbook -i inventory.ini dns-dhcp.yml

PLAY RECAP ns1: ok=9 changed=0 dhcp1: ok=7 changed=0

Progress So Far

graph LR A[01 Template] -->|done| B[02 Validate + deploy] B -->|done| C[03 Idempotent] style A fill:#1a4a1a,stroke:#00ff00,color:#fff style B fill:#1a4a1a,stroke:#00ff00,color:#fff style C fill:#1a4a1a,stroke:#00ff00,color:#fff

Testing & Validation

dig @ns1 web.lab +short && ansible-playbook -i inventory.ini dns-dhcp.yml --check

DNS should resolve and a check run should report no changes. If so, your network services are fully codified and idempotent.

Troubleshooting

changed=1 every run: templates produce non-deterministic output; sort and normalize.
Service down after deploy: ensure validation tasks gate the reload handler.
Stale zone: bump the SOA serial in the template on each change.

Extension Ideas

Add device config automation for switches/routers.
Run from CI/CD with approvals.
Combine with Complete Network Implementation.

Key Results

Codified DNS and DHCP from templated variables.
Gated reloads behind config validation.
Achieved idempotent runs (changed=0 on repeat).
Made network services version-controlled and reproducible.

Network Services Automation with Ansible