ansible-playbooks/roles/nginx/README.md
2025-12-15 22:14:46 +01:00

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# Nginx Role
Installs and configures Nginx as a reverse proxy for web applications with modular vhost management.
## Features
- Modular vhost configuration via `/etc/nginx/conf.d/`
- Zero-downtime reloads
- Configurable logging backend (journald or traditional files)
- Automatic logrotate for file-based logging
- SSL/TLS configuration
- **Native ACME/Let's Encrypt support** (Nginx 1.25.0+)
- **Transparent proxy forwarding** (HTTP/HTTPS to other hosts)
## Service Integration Pattern
Each service role should deploy its own vhost config:
**In service role tasks:**
```yaml
- name: Deploy nginx vhost
ansible.builtin.template:
src: nginx-vhost.conf.j2
dest: /etc/nginx/conf.d/myservice.conf
validate: nginx -t
when: myservice_nginx_enabled
notify: Reload nginx
- name: Remove nginx vhost when disabled
ansible.builtin.file:
path: /etc/nginx/conf.d/myservice.conf
state: absent
when: not myservice_nginx_enabled
notify: Reload nginx
```
## Transparent Proxy Forwarding
Forward TCP traffic from this Nginx instance to services on other hosts using the `stream` module (layer 4 proxy).
**Configuration:**
```yaml
nginx_forwarder:
"blog.hello.com":
forward_to: "my.host.lan"
http: true # Forward port 80 (default: true)
https: true # Forward port 443 (default: true)
```
**How it works:**
- **Stream-based TCP proxy** (layer 4, not HTTP layer 7)
- No protocol inspection - just forwards raw TCP packets
- **HTTPS passes through encrypted** - backend host handles TLS termination
- HTTP also uses stream (simpler, but no HTTP features like headers/logging)
**Use case:** Omega (gateway) forwards all traffic to Andromeda (internal server) that handles its own TLS certificates.
**Important notes:**
- Stream configs deployed to `/etc/nginx/streams.d/`
- No HTTP logging (stream doesn't understand HTTP protocol)
- No X-Forwarded-For headers (transparent TCP forwarding)
- Only ONE domain can use port 443 forwarding (TCP port limitation)
## Logging Backends
**journald (default):**
- Logs sent to systemd journal via syslog
- View: `journalctl -u nginx -f`
**file:**
- Traditional `/var/log/nginx/*.log` files
- Automatic logrotate configuration
Switch via `nginx_log_backend` variable.
## Hands-on Commands
```bash
# Test configuration
nginx -t
# Reload (zero downtime)
systemctl reload nginx
# View logs (journald)
journalctl -u nginx -f
journalctl -u nginx -n 100
journalctl -u nginx -p err
# View logs (file)
tail -f /var/log/nginx/access.log
tail -f /var/log/nginx/error.log
# List loaded vhosts
ls -la /etc/nginx/conf.d/
# List stream forwarders
ls -la /etc/nginx/streams.d/
```
## Configuration Variables
See [defaults/main.yml](defaults/main.yml) for all available variables.
## References
- [Nginx Documentation](https://nginx.org/en/docs/)
- [Nginx ACME Support](https://blog.nginx.org/blog/native-support-for-acme-protocol)
- [Nginx Stream Module](https://nginx.org/en/docs/stream/ngx_stream_core_module.html)
- [Nginx Logging](https://nginx.org/en/docs/syslog.html)
- [Nginx SSL/TLS](https://nginx.org/en/docs/http/configuring_https_servers.html)