Operations
Reverse proxy, mail, migrations and monitoring.
- MX Record Setup for Your Own Mail Server (Postfix)
MX record setup for Postfix on a VPS: MX, A, SPF, DKIM, DMARC and PTR. Zone file, priority values, dig and openssl checks and the four mistakes behind lost mail.
- Reverse DNS PTR Record: Set It at Your Host, Not Registrar
A reverse DNS PTR record maps an IP to a hostname. It is set at your hosting provider, not your registrar. How to check forward-confirmed rDNS for Postfix.
- Reverse Proxy for Multiple Domains: nginx, Caddy, Traefik
Run a reverse proxy for multiple domains on one VPS: one IP, ports 80 and 443, routing by hostname. Working configs for nginx, Caddy and Traefik Docker labels.
- Server Migration Without Downtime: TTL, rsync, Proxy
Server migration without downtime in 7 steps: lower the TTL a day ahead, rsync data and certificates, test with curl --resolve, keep the old server as a proxy.