Can I run two containers on one small server?
Ports and memory
Two containers can share a host if they listen on different ports, or if a reverse proxy sends traffic to each one. Each container also needs room for memory and CPU, so check usage after both are running. A server that works fine with one app can slow down badly with two heavier ones.
- Give each service a unique host port
- Set memory limits for each container
- Check usage with docker stats
Routing traffic
A reverse proxy such as Nginx or Caddy can accept requests on ports 80 and 443 and forward them to the right container. You can route by domain name or by URL path. This keeps both services reachable without exposing every port to the internet.
Keeping them separate
Put each app on its own Docker network if they should not talk to each other directly. Use separate volumes for data so one app cannot overwrite the other's files. Clear naming in your compose file makes the setup easier to maintain.
Keep a simple diagram of which container listens on which port, so the next person can trace a request without guessing.
Common mistakes
- Mapping two containers to the same host port.
- Skipping memory limits until one app crashes the other.
- Exposing database ports to the public internet by accident.
