I am very new to using docker. I have been used to using dedicated VM’s and hosting the applications within the servers OS.

When hosting multiple applications/services that require the same port, is it best practice to spin up a whole new docker server or how should I go about the conflicts?

Ie. Hosting multiple web applications that utilize 443.

Thank you!

  • @[email protected]OP
    link
    fedilink
    English
    111 year ago

    Thank you! I am using Caddy and was able to define a unique random port for the other containers and access this via reverse proxy!

    • @herrfrutti
      link
      English
      61 year ago

      If the containers are all in the same network. You dont need to expose a port.

      Lets assume you create a docker network called reverse_proxy and add all your contaiers that you want to be accessed by the reverse proxy to that network (including caddy).

      Then you can address all containers through the hostname in you caddy file and the port would be the default configurated port from the container.

      So in the end you just expose the caddy container and nothing more.

      • @damo_omad
        link
        English
        31 year ago

        I didn’t know this, very handy thanks

      • @[email protected]
        link
        fedilink
        English
        21 year ago

        That wouldn’t work if multiple containers use the same port (eg. 8000), right?

        Without a docker network, I can just map 8001:8000 and don’t have that issue.

        • @[email protected]
          link
          fedilink
          English
          41 year ago

          Yes, it’d work just fine because each container listens on port 8000 of their own IP address, not the docker server’s IP address. Caddy/Traefik just redirects traffic to that port.

            • @herrfrutti
              link
              English
              1
              edit-2
              1 year ago

              I’ve just posted a little example. I’d recommend doing it this way. No more thinking about what port is allready exposed etc

      • @[email protected]OP
        link
        fedilink
        English
        21 year ago

        In addition to Caddy being apart of the reverse_proxy network. Would I also have to add it to the Bridge network so that I can utilize the machine IP that docker is hosted on for port forwarding 443?

        • @herrfrutti
          link
          English
          51 year ago

          Caddy would have the bridge proxy network and the port 443 exposed.

          version: "3.7"
          
          networks:
            proxy-network:
              external: true
          # needs to be created manually bevor running (docker create network proxy-network)
          services:
            caddy:
              image: caddy
              container_name: caddy
              restart: unless-stopped
              ports:
                - 80:80
                - 443:443
              volumes:
                - ./data:/data
                - ./config:/config
                - ./Caddyfile:/etc/caddy/Caddyfile:ro
              networks:
                - proxy-network
          

          Other services:

          version: "3.7"
          
          networks:
            proxy-network:
              external: true
          
          services:
            app:
              image: app
              container_name: app
              restart: unless-stopped
              volumes:
                - ./app-data:/data
              networks:
                - proxy-network
          

          Caddy can now talk to the app with the apps container_name.

          Caddyfile:

          homepage.domain.de {
              reverse_proxy app:80
          }
          

          So the reverse proxy network is an extra network only for containers that need to be exposed.