Docker Container/Service with Same Port: Best Practices?
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!
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That's the cool thing about docker you can just map a different external port.
https://docs.docker.com/network/
So if you look at the first flag it mentions: -p 8080:80
This means it's mapping external port 8080 to the internal port 80. You can change the 8080 to anything you want so you don't have conflicts.
I have done what you mentioned and used a random port internally and kept 443 as the listening port. I am using Caddy to then direct the traffic reverse proxy it.
Thank you so much!
Just FYI, we may be using "internally" differently, but you can't change the port number to the right of the ":" That's usually a fixed port needed for the container (the internal docker port).
I think you are using "internal" to mean your local network port though, but in Dockers case it would be the "external port" (external to docker).
Flow would be: Proxy → External Docker Port (8080, can be variable) → Internal Docker Port (80, fixed per docker container)
Probably getting overly picky with wording, but wanted to make sure you knew that the inernal docker port can't be changed, just the mapping.
Thanks for the heads-up on terminology! What you mentioned is how I set it up.
I had no idea that the ports could be configured like that! This is very helpful. Docker is a beast to get used to!