I'm kind of new on docker. I want to resolve DNS name into something define by the user. I mean, I have a service in docker which requires another service located in 'myEndpoint'. I want to configure that when the service asked to 'myEndpoint' returns an IP/FQN I decide, either in the containers or outside.
How I can do this?
If you just want to map myEndpoing to a specific IP, you could use option --add-host when docker run ... your container. Take a look at the following example:
~/ docker run --add-host=myEndpoint:123.124.125.126 --rm alpine:3.3 ping myEndpoint -c 4
PING myEndpoint (123.124.125.126): 56 data bytes
64 bytes from 123.124.125.126: seq=0 ttl=37 time=0.522 ms
64 bytes from 123.124.125.126: seq=1 ttl=37 time=0.391 ms
64 bytes from 123.124.125.126: seq=2 ttl=37 time=2.161 ms
64 bytes from 123.124.125.126: seq=3 ttl=37 time=0.488 ms
--- myEndpoint ping statistics ---
4 packets transmitted, 4 packets received, 0% packet loss
round-trip min/avg/max = 0.391/0.890/2.161 ms
You can refer to the docs of docker run for more details.
But if you want to map myEndpoint to other domain name, I think you need to use a FQDN and configure it as a CNAME DNS record, then configure DNS server for your container with option --dns options when you do docker run .... Hope this could be helpful :)