Docker network IP allocation issue

General Discussions
1

Hello,

I am running 2 docker container one is apache (webserver) and other is MySQl (dataserver).
I created a network, network details are given below.

            "Name": "dataserver",
            "EndpointID": "d3f070376cb77a2b0d61b21b2b8ba6f72e60f127d3e09a14f07acab199316110",
            "MacAddress": "02:42:ac:12:00:03",
            "IPv4Address": "172.18.0.3/16",
            "IPv6Address": ""
        },
        "dd66c6cfb221d715141be2df2bb7dd0a94224d741b811670867a2112fd576c58": {
            "Name": "webserver",
            "EndpointID": "de664313d5e6b4bdfc2692f8c700da09f8ba34582d4f51004cf48d1568de2032",
            "MacAddress": "02:42:ac:12:00:02",
            "IPv4Address": "172.18.0.2/16",
            "IPv6Address": ""

Here, I am using host 172.18.0.3 to connect to DB from the webserver. But when I restart the container the IP allocate to them is interchanged, due to this I cannot connect to the DB server from webserver.
Do I need to change each time my web server configuration to connect to DB or any other method is available?

2

You should to configure your Web server container to use the container name of the database container as a DNS name (that is, set something like MYSQL_HOST=dataserver). Docker provides an internal DNS service that will resolve it to the correct place. You should never be looking at these IP addresses (as you note they change routinely).