i have one docker container (let’s call it “whoops”) set with a static ip address (172.16.0.18) to accommodate a specific tunneling application. yesterday, i rebooted my unraid server. i noticed that “whoops” had failed to start up, so i manually started it. the web ui gave me a modal saying:

Execution Error

Error code 403

after about an hour of troubleshooting, i finally realized that another container earlier in the container startup order had been handed 172.16.0.18. this is what had been preventing “whoops” from starting up. i have reassigned “whoops” the address 172.16.0.99, in the hope that no other container starting before it will be given an ip address incremented that high.

however, i think it’s reasonable to assume that when a container is given a static IP address, this would prevent other containers from being given this IP address.

additionally, the error message in the web UI really could be more clear and specific!

Edited January 19Jan 19 by almighty7lurch

This is a docker engine issue and doesn't work quite the same as a normal dhcp service.

The work around is change the docker network dhcp pool so that it excludes a range that you will be assigning static IPs to.

Also note that within a specific docker custom network, other containers IPs in that network are resolvable by container name, so if your tunnelling app is in same network as "whoops", you can use the container name instead of relying on a static IP.