Docker - Incorrect DNS address being sent to DHCP clients

asepion · June 15, 2020, 1:26am

Looking through more issues, this seems like it might be relevant:

PiHole DHCP has wrong dhcp-option=option:dns-server

opened 12:29PM - 27 Feb 19 UTC

bug

I'm running docker.io/pihole/pihole:4.2.2_armhf. Devices using dhcp receive the… container's IP address and the DNS host. I am not using --net=host. A working config is described here: http://www.electricbrain.com.au/pages/desktop-datacenter-software/pi-hole-docker.php This is a... - [X] Request for a new or modified feature - [ ] Issue trying to run the docker image - [ ] Issue trying to build / test / develop the docker image ## Description The web interface needs to include an option to use the host's IP address for DHCP option dns-server. ## Expected Behavior DHCP Clients should get the host's address returned for DNS server (not the container's) ## Actual Behavior All requests receive the container's IP address (which can be the hosts if --net=host is used). ## Possible Fix Work-around is to add entry to 02-pihole-dhcp.conf and then use: chattr +i 02-pihole-dhcp.conf to prevent the web interface from making changes. ## Steps to Reproduce and debugging done e.g. your docker run command, pages to visit, CLI commands you ran 1. Start container without --net-host. 2. From client check resolv.conf for the DNS server's ip address 3. 4. ## Debug steps I have tried - [ ] I have tried destroying my container instance, pulling the newest image version, and re-creating a new container - [ ] I have tried running the nearly stock `docker run` example in the readme (removing any customizations I added) - [ ] I have tried running without my volume data mounts to eliminate volumes as the cause - [ ] I have searched this repository for existing issues and pull requests that look similar ## Context and extra information PiHole container is running fine with the workaround. It uses standard networking now and does not require --net=host. It might even work with zero additional privileges. Note: dhcrelay is essential. ## Your Environment * Docker Host Operating System and OS Version: * Docker Version: * Hardware architecture: