I use the drone-docker plugin to build images and it’s been working fine for a while. I had not made commits that prompted builds for a few weeks, but now the process errs due to the docker build process within drone-docker not being able to pull images. I exec’d into the step during its execution and saw something interesting. There is the expected docker0 bridge within the container (172.18.0.1), as well as eth0 (172.18.0.2), and eth1 (172.17.0.2). It is eth1 that bridges to the host’s docker0 bridge. Doing an “ip route show” confirms that the default route for the container is to 172.18.0.1, which is the container’s docker0 bridge. Is this correct behavior? If I manually remove the default route and force it to be via the host’s bridge, then I can start accessing routable IP space and the build starts to proceed further. I cannot verify for previous builds, but I feel like the container is getting created and the interfaces are being enumerated differently now which is causing the routing confusion
The only difference I can tell between a few weeks ago and now is that I am on a slighter newer kernel. I was using 4.4.0-112-generic, now I am on 4.4.0-116-generic on the host.
Thanks for any help!