Docker's custom iptables chains, upon restart of network or docker, can and most likely WILL clobber rules that used to work. Docker adds the DOCKER-USER user c

Docker's custom iptables chains, upon restart of network or docker, can and most likely WILL clobber rules that used to work. Docker adds the DOCKER-USER user chain for the purpose of readding rules back after docker has set up its rules. Most engineers never have to deal with it unless they are deploying to production boxes.