Caching resolver for docker DNS
DISCLAIMER: this library was initially built for internal use in like 2 hours, so code is pretty bad and stability is REALLY not guaranteed. Some people asked me to put it on github, and so I did.
Full documentation can be found on godoc
Main purpose of the library is to bypass docker's libnetwork limit of 100 concurrent queries to the internal resolver by using very simple cache mechanism. We use it with our init-like supervisor in production, and it seems that for our use cases it works pretty well.
Usage:
package main
func main() {
resolver := dnscache.NewResolver("127.0.0.1", 53)
resolver.Start()
}Especially for user-defined docker networks there's a really shitty workaround for updating resolv.conf. It was made into a separate function because it's only needed with user-defined networks or docker-compose usage (this is what actually made me do that docker/compose#2847). I don't recommend using it 'as is' unless you are really desperate.
dnscache.ReplaceDockerDns(resolver.ListenAddr())