update dockerfile to allow use of https_google - fixes
* update dockerfile to allow use of https_google
to use TLS in a docker container (based on Alpine linux) you need to also include the CA certificate files
* cleaned up version of Dockerfile that supports https_google
FROM alpine:latest
MAINTAINER Miek Gieben <miek@miek.nl> @miekg
-RUN apk --update add bind-tools && rm -rf /var/cache/apk/*
+# only need ca-certificates & openssl if want to use https_google
+RUN apk --update add bind-tools ca-certificates openssl && update-ca-certificates && rm -rf /var/cache/apk/*
ADD coredns /coredns
