docker-coredns/Dockerfile

FROM docker.io/alpine:3.8
LABEL maintainer="Jan Christian Grünhage <jan.christian@gruenhage.xyz"

ARG COREDNS_VERSION=1.2.2

ENV UID=1337 \
    GID=1337

RUN apk add --no-cache \
      s6 \
      su-exec \
      unbound-libs \
      ca-certificates \
      libcap \
      bind-tools \
 && apk add --no-cache \
      -t .build-deps \
      unbound-dev \
      build-base \
      go \
      tar \
      coreutils \
      git \
 && export GOPATH=/tmp/gopath \
 && mkdir -p ${GOPATH}/src/github.com/coredns \
 && cd ${GOPATH}/src/github.com/coredns \
 && wget https://github.com/coredns/coredns/archive/v${COREDNS_VERSION}.tar.gz \
 && tar xf v${COREDNS_VERSION}.tar.gz \
 && mv coredns-${COREDNS_VERSION} coredns \
 && cd coredns \
 && echo "unbound:github.com/coredns/unbound" >> plugin.cfg \
 && go get -d github.com/coredns/unbound \
 && make CHECKS= godeps gen \
 && go build \
 && install -o root -g root -m +x ./coredns /usr/local/bin/coredns \
 && setcap cap_net_bind_service=+ep /usr/local/bin/coredns \
 && cd / \
 && apk del .build-deps \
 && rm -rf /tmp/gopath /root/.cache/go-build

COPY docker/root /

CMD ["/bin/s6-svscan", "/etc/s6.d"]