anchor.diff:    # Needed for running gollum
     && apk --update add git=$GIT_VERSION \
     # Needed for setcap
  -  libcap=2.26-r0 \
  +  libcap=$LIBCAP_VERSION \
     # cleanup apk cache
     && rm -rf /var/cache/apk/* \
     # Initialize wiki data.
  
positive.code: ARG GIT_TAG
  ARG BUILD_DATE
  # - Sources:
  #   - https://pkgs.alpinelinux.org/packages?name=git&branch=v3.9
  ARG GIT_VERSION=2.20.1-r0
  
  # See https://github.com/opencontainers/image-spec/blob/master/annotations.md
  LABEL org.opencontainers.image.created="${BUILD_DATE}" \
  
negative.code: # Build caddy from source, because binaries are published under a commercial license: https://caddyserver.com/pricing
  # Starting with 1.0.0 we seem to no longer have to do this:  https://github.com/mholt/caddy/releases/tag/v1.0.0
  # OTOH - with explicit plugin versions the build remains more deterministic than downloading the "latest" plugins via https://caddyserver.com/download
  FROM golang:1.12.8 as caddybuild
  
  # https://github.com/mholt/caddy/releases
  ARG CADDY_VERSION="v1.0.3"
  