Dockerfile

ARG CADDY_BUILDER_VERSION=2
ARG CADDY_VERSION=2

FROM --platform=$BUILDPLATFORM caddy:${CADDY_BUILDER_VERSION}-builder-alpine AS build
WORKDIR /tmp/source
ARG CADDY_VERSION
ARG TARGETARCH
RUN --mount=type=bind,target=/tmp/source \
    --mount=type=cache,target=/go/pkg/mod,sharing=locked \
    --mount=type=tmpfs,target=/root/.cache/go-build \
<<EOT
  export GOOS=linux
  export GOARCH=${TARGETARCH}
  xcaddy build v${CADDY_VERSION} \
    --output /usr/bin/caddy-${GOOS}-${GOARCH} \
    $(xargs -a "./modules.txt" -I {} echo --with {}) \
    $(test -f "./replace.txt" && xargs -a "./replace.txt" -I {} echo --replace {})
EOT

FROM caddy:${CADDY_VERSION}-alpine
RUN apk add -Uu --no-cache ca-certificates
ARG TARGETARCH
COPY --link --from=build /usr/bin/caddy-linux-${TARGETARCH} /usr/bin/caddy
RUN caddy list-modules