# Global build argument
ARG THTTPD_VER=2.29
ARG DI_VER=1.2.5

FROM alpine:3 AS builder


# =====BUILD BINARIES=====
WORKDIR /usr/src
ARG THTTPD_VER
ARG DI_VER

# Install build dependencies
# bash: required for dumb-init's Makefile
# clang, build-base: compilation (I just like clang)
# curl: downloading the tarballs
# hugo: generating the static files
RUN apk add --update --no-cache \
    bash \
    build-base \
    clang \
    curl \
    hugo \
    musl-dev

# Build thttpd
RUN curl -sSL "https://www.acme.com/software/thttpd/thttpd-$THTTPD_VER.tar.gz" | \
        tar xzf - && \
    cd "thttpd-$THTTPD_VER" && \
    CC=clang ./configure && \
    make CCOPT="-O3 -s -static" -j$(nproc)

# Build dumb-init
# dumb-init's Makefile already specifies static build flags, so we don't have to specify them
RUN curl -sSL "https://github.com/Yelp/dumb-init/archive/refs/tags/v$DI_VER.tar.gz" | \
    tar xzf - && \
    cd "dumb-init-$DI_VER" && \
    CC=clang make build


# =====BUILD BLOG=====
WORKDIR /usr/src/app

# Copy site files for building
COPY . ./

# Generate the site
# The find command fixes file permissions, because thttpd thinks executables should be CGI files
RUN hugo --minify && \
    find public -type f -exec chmod 644 {} \;


# ====CREATE RELEASE IMAGE====
FROM scratch
ARG THTTPD_VER
ARG DI_VER

# Copy over binary & static files
COPY --from=builder /usr/src/thttpd-$THTTPD_VER/thttpd /bin/thttpd
COPY --from=builder /usr/src/dumb-init-$DI_VER/dumb-init /bin/dumb-init
COPY --from=builder /usr/src/app/public /static

# A static file server doesn't need root
USER 82:82

ENTRYPOINT [ "/bin/dumb-init", "--" ]
CMD [ "/bin/thttpd", "-D", "-d", "/static", "-p", "8080" ]