FROM golang:1-alpine AS build
WORKDIR /src
COPY go.mod go.sum ./
RUN go mod download
COPY . .
ARG VERSION=dev
RUN CGO_ENABLED=0 go build -trimpath -ldflags "-s -w -X main.version=${VERSION}" -o /out/canon ./cmd/canon

FROM alpine:3
RUN apk add --no-cache ca-certificates tzdata su-exec \
 && mkdir -p /data /backups
COPY --from=build /out/canon /usr/local/bin/canon
COPY docker-entrypoint.sh /usr/local/bin/docker-entrypoint.sh
RUN chmod 755 /usr/local/bin/docker-entrypoint.sh
# The entrypoint starts as root only to set ownership, then runs Canon as
# PUID:PGID.
ENV CANON_DATA_DIR=/data \
    CANON_PORT=4242 \
    PUID=1000 \
    PGID=1000 \
    UMASK=022
VOLUME /data /backups
EXPOSE 4242
HEALTHCHECK --interval=30s --timeout=3s --start-period=5s \
  CMD wget -qO- http://127.0.0.1:${CANON_PORT}/healthz >/dev/null || exit 1
ENTRYPOINT ["docker-entrypoint.sh"]