content: # syntax=docker/dockerfile:1
  
  ARG GO_VERSION="1.23"
  ARG ALPINE_VERSION="3.21"
  ARG GOMOD_OUTDATED_VERSION="v0.8.0"
  
  FROM golang:${GO_VERSION}-alpine${ALPINE_VERSION} AS base
  ENV GOFLAGS="-mod=vendor"
  RUN apk add --no-cache git linux-headers musl-dev rsync
  WORKDIR /src
  
  FROM base AS vendored
  RUN --mount=target=/context \
      --mount=target=.,type=tmpfs  \
      --mount=target=/go/pkg/mod,type=cache <<EOT
    set -e
    rsync -a /context/. .
    go mod tidy
    go mod vendor
    mkdir /out
    cp -r go.mod go.sum vendor /out
  EOT
  
  FROM scratch AS update
  COPY --from=vendored /out /
  
  FROM vendored AS validate
  RUN --mount=target=/context \
      --mount=target=.,type=tmpfs <<EOT
    set -e
    rsync -a /context/. .
    git add -A
    rm -rf vendor
    cp -rf /out/* .
    if [ -n "$(git status --porcelain -- go.mod go.sum vendor)" ]; then
      echo >&2 'ERROR: Vendor result differs. Please vendor your package with "make vendor"'
      git status --porcelain -- go.mod go.sum vendor
      exit 1
    fi
  EOT
  
  FROM psampaz/go-mod-outdated:${GOMOD_OUTDATED_VERSION} AS go-mod-outdated
  FROM base AS outdated
  RUN --mount=type=bind,target=.,rw \
      --mount=type=cache,target=/go/pkg/mod \
      --mount=from=go-mod-outdated,source=/home/go-mod-outdated,target=/usr/bin/go-mod-outdated \
      go list -mod=mod -u -m -json all | go-mod-outdated -update -direct
  