#!/bin/sh
# script/lint: run the linter. Linting is a phase of the Dockerfile and
# this builds that phase alone; the linter is never installed or run on
# a developer host, where a shared result cache and a host-global lock
# make its answer untrustworthy.
#
# The phase is not the last stage in the file, so it is built only when
# --target names it. A new CACHEBUST value reruns every RUN step, since
# a cached lint layer is a lint that did not run; unlike --no-cache, it
# keeps Go's build cache. This relies on every stage of the Dockerfile
# declaring ARG CACHEBUST first; a stage without that line is served
# from cache on an unchanged tree, with no warning.
# --output type=cacheonly writes no image, since nothing uses one.
set -eu

SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"

main() {
    cd "$ROOT"
    docker build --build-arg CACHEBUST="$(date +%s)-$$" \
        --target lint \
        --output type=cacheonly .
}

main "$@"