generate-stackbrew-library.sh

#!/usr/bin/env bash
set -Eeuo pipefail

declare -A aliases=(
	[5.7]='5'
	[8.0]='8 latest'
)

self="$(basename "$BASH_SOURCE")"
cd "$(dirname "$(readlink -f "$BASH_SOURCE")")"

if [ "$#" -eq 0 ]; then
	versions="$(jq -r 'keys | map(@sh) | join(" ")' versions.json)"
	eval "set -- $versions"
fi

# sort version numbers with highest first
IFS=$'\n'; set -- $(sort -rV <<<"$*"); unset IFS

# get the most recent commit which modified any of "$@"
fileCommit() {
	git log -1 --format='format:%H' HEAD -- "$@"
}

# get the most recent commit which modified "dir/dockerfile" or any file COPY'd from it
dirCommit() {
	local dir="$1"; shift
	local df="$1"; shift
	(
		cd "$dir"
		local files; files="$(
			git show "HEAD:./$df" | awk '
				toupper($1) == "COPY" {
					for (i = 2; i < NF; i++) {
						print $i
					}
				}
			'
		)"
		fileCommit "$df" $files
	)
}

cat <<-EOH
# this file is generated via https://github.com/docker-library/mysql/blob/$(fileCommit "$self")/$self

Maintainers: Tianon Gravi <admwiggin@gmail.com> (@tianon),
             Joseph Ferguson <yosifkit@gmail.com> (@yosifkit)
GitRepo: https://github.com/docker-library/mysql.git
EOH

# prints "$2$1$3$1...$N"
join() {
	local sep="$1"; shift
	local out; printf -v out "${sep//%/%%}%s" "$@"
	echo "${out#$sep}"
}

for version; do
	export version
	df='Dockerfile.debian'
	commit="$(dirCommit "$version" "$df")"

	fullVersion="$(jq -r '.[env.version].version' versions.json)"

	versionAliases=()
	while [ "$fullVersion" != "$version" -a "${fullVersion%[.-]*}" != "$fullVersion" ]; do
		versionAliases+=( $fullVersion )
		fullVersion="${fullVersion%[.-]*}"
	done
	versionAliases+=(
		$version
		${aliases[$version]:-}
	)

	echo
	cat <<-EOE
		Tags: $(join ', ' "${versionAliases[@]}")
		GitCommit: $commit
		Directory: $version
		File: $df
	EOE
done