Update "tianon/gosu" Docker Hub image to build via bashbrew instead o…

…f bespoke script

This gives us nice provenance, etc; see https://explore.ggcr.dev/?image=tianon/gosu:1.16

hub/gsl.sh

@@ -0,0 +1,54 @@
+#!/usr/bin/env bash
+set -Eeuo pipefail
+
+preferredOrder=( alpine debian )
+
+dir="$(dirname "$BASH_SOURCE")"
+cd "$dir"
+
+commit="$(git log -1 --format='format:%H' HEAD -- .)"
+cat <<-EOH
+ Maintainers: Tianon Gravi <[email protected]> (@tianon)
+ GitRepo: https://github.com/tianon/gosu.git
+ GitCommit: $commit
+ Directory: hub
+ Builder: buildkit
+EOH
+
+version=
+i=0; jq=; froms=()
+for variant in "${preferredOrder[@]}"; do
+ from="$(awk 'toupper($1) == "FROM" { print $2; exit }' "Dockerfile.$variant")" # TODO multi-stage?
+ variantVersion="$(awk 'toupper($1) == "ENV" && toupper($2) == "GOSU_VERSION" { print $3; exit }' "Dockerfile.$variant")"
+ version="${version:-$variantVersion}"
+ if [ "$version" != "$variantVersion" ]; then
+ echo >&2 "error: mismatched version in '$variant' ('$version' vs '$variantVersion')"
+ exit 1
+ fi
+ jq="${jq:+$jq, }$variant: (.[$i].arches | keys_unsorted)"
+ froms["$i"]="$from"
+ (( i++ )) || :
+done
+arches="$(bashbrew remote arches --json "${froms[@]}" | jq -sc "{ $jq }")" # { alpine: [ "amd64", ... ], debian: [ "amd64", ... ] }
+
+queue="$(jq <<<"$arches" -r 'to_entries | map(@sh "variant=\(.key)\narch=\(.value[])") | map(@sh) | join("\n")')"
+eval "queue=( $queue )"
+
+declare -A seenArches=()
+for item in "${queue[@]}"; do
+ eval "$item" # variant=yyy arch=xxx
+ [ -n "$variant" ]
+ [ -n "$arch" ]
+ tags="$variant-$arch"
+ sharedTags="$variant, $version-$variant"
+ if [ -z "${seenArches["$arch"]:-}" ]; then
+ tags+=", $arch"
+ sharedTags+=", $version, latest"
+ fi
+ echo
+ echo "Tags: $tags"
+ [ -z "$sharedTags" ] || echo "SharedTags: $sharedTags"
+ echo "Architectures: $arch"
+ echo "File: Dockerfile.$variant"
+ : "${seenArches["$arch"]:=1}"
+done