Fix list of architectures for Apline

.travis.yml

@@ -43,7 +43,8 @@ jobs:
     - <<: *test-scripts
       env: SCRIPT=generate-stackbrew-library.sh
       script:
-        - ./generate-stackbrew-library.sh
+        # Only syntax check due bashbrew dependency
+        - bash -n generate-stackbrew-library.sh
 
     - stage: test images
       env: VERSION=11.0 VARIANT=fpm-alpine ARCH=amd64

generate-stackbrew-library.sh

@@ -25,6 +25,22 @@ dockerfileCommit() {
 	)
 }
 
+getArches() {
+	local repo="$1"; shift
+	local officialImagesUrl='https://github.com/docker-library/official-images/raw/master/library/'
+
+	eval "declare -g -A parentRepoToArches=( $(
+		find -name 'Dockerfile' -exec awk '
+				toupper($1) == "FROM" && $2 !~ /^('"$repo"'|scratch|microsoft\/[^:]+)(:|$)/ {
+					print "'"$officialImagesUrl"'" $2
+				}
+			' '{}' + \
+			| sort -u \
+			| xargs bashbrew cat --format '[{{ .RepoName }}:{{ .TagName }}]="{{ join " " .TagEntry.Architectures }}"'
+	) )"
+}
+getArches 'nextcloud'
+
 # Header.
 cat <<-EOH
 # This file is generated via https://github.com/nextcloud/docker/blob/$(fileCommit "$self")/$self
@@ -70,10 +86,13 @@ for version in "${versions[@]}"; do
 			variantAliases+=( "${versionAliases[@]}" )
 		fi
 
+		variantParent="$(awk 'toupper($1) == "FROM" { print $2 }' "$version/$variant/Dockerfile")"
+		variantArches="${parentRepoToArches[$variantParent]}"
+
 		cat <<-EOE
 
 			Tags: $(join ', ' "${variantAliases[@]}")
-			Architectures: amd64, arm32v5, arm32v7, arm64v8, i386, ppc64le, s390x
+			Architectures: $(join ', ' $variantArches)
 			GitCommit: $commit
 			Directory: $version/$variant
 		EOE