Use jq-template.awk

.gitattributes

@@ -0,0 +1,3 @@
+**/Dockerfile        linguist-generated
+**/start-qemu        linguist-generated
+Dockerfile.template  linguist-language=Dockerfile

.github/workflows/verify-templating.yml

@@ -0,0 +1,22 @@
+name: Verify Templating
+
+on:
+  pull_request:
+  push:
+
+defaults:
+  run:
+    shell: 'bash -Eeuo pipefail -x {0}'
+
+jobs:
+  apply-templates:
+    name: Check For Uncomitted Changes
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Apply Templates
+        run: ./apply-templates.sh
+      - name: Check Git Status
+        run: |
+          status="$(git status --short)"
+          [ -z "$status" ]

.gitignore

@@ -0,0 +1 @@
+.jq-template.awk

Dockerfile.template

@@ -14,8 +14,8 @@ ENV QEMU_KEYS \
 
 # https://www.qemu.org/download/#source
 # https://download.qemu.org/?C=M;O=D
-ENV QEMU_VERSION %%QEMU_VERSION%%
-ENV QEMU_URL %%QEMU_URL%%
+ENV QEMU_VERSION {{ .version }}
+ENV QEMU_URL {{ .url }}
 
 RUN set -eux; \
 	\

apply-templates.sh

@@ -0,0 +1,40 @@
+#!/usr/bin/env bash
+set -Eeuo pipefail
+
+[ -f versions.json ] # run "versions.sh" first
+
+jqt='.jq-template.awk'
+if [ -n "${BASHBREW_SCRIPTS:-}" ]; then
+	jqt="$BASHBREW_SCRIPTS/jq-template.awk"
+elif [ "$BASH_SOURCE" -nt "$jqt" ]; then
+	wget -qO "$jqt" 'https://github.com/docker-library/bashbrew/raw/5f0c26381fb7cc78b2d217d58007800bdcfbcfa1/scripts/jq-template.awk'
+fi
+
+if [ "$#" -eq 0 ]; then
+	versions="$(jq -r 'keys | map(@sh) | join(" ")' versions.json)"
+	eval "set -- $versions"
+fi
+
+generated_warning() {
+	cat <<-EOH
+		#
+		# NOTE: THIS DOCKERFILE IS GENERATED VIA "apply-templates.sh"
+		#
+		# PLEASE DO NOT EDIT IT DIRECTLY.
+		#
+
+	EOH
+}
+
+for version; do
+	export version
+
+	echo "processing $version ..."
+
+	{
+		generated_warning
+		gawk -f "$jqt" Dockerfile.template
+	} > "$version/Dockerfile"
+
+	cp -a start-qemu "$version/"
+done

generate-stackbrew-library.sh

@@ -10,8 +10,10 @@ declare -A aliases=(
 self="$(basename "$BASH_SOURCE")"
 cd "$(dirname "$(readlink -f "$BASH_SOURCE")")"
 
-versions=( */ )
-versions=( "${versions[@]%/}" )
+if [ "$#" -eq 0 ]; then
+	versions="$(jq -r 'keys | map(@sh) | join(" ")' versions.json)"
+	eval "set -- $versions"
+fi
 
 # sort version numbers with highest first
 IFS=$'\n'; versions=( $(echo "${versions[*]}" | sort -rV) ); unset IFS
@@ -52,10 +54,8 @@ join() {
 	echo "${out#$sep}"
 }
 
-for version in "${versions[@]}"; do
-	commit="$(dirCommit "$version")"
-
-	fullVersion="$(git show "$commit":"$version/Dockerfile" | awk '$1 == "ENV" && $2 == "QEMU_VERSION" { print $3; exit }')"
+for version; do
+	fullVersion="$(jq -r --arg version "$version" '.[$version].version' versions.json)"
 
 	rcVersion="${version%-rc}"
 
@@ -69,6 +69,8 @@ for version in "${versions[@]}"; do
 		${aliases[$version]:-}
 	)
 
+	commit="$(dirCommit "$version")"
+
 	echo
 	cat <<-EOE
 		Tags: $(join ', ' "${versionAliases[@]}")

update.sh

@@ -3,46 +3,5 @@ set -Eeuo pipefail
 
 cd "$(dirname "$(readlink -f "$BASH_SOURCE")")"
 
-versions=( */ )
-versions=( "${versions[@]%/}" )
-
-# https://download.qemu.org/?C=M;O=D
-urls="$(
-	wget -qO- 'https://www.qemu.org/download/' \
-		| grep -oE 'https://download[.]qemu[.]org/qemu-([^"]+)[.]tar[.]xz' \
-		| sort -ruV
-)"
-
-for version in "${versions[@]}"; do
-	rcGrepV='-v'
-	rcVersion="${version%-rc}"
-	if [ "$rcVersion" != "$version" ]; then
-		rcGrepV=
-	fi
-
-	url="$(
-		grep -E "qemu-$rcVersion([.-])" <<<"$urls" \
-			| grep $rcGrepV -E -- '-rc' \
-			| head -1
-	)"
-	fullVersion="${url##*/qemu-}"
-	fullVersion="${fullVersion%%.tar.*}"
-
-	echo "$version: $fullVersion"
-
-	sed -r \
-		-e 's/%%QEMU_VERSION%%/'"$fullVersion"'/g' \
-		-e 's!%%QEMU_URL%%!'"$url"'!g' \
-		Dockerfile.template > "$version/Dockerfile"
-	cp -a start-qemu "$version/"
-
-	case "$rcVersion" in
-		# https://github.com/qemu/qemu/commit/b10d49d7619e4957b4b971f816661b57e5061d71
-		3.0 | 3.1 | 4.0)
-			sed -ri \
-				-e 's/libssh-dev/libssh2-1-dev/g' \
-				-e 's/--enable-libssh/--enable-libssh2/g' \
-				"$version/Dockerfile"
-			;;
-	esac
-done
+./versions.sh "$@"
+./apply-templates.sh "$@"

versions.json

@@ -0,0 +1,18 @@
+{
+  "4.1": {
+    "url": "https://download.qemu.org/qemu-4.1.1.tar.xz",
+    "version": "4.1.1"
+  },
+  "4.2": {
+    "url": "https://download.qemu.org/qemu-4.2.1.tar.xz",
+    "version": "4.2.1"
+  },
+  "5.0": {
+    "url": "https://download.qemu.org/qemu-5.0.0.tar.xz",
+    "version": "5.0.0"
+  },
+  "5.1": {
+    "url": "https://download.qemu.org/qemu-5.1.0.tar.xz",
+    "version": "5.1.0"
+  }
+}

versions.sh

@@ -0,0 +1,48 @@
+#!/usr/bin/env bash
+set -Eeuo pipefail
+
+cd "$(dirname "$(readlink -f "$BASH_SOURCE")")"
+
+versions=( "$@" )
+if [ ${#versions[@]} -eq 0 ]; then
+	versions=( */ )
+	json='{}'
+else
+	json="$(< versions.json)"
+fi
+versions=( "${versions[@]%/}" )
+
+# https://download.qemu.org/?C=M;O=D
+urls="$(
+	wget -qO- 'https://www.qemu.org/download/' \
+		| grep -oE 'https://download[.]qemu[.]org/qemu-([^"]+)[.]tar[.]xz' \
+		| sort -ruV
+)"
+
+for version in "${versions[@]}"; do
+	rcGrepV='-v'
+	rcVersion="${version%-rc}"
+	if [ "$rcVersion" != "$version" ]; then
+		rcGrepV=
+	fi
+
+	url="$(
+		grep -E "qemu-$rcVersion([.-])" <<<"$urls" \
+			| grep $rcGrepV -E -- '-rc' \
+			| head -1
+	)"
+	fullVersion="${url##*/qemu-}"
+	fullVersion="${fullVersion%%.tar.*}"
+
+	echo "$version: $fullVersion"
+
+	export version fullVersion url
+	json="$(jq <<<"$json" '
+		.[env.version] = {
+			version: env.fullVersion,
+			url: env.url,
+		}
+	')"
+done
+
+jq <<<"$json" -S . > versions.json