Add multi-package Alpine packaging

packaging/alpine/blueprint/APKBUILD

@@ -0,0 +1,28 @@
+# Maintainer: Your Name <you@example.com>
+pkgname=example-package
+pkgver=0.1.0
+pkgrel=0
+pkgdesc="Short package description"
+url="https://example.com/example-package"
+arch="x86_64 aarch64"
+license="Apache-2.0"
+depends=""
+makedepends="build-base"
+subpackages="$pkgname-doc"
+source="$pkgname-$pkgver.tar.gz::https://example.com/releases/$pkgver.tar.gz"
+builddir="$srcdir/$pkgname-$pkgver"
+
+build() {
+	make
+}
+
+check() {
+	make check
+}
+
+package() {
+	install -Dm755 "$builddir"/example-package "$pkgdir"/usr/bin/example-package
+}
+
+sha512sums="
+"

packaging/alpine/blueprint/README.md

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+# Alpine Package Blueprint
+
+Copy this directory to `packaging/alpine/local/<pkgname>/` and replace the
+placeholder values before building.
+
+Required:
+
+- `APKBUILD`
+
+Optional package-local hooks:
+
+- `scripts/test-install.sh` validates README-style installation instructions.
+- `scripts/update-generated-sources.sh` refreshes generated files that are
+  listed in `source=`.
+
+Repo-level tasks discover packages from `packaging/alpine/local/*/APKBUILD`.
+Limit a task to one or more packages with:
+
+```sh
+ALPINE_PACKAGE=<pkgname> mise run apk:build
+ALPINE_PACKAGES="<pkg-a> <pkg-b>" mise run apk:build-all
+ALPINE_PACKAGE=<pkgname> mise run apk:test-install
+```
+
+For compiled software, put normal Alpine build logic in `build()`, `check()`,
+and `package()` and declare build tools in `makedepends`.

packaging/alpine/blueprint/scripts/test-install.sh

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+#!/usr/bin/env bash
+set -euo pipefail
+
+repo_root="${REPO_ROOT:-$(cd "$(dirname "${BASH_SOURCE[0]}")/../../../../.." && pwd)}"
+package_name="${PACKAGE_NAME:-$(basename "$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)")}"
+alpine_version="${ALPINE_VERSION:-3.23}"
+arch="${ALPINE_ARCH:-x86_64}"
+
+case "${arch}" in
+  x86_64)
+    platform="${ALPINE_TEST_PLATFORM:-linux/amd64}"
+    ;;
+  aarch64)
+    platform="${ALPINE_TEST_PLATFORM:-linux/arm64}"
+    ;;
+  *)
+    printf 'unsupported Alpine architecture: %s\n' "${arch}" >&2
+    exit 2
+    ;;
+esac
+
+if [[ "${SKIP_BUILD:-0}" != "1" ]]; then
+  ALPINE_PACKAGE="${package_name}" "${repo_root}/scripts/apk/build.sh" build "${arch}"
+fi
+
+docker run --rm --platform "${platform}" \
+  -e "ALPINE_ARCH=${arch}" \
+  -e "PACKAGE_NAME=${package_name}" \
+  -v "${repo_root}/packages/local:/repo:ro" \
+  "alpine:${alpine_version}" \
+  sh -lc '
+    set -e
+
+    cp "/repo/${ALPINE_ARCH}"/*.rsa.pub /etc/apk/keys/
+    printf "%s\n" /repo >> /etc/apk/repositories
+    apk update
+    apk add "${PACKAGE_NAME}"
+
+    # Replace these with package-specific install assertions.
+    apk info -e "${PACKAGE_NAME}"
+  '

packaging/alpine/blueprint/scripts/update-generated-sources.sh

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+#!/usr/bin/env bash
+set -euo pipefail
+
+package_dir="${PACKAGE_DIR:-$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)}"
+
+printf 'No generated sources for %s\n' "${package_dir}"