feat: Add multi-architecture Docker image build script and update README

README.md

@@ -1,6 +1,6 @@
 # Cloudflare compatible PowerDNS API Server
 
-[![Discord](https://img.shields.io/discord/630271953806295051)](https://discord.gg/EPnCfz7xx5) [![Build Status](https://teamcity.mori.space/app/rest/builds/buildType:PdnsApi_Build/statusIcon)](https://teamcity.mori.space/project/PdnsApi)
+[![Discord](https://img.shields.io/discord/630271953806295051)](https://discord.gg/EPnCfz7xx5)
 
 A Kotlin and Spring Boot API that exposes Cloudflare-style zone and DNS record endpoints backed by PowerDNS and MariaDB. API requests use `Authorization: Bearer <API_KEY>`.
 
@@ -26,6 +26,23 @@ Use JDK 25. The Gradle wrapper selects the Java 25 toolchain for compilation.
 | `PDNS_API_URL` | PowerDNS HTTP API base URL, for example `http://pdns:8081` |
 | `PDNS_NS` | Comma-separated nameservers, for example `ns1.example.com,ns2.example.com` |
 
+## Publish AMD64 and ARM64 images
+
+The script builds a Linux native image for each architecture with Paketo Buildpacks, pushes the architecture-specific tags with Docker CLI credentials, then publishes a multi-platform manifest. Docker, Buildx, and a registry login with push access to the target repository are required. On a host with a different architecture, Docker must support emulation for the target platform.
+
+```sh
+./scripts/build-multiarch-image.sh 1.0.0
+```
+
+The default repository is `${DOCKER_USERNAME:-dalbodeule}/dnsapi`. Set `IMAGE_REPOSITORY` to use another repository, such as `git.mori.space/dalbodeule/dnsapi`. The script publishes `:1.0.0-amd64`, `:1.0.0-arm64`, `:1.0.0`, and `:latest`; set `PUBLISH_LATEST=0` to leave `:latest` unchanged. Review the commands without publishing by setting `DRY_RUN=1`.
+
+If a previous run built an architecture image locally but failed while pushing, log in to the registry and rerun with `RESUME=1`. The script checks the local image architecture and skips its costly rebuild.
+
+```sh
+docker login --username dalbodeule
+RESUME=1 ./scripts/build-multiarch-image.sh 1.0.0
+```
+
 ## Update API documentation
 
 ```sh

build.gradle.kts

@@ -97,18 +97,24 @@ tasks.register("updateDocs") {
 
 tasks.withType<BootBuildImage> {
 	val dockerId = System.getenv("DOCKER_USERNAME") ?: "dalbodeule"
-	val dockerPw = System.getenv("DOCKER_PASSWORD") ?: ""
+	val dockerPw = System.getenv("DOCKER_PASSWORD")
 
 	docker {
 		publish = true
-		publishRegistry {
-			username = dockerId
-			password = dockerPw
+		if (!dockerPw.isNullOrBlank()) {
+			publishRegistry {
+				username = dockerId
+				password = dockerPw
+			}
 		}
 	}
 
 	imageName.set("$dockerId/dnsapi")
-	tags.set(setOf("$dockerId/dnsapi:latest", "$dockerId/dnsapi:${datetimeFormatter.format(LocalDateTime.now())}"))
+	if (providers.gradleProperty("multiArchImage").orNull == "true") {
+		tags.set(emptySet<String>())
+	} else {
+		tags.set(setOf("$dockerId/dnsapi:latest", "$dockerId/dnsapi:${datetimeFormatter.format(LocalDateTime.now())}"))
+	}
 	buildpacks.set(setOf("docker.io/paketobuildpacks/oracle", "urn:cnb:builder:paketo-buildpacks/java-native-image"))
 
 	environment = mapOf(

scripts/build-multiarch-image.sh

@@ -0,0 +1,79 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+usage() {
+  echo "Usage: $0 <image-tag>" >&2
+  echo "Set IMAGE_REPOSITORY to override the default repository." >&2
+  exit 2
+}
+
+if [[ $# -ne 1 ]]; then
+  usage
+fi
+
+tag=$1
+if [[ ! $tag =~ ^[A-Za-z0-9_][A-Za-z0-9_.-]{0,121}$ ]]; then
+  echo "Invalid Docker image tag: $tag" >&2
+  exit 2
+fi
+
+repository=${IMAGE_REPOSITORY:-${DOCKER_USERNAME:-dalbodeule}/dnsapi}
+publish_latest=${PUBLISH_LATEST:-1}
+dry_run=${DRY_RUN:-0}
+resume=${RESUME:-0}
+root_dir=$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)
+
+if [[ $publish_latest != 0 && $publish_latest != 1 ]]; then
+  echo "PUBLISH_LATEST must be 0 or 1" >&2
+  exit 2
+fi
+if [[ $dry_run != 0 && $dry_run != 1 ]]; then
+  echo "DRY_RUN must be 0 or 1" >&2
+  exit 2
+fi
+if [[ $resume != 0 && $resume != 1 ]]; then
+  echo "RESUME must be 0 or 1" >&2
+  exit 2
+fi
+if [[ $dry_run == 0 ]]; then
+  command -v docker >/dev/null || { echo "Docker is required" >&2; exit 1; }
+  docker buildx version >/dev/null
+fi
+
+run() {
+  if [[ $dry_run == 1 ]]; then
+    printf 'DRY RUN:'
+    printf ' %q' "$@"
+    printf '\n'
+  else
+    "$@"
+  fi
+}
+
+cd "$root_dir"
+for arch in amd64 arm64; do
+  image="$repository:$tag-$arch"
+  if [[ $resume == 1 && $dry_run == 0 ]] && docker image inspect "$image" >/dev/null 2>&1; then
+    actual_platform=$(docker image inspect "$image" --format '{{.Os}}/{{.Architecture}}')
+    if [[ $actual_platform != "linux/$arch" ]]; then
+      echo "$image has platform $actual_platform, expected linux/$arch" >&2
+      exit 1
+    fi
+    echo "Reusing local image $image"
+  else
+    run ./gradlew bootBuildImage \
+      -PmultiArchImage=true \
+      "--imagePlatform=linux/$arch" \
+      "--imageName=$image" \
+      --no-publishImage
+  fi
+  run docker push "$image"
+done
+
+manifest_args=(docker buildx imagetools create --tag "$repository:$tag")
+if [[ $publish_latest == 1 ]]; then
+  manifest_args+=(--tag "$repository:latest")
+fi
+manifest_args+=("$repository:$tag-amd64" "$repository:$tag-arm64")
+run "${manifest_args[@]}"
+run docker buildx imagetools inspect "$repository:$tag"