Add AOT cache for mc-image-helper on Java 25+ (#4341)

.github/workflows/build.yml

@@ -49,18 +49,22 @@ jobs:
             baseImage: eclipse-temurin:25-jre-noble
             platforms: linux/amd64,linux/arm64,linux/riscv64
             mcVersion: latest
+            enableMcHelperAotWarmup: true
           - variant: java25-alpine
             baseImage: eclipse-temurin:25-jre-alpine
             platforms: linux/amd64,linux/arm64
             mcVersion: latest
+            enableMcHelperAotWarmup: true
           - variant: java25-jdk
             baseImage: eclipse-temurin:25
             platforms: linux/amd64,linux/arm64
             mcVersion: latest
+            enableMcHelperAotWarmup: true
           - variant: java25-graalvm
             baseImage: container-registry.oracle.com/graalvm/jdk:25-ol10
             platforms: linux/amd64,linux/arm64
             mcVersion: latest
+            enableMcHelperAotWarmup: true
         # JAVA 21:
           - variant: java21
             baseImage: eclipse-temurin:21-jre
@@ -240,6 +244,7 @@ jobs:
             REVISION=${{ fromJSON(steps.meta.outputs.json).labels['org.opencontainers.image.revision'] }}
             ${{ matrix.mcHelperVersion && format('MC_HELPER_VERSION={0}', matrix.mcHelperVersion) }}
             ${{ matrix.knockdRepoOrg && format('KNOCKD_REPO_ORG={0}', matrix.knockdRepoOrg) }}
+            ${{ matrix.enableMcHelperAotWarmup && 'ENABLE_MC_HELPER_AOT_WARMUP=1' || 'ENABLE_MC_HELPER_AOT_WARMUP=0' }}
             IMAGE_AUTHOR=${{ env.IMAGE_AUTHOR }}
           cache-from: type=gha,scope=${{ matrix.variant }}
           cache-to: type=gha,mode=max,scope=${{ matrix.variant }}

.github/workflows/verify-pr.yml

@@ -34,17 +34,20 @@ jobs:
             baseImage: eclipse-temurin:25-jre-noble
             platforms: linux/amd64,linux/arm64
             mcVersion: latest
+            enableMcHelperAotWarmup: true
           - variant: java25-alpine
             baseImage: eclipse-temurin:25-jre-alpine
             platforms: linux/amd64,linux/arm64
             mcVersion: latest
             # For GLIBC_2.34 support (and Alpine)
             knockdRepoOrg: Metalcape/knock
+            enableMcHelperAotWarmup: true
           - variant: java25-graalvm
             # stay aligned with build.yml
             baseImage: container-registry.oracle.com/graalvm/jdk:25-ol10
             platforms: linux/amd64,linux/arm64
             mcVersion: latest
+            enableMcHelperAotWarmup: true
         # JAVA 17:
           - variant: java17
             # jammy doesn't work until minecraft updates to https://github.com/netty/netty/issues/12343
@@ -107,6 +110,7 @@ jobs:
             BASE_IMAGE=${{ matrix.baseImage }}
             ${{ matrix.mcHelperVersion && format('MC_HELPER_VERSION={0}', matrix.mcHelperVersion) }}
             ${{ matrix.knockdRepoOrg && format('KNOCKD_REPO_ORG={0}', matrix.knockdRepoOrg) }}
+            ${{ matrix.enableMcHelperAotWarmup && 'ENABLE_MC_HELPER_AOT_WARMUP=1' || 'ENABLE_MC_HELPER_AOT_WARMUP=0' }}
           cache-from: type=gha,scope=${{ matrix.variant }}
 
       - name: Run tests

Dockerfile

@@ -66,6 +66,12 @@ RUN curl -fsSL ${MC_HELPER_BASE_URL}/mc-image-helper-${MC_HELPER_VERSION}.tgz \
     && ln -s /usr/share/mc-image-helper-${MC_HELPER_VERSION}/ /usr/share/mc-image-helper \
     && ln -s /usr/share/mc-image-helper/bin/mc-image-helper /usr/bin
 
+
+ENV MC_IMAGE_HELPER_AOT_CACHE=/usr/share/mc-image-helper/cache/aot.cache
+ARG ENABLE_MC_HELPER_AOT_WARMUP=0
+RUN --mount=target=/build,source=build \
+    /build/create-aot-cache.sh
+
 VOLUME ["/data"]
 WORKDIR /data
 

build/create-aot-cache.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+
+set -e
+if [ "${ENABLE_MC_HELPER_AOT_WARMUP}" = "1" ]; then
+  echo "Warming mc-image-helper AOT cache at ${MC_IMAGE_HELPER_AOT_CACHE}"
+  mkdir -p "$(dirname "${MC_IMAGE_HELPER_AOT_CACHE}")"
+
+  aot_config=/tmp/mc-image-helper.aotconf
+  # record config
+  if ! MC_IMAGE_HELPER_OPTS="-XX:AOTMode=record -XX:AOTConfiguration=${aot_config}" mc-image-helper java-release > /dev/null; then
+    echo "Failed to record AOT configuration"
+    exit 1
+  fi
+
+  # create cache
+  if ! MC_IMAGE_HELPER_OPTS="-XX:AOTMode=create -XX:AOTConfiguration=${aot_config} -XX:AOTCache=${MC_IMAGE_HELPER_AOT_CACHE}" mc-image-helper java-release > /dev/null; then
+    echo "Failed to create AOT cache"
+    exit 1
+  fi
+else
+  echo "Skipping mc-image-helper AOT warmup"
+fi

scripts/start-configuration

@@ -65,6 +65,12 @@ if isTrue "${DEBUG_MEMORY:-false}"; then
   free -m | applyLogPrefix
 fi
 
+: "${MC_IMAGE_HELPER_AOT_CACHE:=/usr/share/mc-image-helper/cache/aot.cache}"
+if (( $(getJavaRelease) >= 25 )) && [ -f "${MC_IMAGE_HELPER_AOT_CACHE}" ]; then
+  MC_IMAGE_HELPER_OPTS+=" -XX:AOTMode=auto -XX:AOTCache=${MC_IMAGE_HELPER_AOT_CACHE}"
+  export MC_IMAGE_HELPER_OPTS
+fi
+
 ##########################################
 # Setup RCON password