This sample shows how to use Oracle GraalVM in OCI DevOps build pipelines to build a simple Micronaut hello world REST application. You can use this approach to build any high performance Java application with Micronaut, Oracle GraalVM and OCI DevOps.
GraalVM is a high performance JDK distribution that can accelerate any Java workload running on the HotSpot JVM.
GraalVM Native Image ahead-of-time compilation enables you to build lightweight Java applications that are smaller, faster, and use less memory and CPU. At build time, GraalVM Native Image analyzes a Java application and its dependencies to identify just what classes, methods, and fields are absolutely necessary and generates optimized machine code for just those elements.
Oracle GraalVM is available for use on Oracle Cloud Infrastructure (OCI) at no additional cost.
Micronaut is a modern, JVM-based framework to build modular, easily testable microservice and serverless applications. By avoiding runtime reflection in favor of annotation processing, Micronaut improves the Java-based development experience by detecting errors at compile time instead of runtime, and improves Java-based application start time and memory footprint. Micronaut includes a persistence framework called Micronaut Data that precomputes your SQL queries at compilation time making it a great fit for working with databases like MySQL, Oracle Autonomous Database, etc.
Micronaut uses GraalVM Native Image to build lightweight Java applications that use less memory and CPUs, are smaller and faster because of an advanced ahead-of-time compilation technology.
OCI DevOps services provide a continuous integration and deployment (CI/CD) platform for developers to automate the build, test, and deployment of software applications on Oracle Cloud.
OCI DevOps build and deployment pipelines reduce change-driven errors and decrease the time customers spend on building and deploying software. The service also provides private Git repositories to store your code and supports connections to external code repositories.
To install and use Oracle GraalVM in the DevOps build pipeline, update your build specification file as follows:
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Add the following command to install the required Oracle GraalVM components. For example, this command installs Native Image along with the Java Development Kit (JDK) and other necessary dependencies.
steps: - type: Command name: "Install the latest Oracle GraalVM for JDK 17 - JDK and Native Image" command: | yum -y install graalvm-17-native-image -
Set the JAVA_HOME environment variable.
env: variables: "JAVA_HOME" : "/usr/lib64/graalvm/graalvm-java17" -
Set the PATH environment variable.
env: variables: # PATH is a reserved variable and cannot be defined as a variable. # PATH can be changed in a build step and the change is visible in subsequent steps. steps: - type: Command name: "Set the PATH here" command: | export PATH=$JAVA_HOME/bin:$PATH -
Build a native executable for your Micronaut application.
steps: - type: Command name: "Example 2: Build a native executable with Oracle GraalVM for JDK 17 - Native Image" command: | ./mvnw --no-transfer-progress package -Dpackaging=native-image -
The native executable file is available under
target/MnHelloRest.outputArtifacts: - name: app_native_executable type: BINARY location: target/MnHelloRest -
Package the native executable in a lightweight distroless runtime container image.
steps: - type: Command name: "Package the native executable in a runtime container image" command: | docker build -f ./Dockerfile \ --build-arg APP_FILE=${APP_FILE} \ -t ${TAG} . -
The runtime container image is available as a build output artifact.
outputArtifacts: - name: runtime_image type: DOCKER_IMAGE location: ${TAG}
Here's the complete build specification file.
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The
yum installbuild log statements should be similar to:... EXEC: Installed: EXEC: graalvm-17-native-image.x86_64 0:17.0.7-2.el7 EXEC: EXEC: Dependency Installed: EXEC: glibc-static.x86_64 0:2.17-326.0.5.el7_9 EXEC: graalvm-17-jdk.x86_64 0:17.0.7-2.el7 EXEC: libstdc++-static.x86_64 0:4.8.5-44.0.3.el7 EXEC: zlib-static.x86_64 0:1.2.7-21.el7_9 EXEC: EXEC: Dependency Updated: EXEC: glibc.x86_64 0:2.17-326.0.5.el7_9 EXEC: glibc-common.x86_64 0:2.17-326.0.5.el7_9 EXEC: glibc-devel.x86_64 0:2.17-326.0.5.el7_9 EXEC: glibc-headers.x86_64 0:2.17-326.0.5.el7_9 EXEC: EXEC: Complete! ... -
The native executable build log statements should be similar to:
... EXEC: ======================================================================================================================== EXEC: GraalVM Native Image: Generating 'MnHelloRest' (static executable)... EXEC: ======================================================================================================================== EXEC: [1/8] Initializing... (9.1s @ 0.14GB) EXEC: Java version: 17.0.7+8-LTS, vendor version: Oracle GraalVM 17.0.7+8.1 EXEC: Graal compiler: optimization level: 2, target machine: x86-64-v3, PGO: ML-inferred EXEC: C compiler: gcc (redhat, x86_64, 4.8.5) EXEC: Garbage collector: Serial GC (max heap size: 80% of RAM) EXEC: 4 user-specific feature(s) EXEC: - io.micronaut.buffer.netty.NettyFeature EXEC: - io.micronaut.core.graal.ServiceLoaderFeature EXEC: - io.micronaut.http.netty.graal.HttpNettyFeature EXEC: - io.micronaut.jackson.JacksonDatabindFeature EXEC: [2/8] Performing analysis... [*******] (93.5s @ 1.62GB) EXEC: 15,049 (90.10%) of 16,702 types reachable EXEC: 22,193 (58.56%) of 37,896 fields reachable EXEC: 83,299 (64.28%) of 129,589 methods reachable EXEC: 4,924 types, 354 fields, and 4,053 methods registered for reflection EXEC: 63 types, 68 fields, and 55 methods registered for JNI access EXEC: 4 native libraries: dl, pthread, rt, z EXEC: [3/8] Building universe... (13.4s @ 1.60GB) EXEC: [4/8] Parsing methods... [******] (34.0s @ 1.44GB) EXEC: [5/8] Inlining methods... [***] (3.9s @ 1.70GB) EXEC: [6/8] Compiling methods... [**************] (212.6s @ 2.31GB) EXEC: [7/8] Layouting methods... [****] (12.3s @ 1.83GB) EXEC: [8/8] Creating image... [***] (8.4s @ 2.58GB) EXEC: 44.56MB (60.14%) for code area: 48,635 compilation units EXEC: 28.98MB (39.12%) for image heap: 396,992 objects and 292 resources EXEC: 562.93kB ( 0.74%) for other data EXEC: 74.09MB in total EXEC: ------------------------------------------------------------------------------------------------------------------------ EXEC: Top 10 origins of code area: Top 10 object types in image heap: EXEC: 16.60MB java.base 9.59MB byte[] for code metadata EXEC: 4.34MB svm.jar 3.51MB byte[] for java.lang.String EXEC: 3.40MB java.xml 3.21MB java.lang.Class EXEC: 2.41MB jackson-databind-2.14.2.jar 2.63MB java.lang.String EXEC: 1.27MB netty-buffer-4.1.92.Final.jar 2.43MB byte[] for general heap data EXEC: 1.13MB micronaut-inject-3.9.3.jar 950.06kB byte[] for reflection metadata EXEC: 1.03MB reactor-core-3.5.0.jar 705.42kB com.oracle.svm.core.hub.DynamicHubCompanion EXEC: 915.53kB jdk.proxy4 437.38kB c.o.svm.core.hub.DynamicHub$ReflectionMetadata EXEC: 897.38kB micronaut-core-3.9.3.jar 435.69kB java.util.concurrent.ConcurrentHashMap$Node EXEC: 814.28kB netty-transport-4.1.92.Final.jar 424.75kB java.util.HashMap$Node EXEC: 11.48MB for 61 more packages 4.42MB for 3336 more object types EXEC: ------------------------------------------------------------------------------------------------------------------------ EXEC: Recommendations: EXEC: G1GC: Use the G1 GC ('--gc=G1') for improved latency and throughput. EXEC: PGO: Use Profile-Guided Optimizations ('--pgo') for improved throughput. EXEC: HEAP: Set max heap for improved and more predictable memory usage. EXEC: CPU: Enable more CPU features with '-march=native' for improved performance. EXEC: QBM: Use the quick build mode ('-Ob') to speed up builds during development. EXEC: ------------------------------------------------------------------------------------------------------------------------ EXEC: 35.5s (9.1% of total time) in 214 GCs | Peak RSS: 3.97GB | CPU load: 3.39 EXEC: ------------------------------------------------------------------------------------------------------------------------ EXEC: Produced artifacts: EXEC: /workspace/mn-hello/target/MnHelloRest (executable) EXEC: ======================================================================================================================== EXEC: Finished generating 'MnHelloRest' in 6m 28s. ...