以下のブログにしたがってBuildpacksとJibを試してみるメモ。
サンプルアプリケーション
サンプルリポジトリをクローンする。
git clone https://github.com/jamesward/comparing-docker-methods.git cd comparing-docker-methods
ローカルにインストールされているJavaとMavenを確認する。Corretto 8がインストールされているが、MavenはOpenJDK 17を使っている。
$ java -version openjdk version "1.8.0_312" OpenJDK Runtime Environment Corretto-8.312.07.1 (build 1.8.0_312-b07) OpenJDK 64-Bit Server VM Corretto-8.312.07.1 (build 25.312-b07, mixed mode) $ mvn -version Apache Maven 3.8.4 (9b656c72d54e5bacbed989b64718c159fe39b537) Maven home: /usr/local/Cellar/maven/3.8.4/libexec Java version: 17.0.1, vendor: Homebrew, runtime: /usr/local/Cellar/openjdk/17.0.1/libexec/openjdk.jdk/Contents/Home Default locale: ja_JP, platform encoding: UTF-8 OS name: "mac os x", version: "11.6.1", arch: "x86_64", family: "mac"
Maven Wrapperが入っていなかったので入れる。
mvn -N io.takari:maven:0.7.7:wrapper
アプリケーションを実行する。
./mvnw compile exec:java
アプリケーションにアクセスする。
$ curl localhost:8080 hello, world%
Buildpacks
packコマンドをインストールする。
brew install buildpacks/tap/pack
どのビルダーが使えるのかはサジェストしてくれる。
$ pack builder suggest
Suggested builders:
Google: gcr.io/buildpacks/builder:v1 Ubuntu 18 base image with buildpacks for .NET, Go, Java, Node.js, and Python
Heroku: heroku/buildpacks:18 Base builder for Heroku-18 stack, based on ubuntu:18.04 base image
Heroku: heroku/buildpacks:20 Base builder for Heroku-20 stack, based on ubuntu:20.04 base image
Paketo Buildpacks: paketobuildpacks/builder:base Ubuntu bionic base image with buildpacks for Java, .NET Core, NodeJS, Go, Python, Ruby, NGINX and Procfile
Paketo Buildpacks: paketobuildpacks/builder:full Ubuntu bionic base image with buildpacks for Java, .NET Core, NodeJS, Go, Python, PHP, Ruby, Apache HTTPD, NGINX and Procfile
Paketo Buildpacks: paketobuildpacks/builder:tiny Tiny base image (bionic build image, distroless-like run image) with buildpacks for Java, Java Native Image and Go
Tip: Learn more about a specific builder with:
pack builder inspect <builder-image>
イメージを全部消す。
docker images -aq | xargs docker rmi -f
イメージをビルドする。
$ pack build --builder=gcr.io/buildpacks/builder:v1 comparing-docker-methods:buildpacks
v1: Pulling from buildpacks/builder
...
Digest: sha256:ae9956349502a7d9b340651ddc536e80821c254c77c16f30742216322b3eff87
Status: Downloaded newer image for gcr.io/buildpacks/builder:v1
v1: Pulling from buildpacks/gcp/run
...
Digest: sha256:3f45378eae3d66d960c6e09ea86739aa568744638f90e40b35b26c254d2f3c27
Status: Downloaded newer image for gcr.io/buildpacks/gcp/run:v1
===> DETECTING
4 of 5 buildpacks participating
google.java.runtime 0.9.1
google.java.maven 0.9.0
google.java.entrypoint 0.9.0
google.utils.label 0.0.1
===> ANALYZING
Previous image with name "comparing-docker-methods:buildpacks" not found
Restoring metadata for "google.java.maven:m2" from cache
===> RESTORING
Restoring data for "google.java.maven:m2" from cache
===> BUILDING
=== Java - Runtime (google.java.runtime@0.9.1) ===
Using latest Java 11 runtime version. You can specify a different version with GOOGLE_RUNTIME_VERSION: https://github.com/GoogleCloudPlatform/buildpacks#configuration
--------------------------------------------------------------------------------
Running "curl --fail --show-error --silent --location https://api.adoptopenjdk.net/v3/assets/feature_releases/11/ga?architecture=x64&heap_size=normal&image_type=jdk&jvm_impl=hotspot&os=linux&page=0&page_size=1&project=jdk&sort_order=DESC&vendor=adoptopenjdk"
[
{
"binaries": [
{
"architecture": "x64",
"download_count": 166661,
"heap_size": "normal",
"image_type": "jdk",
"jvm_impl": "hotspot",
"os": "linux",
"package": {
"checksum": "3b1c0c34be4c894e64135a454f2d5aaa4bd10aea04ec2fa0c0efe6bb26528e30",
"checksum_link": "https://github.com/adoptium/temurin11-binaries/releases/download/jdk-11.0.13%2B8/OpenJDK11U-jdk_x64_linux_hotspot_11.0.13_8.tar.gz.sha256.txt",
"download_count": 166661,
"link": "https://github.com/adoptium/temurin11-binaries/releases/download/jdk-11.0.13%2B8/OpenJDK11U-jdk_x64_linux_hotspot_11.0.13_8.tar.gz",
"metadata_link": "https://github.com/adoptium/temurin11-binaries/releases/download/jdk-11.0.13%2B8/OpenJDK11U-jdk_x64_linux_hotspot_11.0.13_8.tar.gz.json",
"name": "OpenJDK11U-jdk_x64_linux_hotspot_11.0.13_8.tar.gz",
"size": 192958006
},
"project": "jdk",
"scm_ref": "jdk-11.0.13+8_adopt",
"updated_at": "2021-10-21T21:55:42Z"
}
],
"download_count": 508086,
"id": "MDc6UmVsZWFzZTUxODI0ODA2.DrSSnWfQGA0+fw==",
"release_link": "https://github.com/adoptium/temurin11-binaries/releases/tag/jdk-11.0.13%2B8",
"release_name": "jdk-11.0.13+8",
"release_type": "ga",
"source": {
"link": "https://github.com/adoptium/temurin11-binaries/releases/download/jdk-11.0.13%2B8/OpenJDK11U-sources_11.0.13_8.tar.gz",
"name": "OpenJDK11U-sources_11.0.13_8.tar.gz",
"size": 123491655
},
"timestamp": "2021-10-21T21:55:18Z",
"updated_at": "2021-11-15T16:03:02Z",
"vendor": "eclipse",
"version_data": {
"build": 8,
"major": 11,
"minor": 0,
"openjdk_version": "11.0.13+8",
"security": 13,
"semver": "11.0.13+8"
}
}
]Done "curl --fail --show-error --silent --location https://api.ado..." (850.3602ms)
Installing Java v11.0.13+8
--------------------------------------------------------------------------------
Running "bash -c curl --fail --show-error --silent --location --retry 3 https://github.com/adoptium/temurin11-binaries/releases/download/jdk-11.0.13%2B8/OpenJDK11U-jdk_x64_linux_hotspot_11.0.13_8.tar.gz | tar xz --directory /layers/google.java.runtime/java --strip-components=1"
Done "bash -c curl --fail --show-error --silent --location --retry..." (18.2298941s)
=== Java - Maven (google.java.maven@0.9.0) ===
--------------------------------------------------------------------------------
Running "./mvnw clean package --batch-mode -DskipTests -Dhttp.keepAlive=false --quiet"
Done "./mvnw clean package --batch-mode -DskipTests -Dhttp.keepAli..." (6.8467339s)
=== Java - Entrypoint (google.java.entrypoint@0.9.0) ===
WARNING: Launch layer is setting default=true, but that is not supported until API version 0.6. This setting will be ignored.
Warning: Warning: default processes aren't supported in this buildpack api version. Overriding the default value to false for the following processes: [web]
=== Utils - Label Image (google.utils.label@0.0.1) ===
===> EXPORTING
Adding layer 'google.java.runtime:java'
Adding 1/1 app layer(s)
Adding layer 'launcher'
Adding layer 'config'
Adding layer 'process-types'
Adding label 'io.buildpacks.lifecycle.metadata'
Adding label 'io.buildpacks.build.metadata'
Adding label 'io.buildpacks.project.metadata'
Setting default process type 'web'
Saving comparing-docker-methods:buildpacks...
*** Images (d9a7fa05282b):
comparing-docker-methods:buildpacks
Reusing cache layer 'google.java.runtime:java'
Reusing cache layer 'google.java.maven:m2'
Successfully built image comparing-docker-methods:buildpacks
イメージを確認する。作成日付がおかしい。
$ docker images REPOSITORY TAG IMAGE ID CREATED SIZE gcr.io/buildpacks/builder v1 0be9c8be1372 34 hours ago 626MB gcr.io/buildpacks/gcp/run v1 e9c0a00a124f 34 hours ago 120MB comparing-docker-methods buildpacks d9a7fa05282b 41 years ago 444MB
イメージを実行する。
docker run -it -ePORT=8080 -p8080:8080 comparing-docker-methods:buildpacks
アクセス確認する。
$ curl localhost:8080 hello, world%
diveでイメージを見てみる。
dive comparing-docker-methods:buildpacks
ビルド時のメッセージと比較して見ると以下だと思われる。
| サイズ | 中身 |
|---|---|
| （上の5レイヤー） | gcr.io/buildpacks/gcp/run:v1 |
| 321 MB | Adding layer 'google.java.runtime:java' |
| 177 kB | Adding 1/1 app layer(s) |
| 2.5 MB | Adding layer 'launcher' |
| 675 B | Adding layer 'config' |
| 0 B | Adding layer 'process-types' |
メッセージからすると、Buildpacksもレイヤリングしてくれそう。
Jib
pom.xmlに以下を追加する。
<plugin> <groupId>com.google.cloud.tools</groupId> <artifactId>jib-maven-plugin</artifactId> <version>2.6.0</version> </plugin>
イメージを全部消す。
docker images -aq | xargs docker rmi -f
コンテナイメージをビルドしてローカルに保存する。
$ ./mvnw compile jib:dockerBuild -Dimage=comparing-docker-methods:jib [INFO] Scanning for projects... [INFO] [INFO] ---------------------< com.google:sample-java-mvn >--------------------- [INFO] Building sample-java-mvn 0.1.0-SNAPSHOT [INFO] --------------------------------[ jar ]--------------------------------- [INFO] [INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ sample-java-mvn --- [WARNING] Using platform encoding (UTF-8 actually) to copy filtered resources, i.e. build is platform dependent! [INFO] skip non existing resourceDirectory /Users/sotosugi/workspace/2021/aisac/buildpacks/comparing-docker-methods/src/main/resources [INFO] [INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ sample-java-mvn --- [INFO] Nothing to compile - all classes are up to date [INFO] [INFO] --- jib-maven-plugin:2.6.0:dockerBuild (default-cli) @ sample-java-mvn --- [INFO] [INFO] Containerizing application to Docker daemon as comparing-docker-methods:jib... [WARNING] Base image 'gcr.io/distroless/java:8' does not use a specific image digest - build may not be reproducible [INFO] Using base image with digest: sha256:34c3598d83f0dba27820323044ebe79e63ad4f137b405676da75a3905a408adf [INFO] [INFO] Container entrypoint set to [java, -cp, /app/resources:/app/classes:/app/libs/*, com.google.WebApp] [INFO] [INFO] Built image to Docker daemon as comparing-docker-methods:jib [INFO] Executing tasks: [INFO] [==============================] 100.0% complete [INFO] [INFO] ------------------------------------------------------------------------ [INFO] BUILD SUCCESS [INFO] ------------------------------------------------------------------------ [INFO] Total time: 9.371 s [INFO] Finished at: 2021-11-26T16:24:06+09:00 [INFO] ------------------------------------------------------------------------
イメージを確認する。メッセージにでているが、ベースイメージがgcr.io/distroless/java:8なのでサイズが小さい。
$ docker images REPOSITORY TAG IMAGE ID CREATED SIZE comparing-docker-methods jib 625395395d3e 51 years ago 130MB
diveで見てみると、最後の前のレイヤーでディレクトリが作られ、最後のレイヤーでjarが置かれているように見える。
Dockerfile
Dockerfileを作成する。このadoptopenjdk/openjdk8のイメージはUbuntuベースのイメージのようだ。
FROM adoptopenjdk/openjdk8 as builder WORKDIR /app COPY . /app RUN ./mvnw compile jar:jar FROM adoptopenjdk/openjdk8:jre COPY --from=builder /app/target/*.jar /server.jar CMD ["java", "-jar", "/server.jar"]
イメージを全部消す。
docker images -aq | xargs docker rmi -f
ビルドする。
docker build -t comparing-docker-methods:dockerfile .
確認する。
$ docker images REPOSITORY TAG IMAGE ID CREATED SIZE comparing-docker-methods dockerfile 42980788df0c 46 seconds ago 224MB
GraalVMを使う方法は省略。
まとめ
packとjibでビルドし直し、またベースイメージもpullして、関連したイメージを全部まとめて一覧表示する。
$ docker images REPOSITORY TAG IMAGE ID CREATED SIZE comparing-docker-methods dockerfile 42980788df0c 17 minutes ago 224MB gcr.io/buildpacks/builder v1 0be9c8be1372 35 hours ago 626MB gcr.io/buildpacks/gcp/run v1 e9c0a00a124f 35 hours ago 120MB adoptopenjdk/openjdk8 jre 4e41c2a5a301 40 hours ago 224MB adoptopenjdk/openjdk8 latest f5be1fb5cc77 40 hours ago 320MB comparing-docker-methods buildpacks fb4cfe8a43ed 41 years ago 444MB comparing-docker-methods jib 625395395d3e 51 years ago 130MB gcr.io/distroless/java 8 b762aad6c014 51 years ago 130MB
