Java 11应用程序作为轻量级码头映像

Question

受为什么Java 11基本码头映像如此之大？(openjdk:11-jre-slim)问题的启发，我发现这个主题在Java中仍然没有解决。

至于07 Dec 2018，有一些常见的问题/陷阱(在上面的票证中讨论过)：

• JRE不是作为一个单独的“包”分发的。应该使用来自JDK的模块。
• 甲骨文OpenJDK 11不支持Linux阿尔卑斯，所以很难创建轻量级映像

- In the same time current stable Debian versions still doesn't have [Java 11 packages](https://packages.debian.org/stable/java/) ([Ubuntu has Java 10 installed](https://packages.ubuntu.com/bionic/java/) under openjdk-11 packages), that's why unstable sid versions are used for base docker images

​

• 当前可用的OracleOpenJDK-11映像构建未剥离的libjvm.so模块，该模块有数百兆字节，必须单独删除：

- [jlink runtime image size (specifically libjvm.so) created from openjdk is huge. Expected it to be much smaller.](https://github.com/docker-library/openjdk/issues/217)
- Solution: [https://github.com/docker-library/openjdk/issues/217#issuecomment-436079779](https://github.com/docker-library/openjdk/issues/217#issuecomment-436079779)

​

由于这些问题，即使是苗条的Oracle 11基映像也很重，并且被认为是不稳定的：/openjdk/

所以问题是：

什么是优化的或推荐以E 227构建和交付Java 11应用程序的方法

Answer 1

UPD来自07.2019：https://stackoverflow.com/a/57145029/907576

以简单的spring引导应用程序(只有一个REST端点)为例，到目前为止，我能够找到以下解决方案(考虑到应用程序jar在Docker之前位于build/libs/spring-boot-demo.jar )：

1. 绝地路径如果我们想在稳定的瘦Linux版本上使用官方的甲骨文OpenJDK发行版(目前是Debian 9 "Stretch")：

- use `debian:stretch-slim` (latest stable) base image
- use [Docker multi-stage build](https://docs.docker.com/develop/develop-images/multistage-build/)

    1. First Docker build stage: 

        - download and install `Oracle OpenJDK` archive on the first Docker build stage
        - compile Java minimal distribution for your project (aka JRE) using `jlink` tool

​

    1. Second Docker build stage:

        - copy compiled minimal Java distribution from stage 1 to the new image
        - configure path to access Java
        - copy application jar to the image

​

​

所以，最终的Dockerfile看起来像这样

( VERSION**，实现JDK ** URL 和 HASH value)：

第一阶段: JDK 11，包含debian的Spring所需的模块:Extension-瘦作为包#源JDK发行名称# https://jdk.java.net/java-se-ri/11 ENV JDK_VERSION="11.0.1“ENV JDK_URL="bin.tar.gz”ENV https://jdk.java.net/java-se-ri/11 ENV JDK_HASH_FILE="${JDK_ARJ_FILE}.sha2“ENV JDK_ARJ_FILE="openjdk-${JDK_VERSION}.tar.gz”#目标JDK安装名称ENV OPT="/opt“ENV JKD_DIR_NAME="jdk-${JDK”_VERSION}“ENV JAVA_HOME=”${OPT}{JKD_DIR_NAME}“ENV JAVA_MINIMAL=”${OPT}/java-在本地文件中添加"$JDK_URL“"$JDK_ARJ_FILE”#校验下载的文件hashsum运行{\ echo验证下载的JDK文件$JDK_ARJ_FILE：&\ echo "$JDK_HASH $JDK_ARJ_FILE“> "$JDK_HASH_FILE”&\sha256sum -c "$JDK_HASH_FILE“；\}#提取JDK并添加到路径运行{\ echo“卸载下载的JDK到${JAVA_HOME}/:”&\ mkdir -p "$OPT“&& tar xf "$JDK_ARJ_FILE”-C "$OPT“；\} ENV PATH="$ PATH :$ java _HOME/bin”运行{\java-version；回显"jlink版本：“&& jlink -版本；#构建模块发行版运行jlink \--详细的\-附加模块\ java.base、java.sql、java.naming、java.desktop、java.management、java.security.jgss、java/lang/instrument/IllegalClassFormatException \# java.naming /命名/NamingException# java.desktop -java/bean/PropertyEditorSupport# java.management - javax/management/MBeanServer # java.security.jgss - org/ietf/jgss/GSSException # java.instrument -压缩2\-条形-调试\-无头文件-无-man-页面\-输出"$JAVA_MINIMAL“#第二阶段只添加我们最小的"JRE“发行版和我们来自debian的应用程序:拉伸-苗条ENV _HOME=/opt/java-最小ENV PATH="$PATH:$JAVA_HOME/bin”COPY - FROM =packager "$JAVA_HOME“"$JAVA_HOME”COPY“build/libs/spring demo.jar”"/app.jar“公开8080 CMD "-jar"，"/app.jar”ENTRYPOINT "java“

Note：

- there are 5 java modules included to the minimal JRE example (`java.base,java.sql,java.naming,java.desktop,java.management,java.security.jgss,java.instrument`). I found them "manually" running the application and fixing `ClassNotFoundException`. Waiting for some further Spring Boot developers recommendations/guides which Java modules to include and when, as same as removing some redundant dependencies, like `java.desktop`, which seems to be used only for `PropertyEditorSupport`
- if you are afraid to miss some modules - they are quite lightweight and all of them together give about 2 MB size increasing. Get a full list of `java.*` and `jdk.*` 11 modules:

java --list-modules | grep -E "^java\.[^@]*" | cut -d @ -f 1

java --list-modules | grep -E "^jdk\.[^@]*" | cut -d @ -f 1

在我的例子中，得到的映像大小是123 MB和最小7个Spring模块，125 MB和所有java.*模块

作为此构建工作流的可选改进

- Pre-build an image with downloaded and extracted JDK and use it as a base image for first stage
- if you know which modules to include every time - pre-build a base image with compiled minimal JRE and included modules

​

1. 使用供应商的Open发行版的简单方法： 相对于甲骨文，阿祖尔的祖鲁JDK 11支持高山港，并有各自的基本码头形象。

因此，如果Zulu JVM/JDK得到尊重，Docker构建就会简单得多：

FROM azul/zulu-openjdk-alpine:11 as packager

RUN { \
        java --version ; \
        echo "jlink version:" && \
        jlink --version ; \
    }

ENV JAVA_MINIMAL=/opt/jre

# build modules distribution
RUN jlink \
    --verbose \
    --add-modules \
        java.base,java.sql,java.naming,java.desktop,java.management,java.security.jgss,java.instrument \
        # java.naming - javax/naming/NamingException
        # java.desktop - java/beans/PropertyEditorSupport
        # java.management - javax/management/MBeanServer
        # java.security.jgss - org/ietf/jgss/GSSException
        # java.instrument - java/lang/instrument/IllegalClassFormatException
    --compress 2 \
    --strip-debug \
    --no-header-files \
    --no-man-pages \
    --output "$JAVA_MINIMAL"

# Second stage, add only our minimal "JRE" distr and our app
FROM alpine

ENV JAVA_MINIMAL=/opt/jre
ENV PATH="$PATH:$JAVA_MINIMAL/bin"

COPY --from=packager "$JAVA_MINIMAL" "$JAVA_MINIMAL"
COPY "build/libs/spring-boot-demo.jar" "/app.jar"

EXPOSE 8080
CMD [ "-jar", "/app.jar" ]
ENTRYPOINT [ "java" ]

得到的映像为73 MB，与剥离的高山发行版预期的一样。

Answer 2

截至07.2019

(Note：第一级图像可以像你想的那样胖:你可以使用debian/ubuntu/什么，包括git/gradle/什么-这不会影响最终的图像大小，这完全是基于最后(第二阶段))

使用高山社区储存库

FROM alpine:latest as packager

RUN apk --no-cache add openjdk11-jdk openjdk11-jmods

ENV JAVA_MINIMAL="/opt/java-minimal"

# build minimal JRE
RUN /usr/lib/jvm/java-11-openjdk/bin/jlink \
    --verbose \
    --add-modules \
        java.base,java.sql,java.naming,java.desktop,java.management,java.security.jgss,java.instrument \
    --compress 2 --strip-debug --no-header-files --no-man-pages \
    --release-info="add:IMPLEMENTOR=radistao:IMPLEMENTOR_VERSION=radistao_JRE" \
    --output "$JAVA_MINIMAL"

FROM alpine:latest

ENV JAVA_HOME=/opt/java-minimal
ENV PATH="$PATH:$JAVA_HOME/bin"

COPY --from=packager "$JAVA_HOME" "$JAVA_HOME"
COPY build/libs/application.jar app.jar

ENTRYPOINT ["java","-jar","/app.jar"]

使用AdoptOpenJDK

FROM adoptopenjdk/openjdk11:x86_64-alpine-jdk-11.0.4_11 as packager

ENV JAVA_MINIMAL="/opt/java-minimal"

# build minimal JRE
RUN jlink \
    --verbose \
    --add-modules \
        java.base,java.sql,java.naming,java.desktop,java.management,java.security.jgss,java.instrument \
    --compress 2 --strip-debug --no-header-files --no-man-pages \
    --output "$JAVA_MINIMAL"

FROM alpine:latest

# magic to make Java binaries work in Alpine
# https://github.com/AdoptOpenJDK/openjdk-docker/blob/master/11/jdk/alpine/Dockerfile.hotspot.releases.slim#L24-L54
RUN apk add --no-cache --virtual .build-deps curl binutils \
    && GLIBC_VER="2.29-r0" \
    && ALPINE_GLIBC_REPO="https://github.com/sgerrand/alpine-pkg-glibc/releases/download" \
    && GCC_LIBS_URL="https://archive.archlinux.org/packages/g/gcc-libs/gcc-libs-9.1.0-2-x86_64.pkg.tar.xz" \
    && GCC_LIBS_SHA256="91dba90f3c20d32fcf7f1dbe91523653018aa0b8d2230b00f822f6722804cf08" \
    && ZLIB_URL="https://archive.archlinux.org/packages/z/zlib/zlib-1%3A1.2.11-3-x86_64.pkg.tar.xz" \
    && ZLIB_SHA256=17aede0b9f8baa789c5aa3f358fbf8c68a5f1228c5e6cba1a5dd34102ef4d4e5 \
    && curl -LfsS https://alpine-pkgs.sgerrand.com/sgerrand.rsa.pub -o /etc/apk/keys/sgerrand.rsa.pub \
    && SGERRAND_RSA_SHA256="823b54589c93b02497f1ba4dc622eaef9c813e6b0f0ebbb2f771e32adf9f4ef2" \
    && echo "${SGERRAND_RSA_SHA256} */etc/apk/keys/sgerrand.rsa.pub" | sha256sum -c - \
    && curl -LfsS ${ALPINE_GLIBC_REPO}/${GLIBC_VER}/glibc-${GLIBC_VER}.apk > /tmp/glibc-${GLIBC_VER}.apk \
    && apk add /tmp/glibc-${GLIBC_VER}.apk \
    && curl -LfsS ${ALPINE_GLIBC_REPO}/${GLIBC_VER}/glibc-bin-${GLIBC_VER}.apk > /tmp/glibc-bin-${GLIBC_VER}.apk \
    && apk add /tmp/glibc-bin-${GLIBC_VER}.apk \
    && curl -Ls ${ALPINE_GLIBC_REPO}/${GLIBC_VER}/glibc-i18n-${GLIBC_VER}.apk > /tmp/glibc-i18n-${GLIBC_VER}.apk \
    && apk add /tmp/glibc-i18n-${GLIBC_VER}.apk \
    && /usr/glibc-compat/bin/localedef --force --inputfile POSIX --charmap UTF-8 "$LANG" || true \
    && echo "export LANG=$LANG" > /etc/profile.d/locale.sh \
    && curl -LfsS ${GCC_LIBS_URL} -o /tmp/gcc-libs.tar.xz \
    && echo "${GCC_LIBS_SHA256} */tmp/gcc-libs.tar.xz" | sha256sum -c - \
    && mkdir /tmp/gcc \
    && tar -xf /tmp/gcc-libs.tar.xz -C /tmp/gcc \
    && mv /tmp/gcc/usr/lib/libgcc* /tmp/gcc/usr/lib/libstdc++* /usr/glibc-compat/lib \
    && strip /usr/glibc-compat/lib/libgcc_s.so.* /usr/glibc-compat/lib/libstdc++.so* \
    && curl -LfsS ${ZLIB_URL} -o /tmp/libz.tar.xz \
    && echo "${ZLIB_SHA256} */tmp/libz.tar.xz" | sha256sum -c - \
    && mkdir /tmp/libz \
    && tar -xf /tmp/libz.tar.xz -C /tmp/libz \
    && mv /tmp/libz/usr/lib/libz.so* /usr/glibc-compat/lib \
    && apk del --purge .build-deps glibc-i18n \
    && rm -rf /tmp/*.apk /tmp/gcc /tmp/gcc-libs.tar.xz /tmp/libz /tmp/libz.tar.xz /var/cache/apk/*

ENV JAVA_HOME=/opt/java-minimal
ENV PATH="$PATH:$JAVA_HOME/bin"

COPY --from=packager "$JAVA_HOME" "$JAVA_HOME"
COPY build/libs/application.jar app.jar

ENTRYPOINT ["java","-jar","/app.jar"]

还读了https://blog.gilliard.lol/2018/11/05/alpine-jdk11-images.html

Answer 3

jdk 11图像按大小分列列表

openjdk:11.0.6-jre-buster
openjdk:11.0.6-jre
openjdk:11.0.6-jre-slim-buster
openjdk:11.0.6-jre-slim
openjdk:11.0.6-jre-stretch
adoptopenjdk:11.0.6_10-jre-openj9-0.18.1
adoptopenjdk:11.0.6_10-jre-hotspot
adoptopenjdk:11.0.6_10-jre-openj9-0.18.1-bionic
adoptopenjdk:11.0.6_10-jre-hotspot-bionic
adoptopenjdk/openjdk11:jre-11.0.6_10-ubuntu
adoptopenjdk/openjdk11:jre-11.0.6_10
adoptopenjdk/openjdk11:jre-11.0.6_10-ubi-minimal
adoptopenjdk/openjdk11:jre-11.0.6_10-ubi
adoptopenjdk/openjdk11:jre-11.0.6_10-debianslim
adoptopenjdk/openjdk11:jre-11.0.6_10-debian
adoptopenjdk/openjdk11:jre-11.0.6_10-centos
adoptopenjdk/openjdk11:jre-11.0.6_10-alpine
adoptopenjdk/openjdk11:x86_64-alpine-jre-11.0.6_10
adoptopenjdk/openjdk11:x86_64-debian-jre-11.0.6_10
adoptopenjdk/openjdk11:x86_64-debianslim-jre-11.0.6_10
adoptopenjdk/openjdk11:x86_64-ubi-jre-11.0.6_10
adoptopenjdk/openjdk11:x86_64-ubi-minimal-jre-11.0.6_10
adoptopenjdk/openjdk11:x86_64-centos-jre-11.0.6_10
adoptopenjdk/openjdk11:x86_64-ubuntu-jre-11.0.6_10
mcr.microsoft.com/java/jre:11u6-zulu-alpine
mcr.microsoft.com/java/jre:11u6-zulu-centos
mcr.microsoft.com/java/jre:11u6-zulu-debian8
mcr.microsoft.com/java/jre:11u6-zulu-debian9
mcr.microsoft.com/java/jre:11u6-zulu-debian10
mcr.microsoft.com/java/jre:11u6-zulu-ubuntu
azul/zulu-openjdk-alpine:11.0.6-jre

​

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