在docker映像中安装docker上的Java

Question

我想在docker image中的docker上安装openjdk。当我尝试执行此操作时，收到以下错误消息：

​

fetch http://dl-cdn.alpinelinux.org/alpine/v3.5/main/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/v3.5/community
ERROR: unsatisfiable constraints:
  openjdk8-8.121.13-r0:
    breaks: world[openjdk8=8.111.14-r0]
The command '/bin/sh -c set -x  && apk add --no-cache       openjdk8="$JAVA_ALPINE_VERSION" && [ "$JAVA_HOME" = "$(docker-java-home)" ]' returned a non-zero code: 1

​

我的Dockerfile当前如下所示：

FROM docker:latest
RUN apk update
ENV LANG C.UTF-8
RUN { \
        echo '#!/bin/sh'; \
        echo 'set -e'; \
        echo; \
        echo 'dirname "$(dirname "$(readlink -f "$(which javac || which java)")")"'; \
    } > /usr/local/bin/docker-java-home \
    && chmod +x /usr/local/bin/docker-java-home
ENV JAVA_HOME /usr/lib/jvm/java-1.8-openjdk
ENV PATH $PATH:/usr/lib/jvm/java-1.8-openjdk/jre/bin:/usr/lib/jvm/java-1.8-openjdk/bin
ENV JAVA_VERSION 8u111
ENV JAVA_ALPINE_VERSION 8.111.14-r0
RUN set -x \
    && apk add --no-cache \
        openjdk8="$JAVA_ALPINE_VERSION" \
&& [ "$JAVA_HOME" = "$(docker-java-home)" ]

​

Answer 1

有一个关于官方Java镜像如何在高山镜像上烘焙的Dockerfile参考：https://github.com/docker-library/openjdk/blob/9a0822673dffd3e5ba66f18a8547aa60faed6d08/8-jdk/alpine/Dockerfile

或者你可以换一种方式来做，

# build ontop of official Java image
FROM java:openjdk-8-jdk-alpine

RUN apk update && \
    apk add docker
...

Answer 2

正如@user2105103提到的，这是JDK版本的问题。

你可以简单地跳过这个版本，问题就会消失。示例：

FROM docker:latest

# Default to UTF-8 file.encoding
ENV LANG C.UTF-8

# add a simple script that can auto-detect the appropriate JAVA_HOME value
# based on whether the JDK or only the JRE is installed
RUN { \
        echo '#!/bin/sh'; \
        echo 'set -e'; \
        echo; \
        echo 'dirname "$(dirname "$(readlink -f "$(which javac || which java)")")"'; \
    } > /usr/local/bin/docker-java-home \
    && chmod +x /usr/local/bin/docker-java-home

ENV JAVA_HOME /usr/lib/jvm/java-1.8-openjdk
ENV PATH $PATH:/usr/lib/jvm/java-1.8-openjdk/jre/bin:/usr/lib/jvm/java-1.8-openjdk/bin

ENV JAVA_VERSION 8u111
ENV JAVA_ALPINE_VERSION 8.111.14-r0

RUN set -x && apk add --no-cache openjdk8 && [ "$JAVA_HOME" = "$(docker-java-home)" ]

在这种情况下，您将获得最新的JDK版本。希望能有所帮助。