Change from JRE to JDK in Docker container

Question

I am using tomcat, jre 8(openjdk),alpine linux as base image. My Dockerfile is follow:

FROM tomcat:8.5.39-jre8-alpine

RUN rm -rf /usr/local/tomcat/webapps/*

COPY target/openjdk8-8.252.09-r0.apk /usr/local/tomcat/.

RUN apk add --allow-untrusted /usr/local/tomcat/openjdk8-8.252.09-r0.apk

ENV JAVA_HOME=/usr/lib/jvm/java-1.8-openjdk

ENV PATH=/usr/local/tomcat/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/lib/jvm/java-1.8-openjdk/bin

RUN export JAVA_HOME

RUN export PATH

I want to use jdk8 instead of jre8.
In order to do that, I have downloaded same version of JDK8 and install it on alpine linux.

COPY target/openjdk8-8.252.09-r0.apk /usr/local/tomcat/.
RUN apk add --allow-untrusted /usr/local/tomcat/openjdk8-8.252.09-r0.apk

And to make sure desired java(JDK8) is picked up, I set JAVA_HOME and PATH.

ENV JAVA_HOME=/usr/lib/jvm/java-1.8-openjdk
ENV PATH=/usr/local/tomcat/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/lib/jvm/java-1.8-openjdk/bin

But still when I run Tomcat(when I run container), /usr/lib/jvm/java-1.8-openjdk/jre is logged in console meaning that original JRE is still in use.

I have read this one. But I do not understand clearly what he means by it.

Is there any workaround or any way to get it working? Or where did I make mistake?

Cheers

Just out of curiosity: Why do you want to use the JDK instead of the JRE? — Turing85, Aug 12 '20 at 16:27
You said you wanted to use tools from the JDK. Did you confirm the tools are not there after installing the JDK? — Andy Shinn, Aug 13 '20 at 01:33

score 1 · Answer 1 · answered Aug 13 '20 at 02:13

I am using OpenJDK8 with Alpine in Docker image with a following Docker:

FROM alpine:3.11.3
ENV LANG=C.UTF-8 \
      JAVA_HOME=/usr/lib/jvm/java-1.8-openjdk \
      PATH=$PATH:/usr/lib/jvm/java-1.8-openjdk/bin/

RUN  set -x apk add --no-cache openjdk8

Change from JRE to JDK in Docker container

1 Answers1