CICD Exercises - Update gradle.Dockerfile for Jenkins lab

Author: JTrillo

03-cd/exercises/jenkins-resources/gradle.Dockerfile

@@ -1,4 +1,4 @@
-FROM jenkins/jenkins:lts
+FROM jenkins/jenkins:lts-jdk11
 
 USER root
 
@@ -27,4 +27,4 @@ RUN mkdir -p /usr/share/gradle /usr/share/gradle/ref \
 
 ENV GRADLE_VERSION 6.6.1
 ENV GRADLE_HOME /usr/bin/gradle
-ENV PATH $PATH:$GRADLE_HOME/bin
+ENV PATH $PATH:$GRADLE_HOME/bin