IntelliJ Ktor and Docker is there a better way? - intellij-idea

Question

So I started a ktor project in IntelliJ it runs fine there. However, I am attempting to now have docker use the jar created from the build/libs directory and I get this error:
WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
Error: A JNI error has occurred, please check your installation and try again
Exception in thread "main" java.lang.NoClassDefFoundError: io/ktor/application/Application
at java.lang.Class.getDeclaredMethods0(Native Method)
at java.lang.Class.privateGetDeclaredMethods(Class.java:2701)
at java.lang.Class.privateGetMethodRecursive(Class.java:3048)
at java.lang.Class.getMethod0(Class.java:3018)
at java.lang.Class.getMethod(Class.java:1784)
at sun.launcher.LauncherHelper.validateMainClass(LauncherHelper.java:544)
at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:526)
Caused by: java.lang.ClassNotFoundException: io.ktor.application.Application
at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 7 more
This is what my ktor.Dockerfile looks like:
FROM openjdk:8-jre-alpine
ENV APPLICATION_USER ktor
RUN adduser -D -g '' $APPLICATION_USER
RUN mkdir /app
RUN chown -R $APPLICATION_USER /app
USER $APPLICATION_USER
COPY ./build/libs/website-0.0.1.jar /app/website-0.0.1.jar
WORKDIR /app
CMD ["java", "-server", "-XX:+UnlockExperimentalVMOptions", "-XX:+UseCGroupMemoryLimitForHeap", "-XX:InitialRAMFraction=2", "-XX:MinRAMFraction=2", "-XX:MaxRAMFraction=2", "-XX:+UseG1GC", "-XX:MaxGCPauseMillis=100", "-XX:+UseStringDeduplication", "-cp", "website-0.0.1.jar", "com.diracian.ApplicationKt"]
What I did first was start a ktor project, and after I got that working, I started working on my Dockerfile.

Answer 1

Actually, ended up breaking it up in pieces.
My file looks like this now and works:
FROM gradle:jdk10 as builder
COPY --chown=gradle:gradle . /home/gradle/src
WORKDIR /home/gradle/src
RUN gradle build
FROM openjdk:10-jre-slim
EXPOSE 8080
COPY --from=builder /home/gradle/src/build/distributions/website-0.0.1.tar /app/
WORKDIR /app
RUN tar -xvf website-0.0.1.tar
WORKDIR /app/website-0.0.1
CMD bin/website