Hey I was wondering how to setup docker build with...

# ktor

[Tech]

Hey I was wondering how to setup docker build with github actions just to see if my code actually compiles.
It currently errors out with this When using COPY with more than one source file, the destination must be a directory and end with a / however if I add a / to the end of the copy statement it stops building locally.

Here's the Dockerfile

FROM gradle as build
COPY --chown=gradle:gradle . /home/gradle/src
WORKDIR /home/gradle/src
RUN gradle buildFatJar --no-daemon

FROM openjdk:17
EXPOSE 8080:8080

RUN mkdir /app
COPY --from=build /home/gradle/src/build/libs/*.jar /app/ktor-app.jar
ENTRYPOINT ["java", "-jar", "/app/ktor-app.jar"]

[Trevor Stone]

Not sure if this wouldn't work for you, but there is https://ktor.io/docs/docker.html

This uses a plugin which delegates to jib https://github.com/GoogleContainerTools/jib to build your container instead of using a Dockerfile. This adds gradle tasks to build and run the container

[CLOVIS]

Alternatively, this is a Dockerfile that works: https://gitlab.com/opensavvy/formulaide/-/blob/main/.gitlab/backend.dockerfile

Just run ./gradlew assembleDist before building it

[Tech]

Does it work with GitHub actions? That’s the main problem I’m experiencing at the moment

[CLOVIS]

It's just a Dockerfile, it runs in whatever runs a Dockerfile

[Tech]

With the error message I stated above that only occurs with GitHub actions however locally it’s fine, it’s weird

[CLOVIS]

Old version of Docker in one of the two envs?

[Tech]

Perhaps, let me quickly check my local docker version

[Tech]

I'm running 20.10.17

[Trevor Stone]

using the ktor jib plugin builds without issue on github actions for me

[Trevor Stone]

also do you know which copy isn't working?

[Trevor Stone]

COPY --from=build /home/gradle/src/build/libs/*.jar /app/ktor-app.jar
This seems like it could be the problem due to that wildcard

[Tech]

Yeah that's the copy that isn't working, do you by chance have a solution to that or just recommend me to use jib?

[Tech]

I don't have much experience with Docker/CD stuff so I'd prefer to stay away from things such as jib since I don't really understand it at the moment 😅

[Trevor Stone]

using the ktor docker plugin would most likely be easiest tbh unless you really want to learn dockerfiles

[Trevor Stone]

https://github.com/GoogleContainerTools/jib/blob/master/docs/faq.md#what-would-a-dockerfile-for-a-jib-built-image-look-like

[Trevor Stone]

This is a dockerfile that outputs similar to jib

[Trevor Stone]

this could probably guide you to fixing your problem though

[Tech]

Interesting, I'll try it out thank you so much.