Testing Swing elements in a Headless Environment (gitlab CI)

Question

I have a gradle project using gitlab's CI, unforunately using any Swing classes results in:
java.awt.AWTException: headless environment

I found one answer at Easiest way to unit test SWT and Swing apps in a headless environment? that mentioned using Xvfb, which seems like it would work, but didn't elaborate because there was a tool-specific simpler option. If Xvfb would work, how does it need to be configured in my project? I couldn't find any resources for gitlab/gradle. Is there a simpler option specific to gitlab?

Answer 1

So I was able to find a solution that has just worked. I ended up creating my own Docker image:

FROM alpine:3.10
RUN apk update
RUN apk --no-cache add openjdk11 --repository=http://dl-cdn.alpinelinux.org/alpine/edge/community
RUN apk add xvfb-run

and then I just had to update my .gitlab-ci.yml to use that image:

image: jeffreydm/xvfb-java:v0.1

and lastly, I updated my script from:

build:
  stage: build
  script:
    - ./gradlew build

to:

build:
  stage: build
  script:
    - xvfb-run ./gradlew build