remove alpine dockerfile;base image is paketo jammy run static

Signed-off-by: Rui Yang <[email protected]>

dockerfiles/ubuntu/Dockerfile → Dockerfile

@@ -1,6 +1,8 @@
 ARG base_image=ubuntu:latest
 ARG builder_image=concourse/golang-builder
 
+FROM busybox:uclibc as busybox
+
 FROM ${builder_image} AS builder
 WORKDIR /concourse/time-resource
 COPY go.mod .
@@ -16,10 +18,10 @@ RUN set -e; for pkg in $(go list ./...); do \
 	done
 
 FROM ${base_image} AS resource
-RUN apt update && apt upgrade -y -o Dpkg::Options::="--force-confdef"
-RUN apt update && apt install -y --no-install-recommends tzdata \
-	&& rm -rf /var/lib/apt/lists/*
+USER root
 COPY --from=builder /assets /opt/resource
+COPY --from=busybox /bin/sh /bin/sh
+COPY --from=busybox /bin/cp /bin/cp
 
 FROM resource AS tests
 COPY --from=builder /tests /tests

README.md

@@ -203,11 +203,10 @@ environment is consistent across any `docker` enabled platform. When the docker
 image builds, the test are run inside the docker container, on failure they
 will stop the build.
 
-Run the tests with the following commands for both `alpine` and `ubuntu` images:
+Run the tests with the following command:
 
 ```sh
-docker build -t time-resource --target tests -f dockerfiles/alpine/Dockerfile .
-docker build -t time-resource --target tests -f dockerfiles/ubuntu/Dockerfile .
+docker build -t time-resource --target tests --build-arg base_image=paketobuildpacks/run-jammy-static:latest .
 ```
 
 ### Contributing