lightweight pubsub emulator image

Dockerfile

FROM alpine@sha256:ddba4d27a7ffc3f86dd6c2f92041af252a1f23a8e742c90e6e1297bfa1bc0c45 AS build
RUN apk add --no-cache ca-certificates curl python3
ARG CLOUD_SDK_VERSION=280.0.0
RUN curl https://dl.google.com/dl/cloudsdk/channels/rapid/downloads/google-cloud-sdk-${CLOUD_SDK_VERSION}-linux-x86_64.tar.gz \
      | tar xzf -

RUN /google-cloud-sdk/install.sh \
      --bash-completion=false \
      --override-components beta pubsub-emulator \
      --path-update=false \
      --usage-reporting=false

FROM adoptopenjdk/openjdk11:x86_64-alpine-jre-11.0.6_10@sha256:6976e4105fbd639fc2f61ac974578209587d7f0e29607065661c5aaf92649242
RUN apk add --no-cache tini
COPY --from=build /google-cloud-sdk/platform/pubsub-emulator /pubsub-emulator
ENTRYPOINT ["/sbin/tini", "--",  "java", "-jar", "/pubsub-emulator/lib/cloud-pubsub-emulator-0.1-SNAPSHOT-all.jar"]