chore(dockerfile): various Dockerfile cleanups (#4795)

* chore(dockerfile): delete the (unused) java8 dockerfiles

* chore(dockerfile): replace deprecated MAINTAINER with LABEL

* chore(dockerfile): use gid/uid 10111 for the spinnaker user

* chore(dockerfile): make docker builds more cacheable

Dockerfile.compile

@@ -3,7 +3,7 @@ RUN apt-get update && apt-get install -y \
     openjdk-8-jdk \
     openjdk-11-jdk \
  && rm -rf /var/lib/apt/lists/*
-MAINTAINER sig-platform@spinnaker.io
+LABEL maintainer="sig-platform@spinnaker.io"
 ENV JAVA_HOME /usr/lib/jvm/java-11-openjdk-amd64
 ENV JDK_18 /usr/lib/jvm/java-8-openjdk-amd64
 ENV GRADLE_USER_HOME /workspace/.gradle

Dockerfile.slim

@@ -1,6 +1,5 @@
 FROM alpine:3.11
-MAINTAINER sig-platform@spinnaker.io
-COPY clouddriver-web/build/install/clouddriver /opt/clouddriver
+LABEL maintainer="sig-platform@spinnaker.io"
 
 ENV KUBECTL_VERSION v1.17.6
 
@@ -29,8 +28,10 @@ ENV PATH "$PATH:/usr/local/bin/"
 
 ENV PATH=$PATH:/opt/google-cloud-sdk/bin/
 
-RUN adduser -D -S spinnaker
+RUN addgroup -S -g 10111 spinnaker
+RUN adduser -S -G spinnaker -u 10111 spinnaker
 
+COPY clouddriver-web/build/install/clouddriver /opt/clouddriver
 RUN mkdir -p /opt/clouddriver/plugins && chown -R spinnaker:nogroup /opt/clouddriver/plugins
 
 USER spinnaker

Dockerfile.ubuntu

@@ -1,6 +1,5 @@
 FROM ubuntu:bionic
-MAINTAINER sig-platform@spinnaker.io
-COPY clouddriver-web/build/install/clouddriver /opt/clouddriver
+LABEL maintainer="sig-platform@spinnaker.io"
 
 RUN apt-get update && apt-get install -y curl gnupg && \
   curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add - && \
@@ -22,7 +21,8 @@ RUN curl -o  /usr/local/bin/aws-iam-authenticator https://amazon-eks.s3.us-west-
   chmod +x /usr/local/bin/aws-iam-authenticator && \
   ln -s    /usr/local/bin/aws-iam-authenticator /usr/local/bin/heptio-authenticator-aws
 
-RUN adduser --disabled-login --system spinnaker
+RUN adduser --system --uid 10111 --group spinnaker
+COPY clouddriver-web/build/install/clouddriver /opt/clouddriver
 RUN mkdir -p /opt/clouddriver/plugins && chown -R spinnaker:nogroup /opt/clouddriver/plugins
 USER spinnaker
 CMD ["/opt/clouddriver/bin/clouddriver"]