feat(build): Ubuntu image variant support (#417)

* feat(build): Building a ubuntu image

* New tagging format: `version-variant`, example: `1.2.3-slim`
* For backward compatibility with the buildtool system and older versions of Halyard, the alpine image variant keeps the original 'naked' version tag i.e. `1.2.3` in addition to the one with the new format.
* The BOM format doesn't change, it's up to Halyard to append the right `-variant` for a tag to fetch the right image on the registry.
* The Dockerfiles are meant to be used directly for ad-hoc image creation by an end-user and by the existing build system through `cloudbuild.yml`.

* Cloudbuild.yaml is now generic and lives in spinnaker/spinnaker buildtool

Dockerfile.compile

@@ -0,0 +1,6 @@
+FROM gcr.io/spinnaker-marketplace/gradle_cache
+MAINTAINER delivery-engineering@netflix.com
+ENV GRADLE_USER_HOME /gradle_cache/.gradle
+COPY . compiled_sources
+WORKDIR compiled_sources
+RUN ./gradlew --no-daemon rosco-web:installDist -x test

Dockerfile.slim

@@ -1,10 +1,8 @@
 FROM openjdk:8-jre-alpine
-
 MAINTAINER delivery-engineering@netflix.com
-
-COPY ./rosco-web/build/install/rosco /opt/rosco
-COPY ./rosco-web/config /opt/rosco
-COPY ./rosco-web/config/packer /opt/rosco/config/packer
+COPY --from=compile /compiled_sources/rosco-web/build/install/rosco /opt/rosco
+COPY --from=compile /compiled_sources/rosco-web/config              /opt/rosco
+COPY --from=compile /compiled_sources/rosco-web/config/packer       /opt/rosco/config/packer
 
 WORKDIR /packer
 
@@ -21,7 +19,6 @@ RUN wget https://raw.githubusercontent.com/kubernetes/helm/master/scripts/get &&
   rm get
 
 RUN adduser -D -S spinnaker
-
 USER spinnaker
-
 CMD ["/opt/rosco/bin/rosco"]
+

Dockerfile.ubuntu

@@ -0,0 +1,23 @@
+FROM ubuntu:bionic
+MAINTAINER delivery-engineering@netflix.com
+COPY --from=compile /compiled_sources/rosco-web/build/install/rosco /opt/rosco
+COPY --from=compile /compiled_sources/rosco-web/config              /opt/rosco
+COPY --from=compile /compiled_sources/rosco-web/config/packer       /opt/rosco/config/packer
+
+WORKDIR /packer
+
+RUN apt-get update && apt-get -y install openjdk-8-jre-headless wget unzip curl && \
+  wget https://releases.hashicorp.com/packer/1.4.2/packer_1.4.2_linux_amd64.zip && \
+  unzip packer_1.4.2_linux_amd64.zip && \
+  rm packer_1.4.2_linux_amd64.zip
+
+ENV PATH "/packer:$PATH"
+
+RUN wget https://raw.githubusercontent.com/kubernetes/helm/master/scripts/get && \
+  chmod +x get && \
+  ./get && \
+  rm get
+
+RUN adduser --disabled-login --system spinnaker
+USER spinnaker
+CMD ["/opt/rosco/bin/rosco"]