standardize actionloop Dockerfile build logic (#106)

Author: dgrove-oss

core/java8actionloop/Dockerfile

@@ -14,12 +14,26 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
-FROM golang:1.12 as builder
-RUN env CGO_ENABLED=0 go get github.com/apache/openwhisk-runtime-go/main
+
+# build go proxy from source
+FROM golang:1.12 AS builder_source
+RUN env CGO_ENABLED=0 go get github.com/apache/openwhisk-runtime-go/main && mv /go/bin/main /bin/proxy
+
+# or build it from a release
+FROM golang:1.12 AS builder_release
+ARG GO_PROXY_RELEASE_VERSION=1.12@1.15.0
+RUN curl -sL \
+  https://github.com/apache/openwhisk-runtime-go/archive/{$GO_PROXY_RELEASE_VERSION}.tar.gz\
+  | tar xzf -\
+  && cd openwhisk-runtime-go-*/main\
+  && GO111MODULE=on go build -o /bin/proxy
 
 # Use AdoptOpen JDK8, OpenJ9 release version 0.15.1
 FROM adoptopenjdk/openjdk8-openj9:x86_64-ubuntu-jdk8u222-b10_openj9-0.15.1
 
+# select the builder to use
+ARG GO_PROXY_BUILD_FROM=release
+
 RUN rm -rf /var/lib/apt/lists/* && apt-get clean && apt-get update \
 	&& apt-get install -y --no-install-recommends locales python vim \
 	&& rm -rf /var/lib/apt/lists/* \
@@ -36,7 +50,10 @@ RUN locale-gen en_US.UTF-8 ;\
     mkdir -p /javaAction/action /usr/java/src /usr/java/lib
 
 WORKDIR /javaAction
-COPY --from=builder /go/bin/main /bin/proxy
+
+COPY --from=builder_source /bin/proxy /bin/proxy_source
+COPY --from=builder_release /bin/proxy /bin/proxy_release
+RUN mv /bin/proxy_${GO_PROXY_BUILD_FROM} /bin/proxy
 
 ADD https://search.maven.org/remotecontent?filepath=com/google/code/gson/gson/2.8.5/gson-2.8.5.jar /usr/java/lib/gson-2.8.5.jar
 ADD lib/src/Launcher.java /usr/java/src/Launcher.java

gradle/docker.gradle

@@ -54,7 +54,7 @@ if(project.hasProperty('dockerHost')) {
 }
 
 if(project.hasProperty('dockerBuildArgs')) {
-    dockerBuildArgs.each { arg  ->
+    dockerBuildArgs.split(' ').each { arg  ->
         dockerBuildArg += ['--build-arg', arg]
     }
 }