Add image labels

Dockerfile

@@ -11,3 +11,14 @@ RUN wget https://raw.githubusercontent.com/aquasecurity/kube-bench/master/cfg/co
 WORKDIR /
 ADD entrypoint.sh /entrypoint.sh
 ENTRYPOINT /entrypoint.sh
+
+# Build-time metadata as defined at http://label-schema.org
+ARG BUILD_DATE
+ARG VCS_REF
+LABEL org.label-schema.build-date=$BUILD_DATE \
+    org.label-schema.name="kube-bench" \
+    org.label-schema.description="Run the CIS Kubernetes Benchmark tests" \
+    org.label-schema.url="https://github.com/aquasecurity/kube-bench" \
+    org.label-schema.vcs-ref=$VCS_REF \
+    org.label-schema.vcs-url="https://github.com/aquasecurity/kube-bench" \
+    org.label-schema.schema-version="1.0"