RHDEVDOCS-3033 Link from build docs to understand-how-arg-and-from-interact topic

Author: rolfedh

modules/builds-strategy-docker-build-arguments.adoc

@@ -6,6 +6,11 @@
 
 You can set link:http://docs.docker.com/v1.7/reference/api/hub_registry_spec/#docker-registry-1-0[docker build arguments] using the `BuildArgs` array. The build arguments are passed to docker when a build is started.
 
+[TIP]
+====
+See link:https://docs.docker.com/engine/reference/builder/#understand-how-arg-and-from-interact[Understand how ARG and FROM interact] in the Dockerfile reference documentation.
+====
+
 .Procedure
 
 To set docker build arguments, add entries to the `BuildArgs` array, which is located in the `dockerStrategy` definition of the `BuildConfig` object. For example:
@@ -18,3 +23,8 @@ dockerStrategy:
     - name: "foo"
       value: "bar"
 ----
+
+[NOTE]
+====
+Only the `name` and `value` fields are supported. Any settings on the `valueFrom` field are ignored.
+====

modules/builds-strategy-docker-build.adoc

@@ -6,4 +6,9 @@
 [id="builds-strategy-docker-build_{context}"]
 = Docker build
 
-The docker build strategy invokes the docker build command, and it expects a repository with a Dockerfile and all required artifacts in it to produce a runnable image.
+{product-title} uses Buildah to build a container image from a Dockerfile. For more information on building container images with Dockerfiles, see link:https://docs.docker.com/engine/reference/builder/[the Dockerfile reference documentation].
+
+[TIP]
+====
+If you work with build arguments, see link:https://docs.docker.com/engine/reference/builder/#understand-how-arg-and-from-interact[Understand how ARG and FROM interact] in the Dockerfile reference documentation.
+====