Support BuildArgs for arg command

integration_tests/dockerfiles/Dockerfile_test_add

@@ -14,5 +14,9 @@ ADD $contextenv/* /tmp/${contextenv}/
 ADD context/tars/fil* /tars/
 ADD context/tars/file.tar /tars_again
 
+# Test with ARG
+ARG file
+COPY $file /arg
+
 # Finally, test adding a remote URL, concurrently with a normal file
 ADD https://github.com/GoogleCloudPlatform/docker-credential-gcr/releases/download/v1.4.3/docker-credential-gcr_linux_386-1.4.3.tar.gz context/foo /test/all/

integration_tests/dockerfiles/Dockerfile_test_onbuild

@@ -1,6 +1,7 @@
 FROM gcr.io/kaniko-test/onbuild-base:latest
 COPY context/foo foo
 ENV dir /new/workdir/
-ONBUILD RUN echo "onbuild" > /tmp/onbuild
+ARG file
+ONBUILD RUN echo "onbuild" > $file
 ONBUILD RUN echo "onbuild 2" > ${dir}
 ONBUILD WORKDIR /new/workdir

integration_tests/dockerfiles/Dockerfile_test_run

@@ -17,3 +17,7 @@ RUN echo "hey" > /etc/foo
 RUN echo "baz" > /etc/baz
 RUN cp /etc/baz /etc/bar
 RUN rm /etc/baz
+
+# Test with ARG
+ARG file
+RUN echo "run" > $file

integration_tests/dockerfiles/Dockerfile_test_scratch

@@ -1,4 +1,14 @@
 FROM scratch
-ADD context/foo /foo
-ENV hello hello
-ADD context/foo /$hello
+# First, make sure simple arg replacement works
+ARG file
+COPY $file /foo
+# Check that setting a default value works
+ARG file2=context/bar/bat
+COPY $file2 /bat
+# Check that overriding a default value works
+ARG file3=context/bar/baz
+COPY $file3 /baz
+# Check that setting an ENV will override the ARG
+ENV file context/bar/bam/bat
+COPY $file /env 
+

integration_tests/dockerfiles/Dockerfile_test_workdir

@@ -11,3 +11,7 @@ ENV dir /another/new/dir
 WORKDIR $dir/newdir
 WORKDIR $dir/$doesntexist
 WORKDIR /
+
+# Test with ARG
+ARG workdir
+WORKDIR $workdir