working around dockerhub limitations...

Dockerfile

@@ -1,5 +1,6 @@
-ARG CODE_VERSION 3.6
-FROM arm32v6/alpine:$CODE_VERSION
+# keeping duplicated Dockerfiles for now, until dockerhub upgrades to 1.9
+# ARG CODE_VERSION 3.6
+FROM arm32v6/alpine:3.6
 
 ENV QEMU_EXECVE 1
 

Dockerfile.3.5

@@ -0,0 +1,7 @@
+FROM arm32v6/alpine:3.5
+
+ENV QEMU_EXECVE 1
+
+COPY . /usr/bin
+
+RUN [ "qemu-arm-static", "/bin/sh", "-c", "ln -s resin-xbuild /usr/bin/cross-build-start; ln -s resin-xbuild /usr/bin/cross-build-end; ln /bin/sh /bin/sh.real" ]

hooks/build

@@ -2,6 +2,9 @@
 
 echo "Build hook running"
 
-docker build --build-arg CODE_VERSION=3.6 -t $DOCKER_REPO:3.6-$CACHE_TAG .
+# once dockerhub supports ARG before FROM (upgrade to 1.9)
+# docker build --build-arg CODE_VERSION=3.6 -t $DOCKER_REPO:3.6-$CACHE_TAG .
+# docker build --build-arg CODE_VERSION=3.5 -t $DOCKER_REPO:3.5-$CACHE_TAG .
 
-docker build --build-arg CODE_VERSION=3.5 -t $DOCKER_REPO:3.5-$CACHE_TAG .
+docker build -t $DOCKER_REPO:3.6-$CACHE_TAG -f Dockerfile .
+docker build -t $DOCKER_REPO:3.5-$CACHE_TAG -f Dockerfile.3.5 .