Fix builds on ARM arch but keeping ARM cross builds. Fix #638.

proxy/Dockerfile.armhf

@@ -1,7 +1,5 @@
 FROM resin/rpi-raspbian:stretch
 
-RUN [ "cross-build-start" ]
-
 RUN apt-get update \
       && apt-get install -y \
         ca-certificates \
@@ -16,5 +14,3 @@ EXPOSE 8080
 COPY nginx.conf /etc/nginx/nginx.conf
 
 CMD ["nginx", "-g", "daemon off;"]
-
-RUN [ "cross-build-end" ]

proxy/DockerfileCrossBuild.armhf

@@ -0,0 +1,22 @@
+# This Dockerfile is for building ARM images on x64 machine like Docker Hub
+
+FROM resin/rpi-raspbian:stretch
+
+RUN [ "cross-build-start" ]
+
+RUN apt-get update \
+      && apt-get install -y \
+        ca-certificates \
+        nginx \
+      && rm -rf /var/lib/apt/lists/*
+
+RUN ln -sf /dev/stdout /var/log/nginx/access.log \
+      && ln -sf /dev/stderr /var/log/nginx/error.log
+
+EXPOSE 8080
+
+COPY nginx.conf /etc/nginx/nginx.conf
+
+CMD ["nginx", "-g", "daemon off;"]
+
+RUN [ "cross-build-end" ]