Update armhf to use armv6 binaries

sample-functions/MarkdownRender/Dockerfile.armhf

@@ -0,0 +1,15 @@
+FROM armhf/alpine:3.5
+
+ADD https://github.com/alexellis/faas/releases/download/v0.3-alpha/fwatchdog-armhf /usr/bin/fwatchdog
+RUN chmod +x /usr/bin/fwatchdog
+
+WORKDIR /root/
+
+EXPOSE 8080
+ENV http_proxy      ""
+ENV https_proxy     ""
+
+COPY app    .
+
+ENV fprocess="/root/app"
+CMD ["fwatchdog"]

sample-functions/MarkdownRender/Dockerfile.build.armhf

@@ -0,0 +1,11 @@
+FROM alexellis2/alexellis2/go-armhf:1.7.4
+
+RUN mkdir -p /go/src/app
+COPY handler.go /go/src/app
+WORKDIR /go/src/app
+RUN go get github.com/microcosm-cc/bluemonday && \
+    go get github.com/russross/blackfriday
+
+RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o app .
+
+CMD ["echo"]

sample-functions/MarkdownRender/build.armhf.sh

@@ -0,0 +1,14 @@
+#!/bin/sh
+echo Building alexellis2/faas-markdownrender:build-armhf
+
+docker build --build-arg https_proxy=$https_proxy --build-arg http_proxy=$http_proxy \
+    -t alexellis2/faas-markdownrender:build-armhf \
+    . -f Dockerfile.build.armhf
+
+docker create --name render_extract alexellis2/faas-markdownrender:build-armhf
+docker cp render_extract:/go/src/app/app ./app
+docker rm -f render_extract
+
+echo Building alexellis2/faas-markdownrender:latest-armhf
+docker build --no-cache -t alexellis2/faas-markdownrender:latest-armhf .\
+       -f Dockerfile.armhf