Merge pull request #2621 from weaveworks/2576-go-1.8

Use Go 1.8

backend/Dockerfile

@@ -1,11 +1,12 @@
 FROM ubuntu:yakkety
 ENV GOPATH /go
-ENV GOVERSION 1.7
-ENV PATH /go/bin:/usr/lib/go-${GOVERSION}/bin:/usr/bin:/bin:/usr/sbin:/sbin
+ENV GOVERSION 1.8
+ENV PATH /go/bin:/usr/local/go/bin:/usr/bin:/bin:/usr/sbin:/sbin
 ENV SCOPE_SKIP_UI_ASSETS true
 RUN apt-get update && \
-	apt-get install -y libpcap-dev python-requests time file shellcheck golang-${GOVERSION} git gcc-arm-linux-gnueabihf curl && \
+	apt-get install -y libpcap-dev python-requests time file shellcheck git gcc-arm-linux-gnueabihf curl build-essential && \
 	rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
+RUN curl -Ls https://storage.googleapis.com/golang/go${GOVERSION}.linux-amd64.tar.gz | tar xz -C /usr/local
 RUN go clean -i net && \
 	go install -tags netgo std && \
 	go install -race -tags netgo std
@@ -19,7 +20,7 @@ RUN go get -tags netgo \
 		github.com/fatih/hclfmt \
 		github.com/mjibson/esc \
 		github.com/client9/misspell/cmd/misspell && \
-	chmod a+wr --recursive /usr/lib/go-${GOVERSION}/pkg && \
+	chmod a+wr --recursive /usr/local/go && \
 	rm -rf /go/pkg/ /go/src/
 COPY build.sh /
 ENTRYPOINT ["/build.sh"]