Run Go build as current user via -u flag

Remove complicated workaround in build.sh

Makefile

@@ -91,6 +91,7 @@ $(SCOPE_EXE) $(RUNSVINIT) lint tests shell prog/staticui/staticui.go prog/extern
 	$(SUDO) docker run $(RM) $(RUN_FLAGS) \
 		-v $(shell pwd):/go/src/github.com/weaveworks/scope \
 		-v $(shell pwd)/.pkg:/go/pkg \
+		-u $(shell id -u ${USER}):$(shell id -g ${USER}) \
 		--net=host \
 		-e GOARCH -e GOOS -e CIRCLECI -e CIRCLE_BUILD_NUM -e CIRCLE_NODE_TOTAL \
 		-e CIRCLE_NODE_INDEX -e COVERDIR -e SLOW -e TESTDIRS \

backend/build.sh

@@ -7,14 +7,4 @@ SCOPE_SRC=$GOPATH/src/github.com/weaveworks/scope
 # Mount the scope repo:
 #  -v $(pwd):/go/src/github.com/weaveworks/scope
 
-# If we run make directly, any files created on the bind mount
-# will have awkward ownership.  So we switch to a user with the
-# same user and group IDs as source directory.  We have to set a
-# few things up so that sudo works without complaining later on.
-uid=$(stat --format="%u" "$SCOPE_SRC")
-gid=$(stat --format="%g" "$SCOPE_SRC")
-echo "weave:x:$uid:$gid::$SCOPE_SRC:/bin/sh" >>/etc/passwd
-echo "weave:*:::::::" >>/etc/shadow
-echo "weave	ALL=(ALL)	NOPASSWD: ALL" >>/etc/sudoers
-
-su weave -c "PATH=$PATH make -C $SCOPE_SRC BUILD_IN_CONTAINER=false $*"
+make -C $SCOPE_SRC BUILD_IN_CONTAINER=false $*