Fix seek error thrown when creating read stream in Node 8

Early Node 8 versions have a bug that force a seek upon creation of a read stream. The workaround is to pass the file descriptor directly. See: nodejs/node#19240

Change-Type: patch

Dockerfile.node8.test

@@ -0,0 +1,29 @@
+FROM resin/intel-nuc-node:8
+
+VOLUME /var/lib/docker
+
+RUN apt-get update \
+	&& apt-get install -y aufs-tools rsync iptables \
+	&& rm -rf /var/lib/apt/lists/*
+
+ENV DOCKER_VERSION 1.11.2
+RUN wget -q -O /tmp/docker-${DOCKER_VERSION}.tgz https://get.docker.com/builds/Linux/x86_64/docker-${DOCKER_VERSION}.tgz \
+	&& tar xvfz /tmp/docker-${DOCKER_VERSION}.tgz -C /tmp \
+	&& cp -r /tmp/docker/* /usr/bin/ \
+	&& rm -rf /tmp/docker \
+	&& chmod +x /usr/bin/docker*
+
+WORKDIR /usr/src/app
+
+COPY package.json /usr/src/app/
+
+RUN npm install --unsafe-perm  && npm cache clean
+
+COPY . /usr/src/app
+
+COPY test/services/ /etc/systemd/system/
+
+ENV INITSYSTEM on
+
+RUN systemctl enable docker
+CMD docker info

lib/rsync.coffee

@@ -43,4 +43,12 @@ exports.createRsyncStream = (src, dest) ->
 			ps.stderr.pipe(process.stderr)
 			ps.stdout.pipe(process.stdout)
 
-			resolve(fs.createReadStream(pipePath).on('close', cleanup))
+			# Early Node 8 versions have a bug that force a seek upon creation of
+			# a read stream. The workaround is to pass the file descriptor directly.
+			# See: https://github.com/nodejs/node/issues/19240
+			fs.open pipePath, 'r', (err, fd) ->
+				if err
+					cleanup()
+					reject(err)
+				else
+					resolve(fs.createReadStream(undefined, fd: fd).on('close', cleanup))

test.sh

@@ -7,7 +7,12 @@ function cleanup() {
 }
 trap cleanup EXIT
 
-docker build -f Dockerfile.test -t localhost/docker-delta-test .
+docker build -f Dockerfile.node6.test -t localhost/docker-delta-node6-test .
+docker run --privileged --name deltatest -d localhost/docker-delta-node6-test
+docker exec deltatest bash -c "npm run lint && ./node_modules/.bin/mocha --compilers coffee:coffee-script/register"
+
 cleanup
-docker run --privileged --name deltatest -d localhost/docker-delta-test
+
+docker build -f Dockerfile.node8.test -t localhost/docker-delta-node8-test .
+docker run --privileged --name deltatest -d localhost/docker-delta-node8-test
 docker exec deltatest bash -c "npm run lint && ./node_modules/.bin/mocha --compilers coffee:coffee-script/register"