use lock when rsyncing benchmarking data (#904)

Fixes: #896

setup/www/resources/scripts/sync-benchmarking.sh

@@ -0,0 +1,21 @@
+#!/bin/bash
+
+pidfile=/var/run/nodejs/sync-benchmarking.pid
+cmd="
+  rsync -aqz --delete benchmark:charts/ /home/www/benchmarking/charts/ &&
+  rsync -aqz --delete benchmark:coverage-out/out/ /home/www/coverage/
+"
+
+if [ -a "$pidfile" -a -r "$pidfile" ]; then
+  read pid < "$pidfile"
+  if [ -n "${pid:-}" ]; then
+    if $(kill -0 "${pid:-}" 2> /dev/null); then
+      exit 0 # already running
+    # else stale pid
+    fi
+  fi
+fi
+
+echo $$ > $pidfile
+bash -c "$cmd"
+rm $pidfile

setup/www/tasks/site-setup.yaml

@@ -70,6 +70,15 @@
     group: root
   tags: setup
 
+- name: Site Setup | Copy sync-benchmarking.sh script
+  copy:
+    src: ./resources/scripts/sync-benchmarking.sh
+    dest: /home/nodejs/sync-benchmarking.sh
+    mode: 0755
+    owner: root
+    group: root
+  tags: setup
+
 - name: Site Setup | Make /home/nodejs/.npm
   file:
     path: /home/nodejs/.npm
@@ -78,6 +87,14 @@
     owner: nodejs
   tags: setup
 
+- name: Site Setup | Make /var/run/nodejs
+  file:
+    path: /var/run/nodejs
+    state: directory
+    mode: 0755
+    owner: nodejs
+  tags: setup
+
 - name: Site Setup | Initial nodejs, iojs and benchmarking clone and update
   become: yes
   become_user: "nodejs"
@@ -98,6 +115,5 @@
     - '*  *    * * *   nodejs  /home/nodejs/check-build-site.sh nodejs'
     - '*  *    * * *   nodejs  /home/nodejs/check-build-site.sh iojs'
     - '*  *    * * *   root    /home/nodejs/cdn-purge.sh'
-    - '* */4   * * *   nodejs  rsync -aqz --delete benchmark:charts/ /home/www/benchmarking/charts/'
-    - '* */4   * * *   nodejs  rsync -aqz --delete benchmark:coverage-out/out/ /home/www/coverage/'
+    - '* */4   * * *   nodejs  /home/nodejs/sync-benchmarking.sh'
   tags: setup