Merge pull request #959 from tim-moody/mkiwix-lib

Add concurrency to iiab-make-kiwix-lib

roles/kiwix/templates/iiab-make-kiwix-lib

@@ -1,8 +1,30 @@
-#!/bin/bash
-
-{{ systemctl_program }} stop kiwix-serve
-/usr/bin/iiab-make-kiwix-lib.py
-#/usr/bin/iiab-make-apache-config.py
-{{ systemctl_program }} start kiwix-serve
-
-exit 0
+#!/bin/bash
+
+LOCK_PATH=/run/lock/kiwix
+mkdir -p $LOCK_PATH
+
+WAITLOCK="$LOCK_PATH/make-kiwix-lib-wait.LCK";
+RUNLOCK="$LOCK_PATH/kiwix-lib-access.LCK";
+KIWIXLIB={{ kiwix_library_xml }}
+
+exec 200>$WAITLOCK;
+exec 201>$RUNLOCK;
+
+if flock -n -e 200; then :
+  echo 'Waiting to run iiab-make-kiwix-lib.py'
+  # wait for up to 5 min
+  flock -x -w 300 201
+  flock -u 200 # unlock queue
+  echo "Now running iiab-make-kiwix-lib.py"
+  # write to {{ kiwix_library_xml }}.tmp to minimize kiwix down
+  # zim map could be out of sync for a few seconds
+  /usr/bin/iiab-make-kiwix-lib.py
+  {{ systemctl_program }} stop kiwix-serve
+  rm $KIWIXLIB
+  mv $KIWIXLIB.tmp $KIWIXLIB
+  {{ systemctl_program }} start kiwix-serve
+else
+  echo "Can't get wait lock for iiab-make-kiwix-lib.py";
+  exit 1;
+fi
+exit 0

roles/kiwix/templates/iiab-make-kiwix-lib.py

@@ -2,7 +2,7 @@
 
 """
 
-   Creates library.xml file for kiwix from contents of /zims/content and index
+   Creates temp library.xml file for kiwix from contents of /zims/content and index
 
    Author: Tim Moody <tim(at)timmoody(dot)com>
    Contributors: Jerry Vonau <jvonau3(at)gmail.com>
@@ -30,6 +30,8 @@ iiab_config_file = "{{ iiab_config_file }}"
 # Variables that should be read from config file
 # All of these variables will be read from config files and recomputed in init()
 iiab_zim_path = "{{ iiab_zim_path }}"
+
+# Later we will append .tmp to file name
 kiwix_library_xml = "{{ kiwix_library_xml }}"
 
 iiab_base_path = "{{ iiab_base }}"
@@ -41,8 +43,9 @@ old_zim_map = {"bad.zim" : "unparseable name"}
 
 def main():
     """Server routine"""
-
+    global kiwix_library_xml
     init()
+    kiwix_library_xml += '.tmp' # write to temp file    
 
     # remove existing file
     try: