Merge pull request #28 from smoe/patch-1

Patch 1 - install instructions

README.md

@@ -1 +1,53 @@
-See mkmap.sh for now :)
+# Data for Freifunk Map, Graph and Node List
+
+ffmap-backend gathers information on the batman network by invoking 
+   batctl
+and
+   batadv-vis
+as root (via sudo) and has this information placed into a target directory
+as the file "nodes.json" and also updates the directory "nodes" with graphical
+representations of uptimes and the number of clients connecting.
+
+The target directory is suggested to host all information for interpreting those
+node descriptions, e.g. as provided by https://github.com/ffnord/ffmap-d3.git .
+When executed without root privileges, we suggest to grant sudo permissions
+within wrappers of those binaries, so no further changes are required in other
+scripts:
+
+<pre>
+$ cat <<EOCAT > $HOME/batctl
+#!/bin/sh
+exec sudo /usr/sbin/batctl $*
+EOCAT
+</pre>
+
+and analogously for batadv-vis. The entry for /etc/sudoers could be
+whateveruser   ALL=(ALL:ALL) NOPASSWD: /usr/sbin/batctl,/usr/sbin/batadv-vis,/usr/sbin/alfred-json
+
+The destination directory can be made directly available through apache:
+<pre>
+$ cat /etc/apache2/site-enabled/000-default
+...
+        <Directory /home/whateverusername/www/>
+                Options Indexes FollowSymLinks MultiViews
+                AllowOverride None
+                Order allow,deny
+                allow from all
+        </Directory>
+...
+
+$ cat /etc/apache2/conf.d/freifunk
+Alias /map /home/ffmap/www/
+Alias /firmware /home/freifunk/autoupdates/
+</pre>
+
+To execute, run 
+ ./mkmap.sh ../www
+The script expects above described sudo-wrappers in the $HOME directory of the user executing
+the script. If those are not available, an error will occurr if not executed as root. Also,
+the tool realpath optionally allows to execute the script from anywhere in the directory tree.
+
+For the script's regular execution add the following to the crontab:
+<pre>
+*/5 * * * * /home/ffmap/ffmap-backend/mkmap.sh /home/ffmap/www
+</pre>