# Data for Freifunk Map, Graph and Node List

[![Build Status](https://travis-ci.org/ffnord/ffmap-backend.svg?branch=master)](https://travis-ci.org/ffnord/ffmap-backend)

ffmap-backend gathers information on the batman network by invoking :

 * batctl (might require root),
 * alfred-json and
 * batadv-vis

In order to use alfred-json and batadv-vis make sure the user running this
backend is allowed to access alfred's socket.

The output will be written to a directory (`-d output`).

Run `backend.py --help` for a quick overview of all available options.

For the script's regular execution add the following to the crontab:

<pre>
* * * * * /path/to/ffmap-backend/backend.py -d /path/to/output -a /path/to/aliases.json --vpn ae:7f:58:7d:6c:2a --vpn d2:d0:93:63:f7:da
</pre>

# Data format

## nodes.json

    { 'nodes': {
        node_id: { 'flags': { flags },
                   'firstseen': isoformat,
                   'lastseen': isoformat,
                   'nodeinfo': {...},         # copied from alfred type 158
                   'statistics': {
                      'uptime': double,       # seconds
                      'memory_usage': double, # 0..1
                      'clients': double,
                      'rootfs_usage': double, # 0..1
                      'loadavg': double,
                      'gateway': mac
                    }
                 },
        ...
      }
      'timestamp': isoformat
    }

### flags (bool)

- online
- gateway

# Removing owner information

If you'd like to redact information about the node owner from `nodes.json`,
you may use a filter like [jq]. In this case, specify an output directory
different from your webserver directory, e.g.:

    ./backend.py -d /ffmap-data

Don't write to files generated in there. ffmap-backend uses them as its
database.

After running ffmap-backend, copy `graph.json` to your webserver. Then,
filter `nodes.json` using `jq` like this:

     jq '.nodes = (.nodes | with_entries(del(.value.nodeinfo.owner)))' \
       < /ffmap-data/nodes.json > /var/www/data/nodes.json

This will remove owner information from nodes.json before copying the data
to your webserver.

[jq]: https://stedolan.github.io/jq/