fetch config json file mixed up

[jschaeff]

When munin contains several hosts with common metrics (for instance uptime or cpu), there is only one "tag" section with one host.

"tags": {
    "cpu": {
      "domain": "testnodes",
      "host": "pmtest3",
      "plugin": "cpu"
    },
}

This makes future fetch operation write all values from different hosts with the tag host="pmtest3" instead of the right one.

in fetch.py, the tags are computed out of the config file:

    return [{
            "measurement": measurement,
            "tags": config['tags'][measurement],
            "time": fields['time'],
            "fields": {key: value for key, value in fields.iteritems() if key != 'time'}
        } for measurement, fields in data.iteritems()]

As a dirty workaround, I forced domain and tags config before the return statement:

    for measurement, fields in data.iteritems():
        config['tags'][measurement]['host'] = host
        config['tags'][measurement]['domain'] = domain