NagVis Geomap

Introduction

The NagVis Geomap map source was introduced in NagVis 1.7. It has been developed to get well rendered and scaled overview maps without much work.

The geomap renders several hosts on an Open Street Map powered map which is used as background image.

For the current geomap all you need is a CSV file which tells NagVis the hosts to render and the geo coordinates where the hosts should be positioned at.

Unlike the NagVis Worldmaps, which have been introduced with NagVis 1.9, the geomaps are designed to be static maps without user interaction. You can not zoom in/out and pan like you can on the worldmaps.

Prerequisites

There is no special software needed on the NagVis host. But there is one special requirement. To be able to use this feature, NagVis needs to be able to access the host geomap.nagvis.org via port 80. NagVis uses a simple HTTP based API to get the map image and the coordinates of that image.

In most cases the NagVis host does not have direct internet access. You can configure the http_proxy option in the [global] section of your NagVis main configuration to tell NagVis to use a proxy such requests. Most proxies require an authentication to control access to the internet. Please use the option http_proxy_auth to set the credentials.

The first call

NagVis comes with a demo geomap called "demo-geomap". If your NagVis is configured correctly you should see a map of germany with two nodes. One node is showing the host "ham-srv1" in Hamburg. The other host "muc-srv1" is located in Munich.

The geomap is defined using the regular map configuration file "demo-geomap.cfg". The contents look like this:

global {
    sources=geomap
    alias=Demo: 4 Geomap
    parent_map=demo-overview
    iconset=std_medium
    backend_id=demo
    # Geomap Parameters
    source_type=csv
    source_file=demo-locations
    width=800
    height=600
}

The sources=geomap line tells the map to use the geomap source for altering the map configuration. The source_type=csv (new in 1.7.4) line tells the geomap source to use the CSV file defined in the source_file=demo-locations definition located in the etc/geomap directory for gathering a list of hosts and coordinates to add to the geomap.

The demo-locations.csv file contains the following two lines:

ham-srv1;Hamburg Server 1;53.556866;9.994622
muc-srv1;Munich Server1;48.1448353;11.5580067

Each line defines one host to be added to the map. The columns are separated by ; signs. The first column contains the host-name, the second an optional alias, the third the LAT coordinate and the fourth the LONG coordinate.

(starting with git-version as of 2013-03-21): Lines starting with the usual comment characters (;, #, or //) are treated as comments.

: It is also possible to set source_type=backend to use the backend set via backend_id to gather the list of hosts to be shown on the geomap and their coordinates. This is only possible when using the livestatus backend. It fetches all hosts from the backend and uses all hosts which have the custom object variables _LAT and _LONG configured. It is possible to filter the fetched hosts by the membership in a host group by setting the option filter_group to the name of the host group.

Configuring geomaps

The geomap source uses view parameters for configuration. For details take a look at the modify view dialog which can be opened using the header menu "Actions -> Modify view".

The view parameters can also be given as map configuration attributes in the global section of the maps.