Prerequisites

NMIS version 8.3.18G or greater.

Unix Shell access to the NMIS server and suitable Unix privileges to edit the NMIS configuration files, usually a member of the group "nmis" or the root user.

Introduction

While working with customers who wanted to extend NMIS and make it even more of a Network Management System, to support parts of their operational process, to integrate more closely with their ITIL service management processes for example, we found that it would become difficult for them to maintain the customisations of the extended data collection, to better support NMIS users, we have made the way "Tables" in NMIS are defined and how they are shown in the Menu.

This article will briefly describe how these capability works and how it support operational agility.

Custom Tables in NMIS

What are Tables in NMIS

To use NMIS various data is required, this data represents policies or configuration or credentials or a combination of all of those.  In the past NMIS users have added tables as they needed and this required some Perl coding, to support faster and more easily modified tables in NMIS, the table definitions are now defined outside of the code base, making the tables themselves configuration items.  So like the chicken and the egg, you need to start with something.

Tables used in NMIS

The following tables are used in NMIS, this includes the new table, Tables.nmis which now allows dynamic definition of tables.

Table Configuration

Each table has a table configuration file, these files are in essence little bits of code, which is evaluated at run time.  These files live in /usr/local/nmis8/conf and all begin with "Table-", so the table configuration for Nodes.nmis is called Table-Nodes.nmis.  The contents of the looks like:

...

SampleTable => [

{ 

  Email => { 

    header => 'Email Address', 

    display => 'key,header,text', 

    value => [""] 

  }

},

{ 

  Married => { 

    header => 'Married', 

    display => 'popup',

    value => ["true", "false"] 

  }

}, 

Adding a New Table to NMIS

The following steps are required to add a new table:

1. Create a table configuration
2. Add the table to Tables.nmis
3. Create permissions in Access.nmis
4. Link to any other data

Create a Table Configuration

Create a file in /usr/local/nmis8/conf/, in our case /usr/local/nmis8/conf/Table-SampleTable.nmis, and add the appropriate configuration.

Add the table to Tables.nmis

Using the GUI or from the Unix prompt add the new table to Tables.nmis.

...

Refresh the NMIS Dashboard and your new table will exist in the menu, but you can't access it yet.

Create permissions in Access.nmis

You need to tell NMIS what Access permissions to add this with, we have created a script to add the tables with the default permissions which is as described in the table below, the command to run to add the permissions is.

...

This step is intentionally done using the Unix shell, as we want to ensure that people adding privileges are truly NMIS admins and not someone sneaking up and using a browser window.

View the Table and Add Something

If you haven't already, refresh the NMIS Dashboard and access the new table through the menu, in this example "System -> System Configuration -> Sample Table". It will likely have an error message like "Error on loading table SampleTable" this is because there was not data.  

...

Linking Data Between Tables

So creating tables isn't that thrilling but what if we could start linking data between them, this is much more useful when wanting to add properties to the Nodes table for example, but lets add a look up to our SampleTable.

...

Yes it really is that easy.

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