Add context buttons to the links, making navigating in netbox less clicky

The menu items can easliy be personalised

• install as a any regular plugin. See https://docs.netbox.dev/en/stable/plugins/installation/
• PyPi Packagename is 'netbox-contextmenus'.
• NetBox packagename is 'netbox_contextmenus'.
• restart the netbox service

NBCM is compatible with NetBox v3 and v4.0

NBCM version <= 1.4.3 used the 'BOTTOM_BANNER' variable to inject the javascript.

As of v1.4.4, the javascript is injected using django middleware. Make sure to remove the setting from the ConfigRevision BOTTOM_BANNER or from your configuration.py The nbcm.js file located in /opt/netbox/netbox/netbox/scripts can be removed.

This is a preparation to create a GUI to modifiy the Contect Menu items

These settings can be customized using the PLUGINS_CONFIG variable in 'configuration.py'

PLUGINS_CONFIG = {
    'netbox_contextmenus': {
        'nbcmopendelay': 150
    }
}