Allow filtering by interface speed on machine listing

[Steve Rydz]

There is a roadmap item which requires the machine listing to allow filtering by link speed. The way this should work is the filter contains a list of all the link speeds which are being used in all interfaces. Besides each speed there is a count of the number of machines which have at least one interface using that speed.

We currently don't have interface data for the machines in the machine listing. Even with that we'd have to do a lot of data manipulation to get the data in the format required for filtering.

Ideally we'd have something in the machine object that gives up the link speeds for the interfaces.

[Steve Rydz (steverydz)]

After some more investigation I can see that the filters do work with arrays. So, in order to get the filters to work as we want them we would need ideally an array of all interface link speeds e.g. ["1 Gbps", "5 Gbps"], failing that we'd need the interfaces data for each machine in the machines table and we can construct that array by looping through the interfaces (not ideal).

[Lee Trager (ltrager)]

The related branch adds a new field to the machine output on the websocket, link_speeds. This is a sorted unique list of every detected link_speed on the machine with a speed greater than zero. This should allow you to create a filter similarly to how subnets and fabrics are done.