Machine Server

The machine state server is a centralized management application for device testing.

Code structure

The main code is structure as:

go/machine/
    source/
    processor/
    store/

Where:

types contains the Go types used across the rest of the modules.
The source module contains source.Source, a way to get update events from machines.
The store module contains store.Store, a way to persist and retrieve each machine's state.
The processor module contains processor.Processor, a way to update a machine state from an incoming event.

The main loop of machine state server looks like:

for event := range eventCh {
	store.Update(ctx, event.Host.Name, func(previous machine.Description) machine.Description {
		return processor.Process(ctx, previous, event)
	})
}

test_machine_monitor

The application that runs on each switchboard test machine and feeds information into the machine state server.

See the Design Doc.

Current Data Flow

User triggers powercycle for a machine.

initiator	message	target	notes
machineserver	>Set(ΔDescription)	DB	Description.Powercycle=true
DB	>Snapshot(ΔDescription)	powercycle_server_ansible
powercycle_server_ansible	>Set(ΔDescription)	DB	Description.Powercycle=false

How test_machine_monitor keeps machine.Description up to date.

initiator	message	target	notes
test_machine_monitor	>PubSub(Event)	machineserver	Sends results from interrogate.
test_machine_monitor	<Snapshot(Description)	DB

Legend

initiator - The entity that starts the action.
message - Shows the direction of the data flow, the transport, and the struct being moved.
target - Who the iniator is talking to.
Δ is used before a struct if only a part of that struct is being changed.