Clear suma discoveries

[nelsonkopliku]

Description

This PR introduces the ability to clear up previously discovered software updates information when software updates settings get cleared themselves.

Mechanism is pretty simple:

1. attempt to clear software updates settings
2. for each registered* host issue a ClearSoftwareUpdatesDiscovery** -> host ignores previously discovered info
3. the state of the integration service is cleared up as well

* wondering whether it is enough and if we should do anything on host deregistration to wipe out software updates discovery. Deferring.

** current implementation works in a best effort fashion, meaning that failures when dispatching ClearSoftwareUpdatesDiscovery do not block the overall clear up process.

How was this tested?

Automated tests.

Note that a couple of test cases have been added:

• Trento.CommandedCase
• Trento.SoftwareUpdates.DiscoveryCase

These provide respectively a default stub for commanded dispatching and for the software updates discovery.
They come handy when a default behaviour is enough in tests and no specific expectation is needed for respective behaviours.

[dottorblaster]

Just a couple minor nitpicks but as Chester Bennington taught us in the time of our lives, in the end it doesn't even matter

[dottorblaster]

Couldn't you move this outside the if clause? You could just use Enum.map to build the commands and check the length of that list as well, but really up to you, it's a nitpick

[nelsonkopliku]

pick one

def clear_software_updates_discoveries do
  hosts = Hosts.get_all_hosts()

  Enum.each(hosts, fn %HostReadModel{id: host_id} ->
    %{host_id: host_id}
    |> ClearSoftwareUpdatesDiscovery.new!()
    |> commanded().dispatch()
  end)

  if length(hosts) > 0 do # or  if !Enum.empty?(hosts) do
    clear()
  end

  :ok
end

def clear_software_updates_discoveries do
  hosts = Hosts.get_all_hosts()

  hosts
  |> Enum.map(fn %HostReadModel{id: host_id} -> %{host_id: host_id} end)
  |> Enum.each(fn command_payload ->
    command_payload
    |> ClearSoftwareUpdatesDiscovery.new!()
    |> commanded().dispatch()
  end)

  if length(hosts) > 0 do # or  if !Enum.empty?(hosts) do
    clear()
  end

  :ok
end

[dottorblaster]

The second one monsieur 👨‍🍳 (chef kiss emoji sadly unavailable)

[nelsonkopliku]

I am fine eitherway.
I like the second option more, however it is less efficient as we iterate over items twice, but hey 😄

EDIT: Big O forgive me

[dottorblaster]