chore(portal): Fix flaky test and relays load balancing selection (#4230)

A few gifts for @thomaseizinger 

Unblocks
https://github.com/firezone/firezone/pull/4213#issuecomment-2007187811
Closes #3838

elixir/apps/domain/lib/domain/auth/identity/sync.ex

@@ -38,13 +38,11 @@ defmodule Domain.Auth.Identity.Sync do
       :actor_ids_by_provider_identifier,
       fn _repo,
          %{
-           plan_identities: {_insert, _update, delete},
-           identities: identities,
+           update_identities_and_actors: update_identities,
            insert_identities: insert_identities
          } ->
         actor_ids_by_provider_identifier =
-          for identity <- identities ++ insert_identities,
-              identity.provider_identifier not in delete,
+          for identity <- update_identities ++ insert_identities,
               into: %{} do
             {identity.provider_identifier, identity.actor_id}
           end
@@ -140,10 +138,22 @@ defmodule Domain.Auth.Identity.Sync do
       |> Enum.filter(fn identity ->
         identity.provider_identifier in provider_identifiers_to_update
       end)
-      # make sure that deleted identities are in the end in case of conflicts
-      |> Enum.sort_by(& &1.deleted_at, :desc)
       |> repo.preload(:actor)
-      |> Map.new(&{&1.provider_identifier, &1})
+      |> Enum.reduce(%{}, fn identity, acc ->
+        acc_identity = Map.get(acc, identity.provider_identifier)
+
+        # make sure that deleted identities are have the least priority in case of conflicts
+        cond do
+          is_nil(acc_identity) ->
+            Map.put(acc, identity.provider_identifier, identity)
+
+          is_nil(acc_identity.deleted_at) ->
+            acc
+
+          true ->
+            Map.put(acc, identity.provider_identifier, identity)
+        end
+      end)
 
     provider_identifiers_to_update
     |> Enum.uniq()

elixir/apps/domain/lib/domain/gateways.ex

@@ -339,7 +339,7 @@ defmodule Domain.Gateways do
     # Replace the location with the approximate distance to the client
     |> Enum.map(fn
       {{gateway_lat, gateway_lon}, gateway} when is_nil(gateway_lat) or is_nil(gateway_lon) ->
-        {Geo.fetch_radius_of_earth_km!(), gateway}
+        {nil, gateway}
 
       {{gateway_lat, gateway_lon}, gateway} ->
         distance = Geo.distance({lat, lon}, {gateway_lat, gateway_lon})

elixir/apps/domain/lib/domain/geo.ex

@@ -1,10 +1,6 @@
 defmodule Domain.Geo do
   @radius_of_earth_km 6371.0
 
-  # Since most of our customers are from US we use
-  # geographic center of USA as default coordinates
-  @default_coordinates {39.8283, -98.5795}
-
   @coordinates_by_code %{
                          "AF" => {33, 65},
                          "AX" => {60.116667, 19.9},
@@ -259,10 +255,6 @@ defmodule Domain.Geo do
                        |> Enum.map(fn {code, {lat, lon}} -> {code, {lat * 1.0, lon * 1.0}} end)
                        |> Map.new()
 
-  def fetch_radius_of_earth_km! do
-    @radius_of_earth_km
-  end
-
   def distance({lat1, lon1}, {lat2, lon2}) do
     d_lat = degrees_to_radians(lat2 - lat1)
     d_lon = degrees_to_radians(lon2 - lon1)
@@ -282,7 +274,10 @@ defmodule Domain.Geo do
   end
 
   def maybe_put_default_coordinates(country_code, {nil, nil}) do
-    Map.get(@coordinates_by_code, country_code, @default_coordinates)
+    case Map.get(@coordinates_by_code, country_code) do
+      {lat, lon} -> {lat, lon}
+      nil -> {nil, nil}
+    end
   end
 
   def maybe_put_default_coordinates(_country_code, {lat, lon}) do

elixir/apps/domain/lib/domain/relays.ex

@@ -322,7 +322,7 @@ defmodule Domain.Relays do
     end)
     |> Enum.map(fn
       {{nil, nil}, relay} ->
-        {Geo.fetch_radius_of_earth_km!(), relay}
+        {nil, relay}
 
       {{relay_lat, relay_lon}, relay} ->
         distance = Geo.distance({lat, lon}, {relay_lat, relay_lon})