neiam /apollos_crib

It's Apollo's Crib

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Ankyra: deleting one works, and its worker stops with it

17c8ef1 · Gabe Morell · 2026-11-04 22:51

✓ android / android (push) ✓ credo / credo (push) ✓ image / image (push)

17 files +95 -3

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{commit_body(@commit)}

Files changed

modified apps/room_sanctum/lib/room_sanctum/accounts.ex

+30 −1

@@ -86,6 +86,12 @@ defmodule RoomSanctum.Accounts do

86	86	@doc """
87	87	Deletes a rabbit_user.
88	88
	89	+ The row is all there is to undo. Nothing is set up on the broker when one
	90	+ is created: RabbitMQ asks room_hermes's HTTP auth backend about every
	91	+ login and topic, and that answers from this table, so once the row is gone
	92	+ the username and password stop working. Its Ankyra worker is told, so it
	93	+ stops rather than finding out on its next re-read.
	94	+
89	95	## Examples
90	96
91	97	iex> delete_rabbit_user(rabbit_user)

@@ -96,9 +102,32 @@ defmodule RoomSanctum.Accounts do

96	102
97	103	"""
98	104	def delete_rabbit_user(%RabbitUser{} = rabbit_user) do
99		− Repo.delete(rabbit_user)
	105	+ rabbit_user \|> Repo.delete() \|> tap(&stop_worker/1)
	106	+ end
	107	+
	108	+ @doc """
	109	+ Deletes a rabbit_user as `delete_rabbit_user/1` does, raising if it cannot
	110	+ -- `Ecto.StaleEntryError` when it is already gone.
	111	+
	112	+ ## Examples
	113	+
	114	+ iex> delete_rabbit_user!(rabbit_user)
	115	+ %RabbitUser{}
	116	+
	117	+ """
	118	+ def delete_rabbit_user!(%RabbitUser{} = rabbit_user) do
	119	+ deleted = Repo.delete!(rabbit_user)
	120	+ stop_worker({:ok, deleted})
	121	+ deleted
100	122	end
101	123
	124	+ # The worker re-reads its row, and stops when there is none. A cast, so it
	125	+ # is a no-op when no worker is running.
	126	+ defp stop_worker({:ok, %RabbitUser{id: id}}),
	127	+ do: RoomSanctum.Worker.Ankyra.refresh_db_cfg(to_string(id))
	128	+
	129	+ defp stop_worker(_result), do: :ok
	130	+
102	131	@doc """
103	132	Returns an `%Ecto.Changeset{}` for tracking rabbit_user changes.
104	133

modified apps/room_sanctum/lib/room_sanctum/workers/ankyra_worker.ex

+7 −1

@@ -1,6 +1,8 @@

1	1	defmodule RoomSanctum.Worker.Ankyra do
2	2	@moduledoc false
3		− use GenServer
	3	+ # Transient: a worker whose rabbit user has been deleted stops normally and
	4	+ # stays stopped, rather than being restarted into the same missing row.
	5	+ use GenServer, restart: :transient
4	6
5	7	require Logger
6	8

@@ -180,6 +182,10 @@ defmodule RoomSanctum.Worker.Ankyra do

180	182	def handle_cast(:refresh_db_cfg, state) do
181	183	p = Accounts.get_rabbit_user!(state[:id])
182	184	{:noreply, state \|> Map.put(:ankyra, p) \|> listen_for_requests()}
	185	+ rescue
	186	+ # Deleted. Raising here had the supervisor restart it straight back into
	187	+ # the same missing row, until it gave up and took every Ankyra with it.
	188	+ Ecto.NoResultsError -> {:stop, :normal, state}
183	189	end
184	190
185	191	def handle_cast({:publish, data}, state) do

modified apps/room_sanctum/lib/room_sanctum_web/live/cfg_ankyra/index.ex

+1 −1

@@ -42,7 +42,7 @@ defmodule RoomSanctumWeb.AnkyraLive.Index do

42	42	@impl true
43	43	def handle_event("delete", %{"id" => id}, socket) do
44	44	ankyra = Accounts.get_rabbit_user!(owner(socket), id)
45		− {:ok, _} = Accounts.delete_rabbit_user!(ankyra)
	45	+ Accounts.delete_rabbit_user!(ankyra)
46	46
47	47	{:noreply, stream_delete(socket, :ankyras, ankyra)}
48	48	end

added apps/room_sanctum/test/room_sanctum/delete_rabbit_user_test.exs

+48 −0

@@ -0,0 +1,48 @@

	1	+defmodule RoomSanctum.DeleteRabbitUserTest do
	2	+ @moduledoc """
	3	+ Deleting an Ankyra -- a rabbit user -- removes its row, which is all the
	4	+ broker knows it by: RabbitMQ asks room_hermes's HTTP auth backend, which
	5	+ reads this table, and nothing is provisioned on the broker itself. Its
	6	+ worker, re-reading a row that is gone, stops and stays stopped.
	7	+ """
	8	+ use RoomSanctum.DataCase
	9	+
	10	+ import RoomSanctum.OwnershipFixtures
	11	+
	12	+ alias RoomSanctum.{Accounts, Repo}
	13	+ alias RoomSanctum.Worker.Ankyra
	14	+
	15	+ setup :users_rabbit!
	16	+
	17	+ test "delete_rabbit_user!/1 removes the row and returns it" do
	18	+ ankyra = ankyra_for(owner())
	19	+
	20	+ assert %Accounts.RabbitUser{id: id} = Accounts.delete_rabbit_user!(ankyra)
	21	+ assert id == ankyra.id
	22	+ refute Repo.reload(ankyra)
	23	+ refute Accounts.find_rabbit_user(ankyra.username, ankyra.password)
	24	+ end
	25	+
	26	+ test "delete_rabbit_user!/1 raises when there is nothing left to delete" do
	27	+ ankyra = ankyra_for(owner())
	28	+ {:ok, _} = Accounts.delete_rabbit_user(ankyra)
	29	+
	30	+ assert_raise Ecto.StaleEntryError, fn -> Accounts.delete_rabbit_user!(ankyra) end
	31	+ end
	32	+
	33	+ test "delete_rabbit_user/1 removes the row" do
	34	+ ankyra = ankyra_for(owner())
	35	+
	36	+ assert {:ok, _} = Accounts.delete_rabbit_user(ankyra)
	37	+ refute Repo.reload(ankyra)
	38	+ end
	39	+
	40	+ test "a worker whose rabbit user is gone stops normally, and is not restarted" do
	41	+ ankyra = ankyra_for(owner())
	42	+ {:ok, _} = Accounts.delete_rabbit_user(ankyra)
	43	+ state = %{id: to_string(ankyra.id), ankyra: ankyra, requests: nil}
	44	+
	45	+ assert {:stop, :normal, _state} = Ankyra.handle_cast(:refresh_db_cfg, state)
	46	+ assert %{restart: :transient} = Ankyra.child_spec(id: "1")
	47	+ end
	48	+end

modified apps/room_sanctum/test/room_sanctum_web/live/ownership_test.exs

+9 −0

@@ -495,6 +495,15 @@ defmodule RoomSanctumWeb.OwnershipTest do

495	495
496	496	assert Repo.reload(theirs)
497	497	end
	498	+
	499	+ test "deletes the user's own ankyra", ctx do
	500	+ mine = ankyra_for(ctx.me)
	501	+ {:ok, live, _html} = live(ctx.conn, Routes.ankyra_index_path(ctx.conn, :index))
	502	+
	503	+ render_click(live, "delete", %{"id" => to_string(mine.id)})
	504	+
	505	+ refute Repo.reload(mine)
	506	+ end
498	507	end
499	508
500	509	defp scribus_for(user) do

Parents: feea568