neiam /apollos_crib

It's Apollo's Crib

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Say which clients are on the other end, not just how many

4fa4e81 · Gabriel Morell · 2026-09-03 00:31

11 files +59 -14

Message

{commit_body(@commit)}

Files changed

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

+24 −10

@@ -68,7 +68,7 @@ defmodule RoomSanctum.Worker.Ankyra do

68	68	parent = self()
69	69	username = state.ankyra.username
70	70
71		− spawn(fn -> send(parent, {:status_result, count_mqtt_connections(username)}) end)
	71	+ spawn(fn -> send(parent, {:status_result, connected_clients(username)}) end)
72	72
73	73	{:noreply, state}
74	74	end

@@ -115,7 +115,8 @@ defmodule RoomSanctum.Worker.Ankyra do

115	115	end
116	116
117	117	@doc """
118		− How many clients are attached to this Ankyra, or nil if we could not find out.
	118	+ Who is attached to this Ankyra, as `%{count: n, client_ids: ids}` -- or nil
	119	+ if we could not find out.
119	120
120	121	RabbitMQ will not answer this over AMQP. An MQTT subscriber's queue is
121	122	exclusive to the connection that made it, so a passive `queue.declare` from

@@ -126,23 +127,36 @@ defmodule RoomSanctum.Worker.Ankyra do

126	127	receiving.
127	128
128	129	The management API does know. Every connection carries the protocol it
129		− speaks and the user it authenticated as, and an Ankyra is a rabbit user --
130		− so MQTT connections under that username are exactly its clients. Counting
131		− connections rather than probing per-client queues also drops the dependency
132		− on `client_ids`, which this worker only re-reads once a minute.
	130	+ speaks, the user it authenticated as, and -- for MQTT -- the client id it
	131	+ announced. An Ankyra is a rabbit user, so MQTT connections under that
	132	+ username are exactly its clients, and their ids are the ones the allow-list
	133	+ is written in.
133	134
134		− nil rather than 0 when the API cannot be reached: "we do not know" and
	135	+ `count` is every matching connection; `client_ids` only those that announced
	136	+ one. They are not always the same number, which is why the count is not
	137	+ taken from the length of the list: a connection with no client id still has
	138	+ someone on the end of it.
	139	+
	140	+ nil rather than zero when the API cannot be reached: "we do not know" and
135	141	"nobody is listening" are different things, and the page draws them
136	142	differently. Reporting the unreachable case as zero is the bug this replaces.
137	143	"""
138		− def count_mqtt_connections(username) do
	144	+ def connected_clients(username) do
139	145	cfg = Application.get_env(:room_sanctum, :rabbit_mgmt, [])
140	146
141	147	with url when is_binary(url) <- cfg[:url],
142	148	{:ok, %HTTPoison.Response{status_code: 200, body: body}} <- fetch_connections(url, cfg),
143	149	{:ok, connections} when is_list(connections) <- Jason.decode(body) do
144	150	vhost = cfg[:vhost] \|\| "/"
145		− Enum.count(connections, &mqtt_connection_for?(&1, username, vhost))
	151	+ mine = Enum.filter(connections, &mqtt_connection_for?(&1, username, vhost))
	152	+
	153	+ client_ids =
	154	+ mine
	155	+ \|> Enum.map(&get_in(&1, ["client_properties", "client_id"]))
	156	+ \|> Enum.filter(&is_binary/1)
	157	+ \|> Enum.sort()
	158	+
	159	+ %{count: length(mine), client_ids: client_ids}
146	160	else
147	161	other ->
148	162	Logger.debug("ankyra: could not read connections from management API: #{inspect(other)}")

@@ -156,7 +170,7 @@ defmodule RoomSanctum.Worker.Ankyra do

156	170	# ever sent and the badge stuck on "checking" forever.
157	171	defp fetch_connections(url, cfg) do
158	172	HTTPoison.get(
159		− String.trim_trailing(url, "/") <> "/api/connections?columns=protocol,user,vhost",
	173	+ String.trim_trailing(url, "/") <> "/api/connections?columns=protocol,user,vhost,client_properties.client_id",
160	174	[{"accept", "application/json"}],
161	175	hackney: [basic_auth: {to_string(cfg[:username]), to_string(cfg[:password])}],
162	176	timeout: 2_000,

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

+22 −2

@@ -12,6 +12,7 @@ defmodule RoomSanctumWeb.AnkyraLive.Show do

12	12	{:ok,
13	13	socket
14	14	\|> assign(:consumer_count, nil)
	15	+ \|> assign(:connected_client_ids, [])
15	16	\|> assign(:broker, default_broker())}
16	17	end
17	18

@@ -25,8 +26,20 @@ defmodule RoomSanctumWeb.AnkyraLive.Show do

25	26	end
26	27
27	28	@impl true
28		− def handle_info({:ankyra_status, count}, socket) do
29		− {:noreply, assign(socket, :consumer_count, count)}
	29	+ def handle_info({:ankyra_status, nil}, socket) do
	30	+ # The broker could not be asked. Say nothing rather than report an empty
	31	+ # room -- the badge draws nil as "checking".
	32	+ {:noreply,
	33	+ socket
	34	+ \|> assign(:consumer_count, nil)
	35	+ \|> assign(:connected_client_ids, [])}
	36	+ end
	37	+
	38	+ def handle_info({:ankyra_status, %{count: count, client_ids: client_ids}}, socket) do
	39	+ {:noreply,
	40	+ socket
	41	+ \|> assign(:consumer_count, count)
	42	+ \|> assign(:connected_client_ids, client_ids)}
30	43	end
31	44
32	45	@impl true

@@ -70,6 +83,13 @@ defmodule RoomSanctumWeb.AnkyraLive.Show do

70	83	{:noreply, assign_pairing(socket, broker)}
71	84	end
72	85
	86	+ # A client that auto-registers after this page was rendered is connected and
	87	+ # allowed, but the copy of the allow-list in the socket predates it. Drawing
	88	+ # it anyway beats a client that is plainly attached and nowhere on screen.
	89	+ def unregistered_connected(ankyra, connected_client_ids) do
	90	+ connected_client_ids -- (ankyra.client_ids \|\| [])
	91	+ end
	92	+
73	93	defp assign_pairing(socket, broker) do
74	94	uri = pairing_uri(socket.assigns.ankyra, broker)
75	95

modified apps/room_sanctum/lib/room_sanctum_web/live/cfg_ankyra/show.html.heex

+13 −2

@@ -28,7 +28,7 @@

28	28	<i class="fas fa-fw fa-plug-circle-xmark"></i> no subscribers
29	29	</span>
30	30	<% n -> %>
31		− <span class="badge badge-success gap-2">
	31	+ <span class="badge badge-success gap-2" title={Enum.join(@connected_client_ids, ", ")}>
32	32	<i class="fas fa-fw fa-plug"></i> <%= n %> subscriber<%= if n == 1, do: "", else: "s" %>
33	33	</span>
34	34	<% end %>

@@ -123,13 +123,18 @@

123	123	</div>
124	124
125	125	<div class="flex flex-wrap gap-2 my-2">
126		− <%= if @ankyra.client_ids == [] do %>
	126	+ <%= if @ankyra.client_ids == [] and @connected_client_ids == [] do %>
127	127	<span class="text-sm opacity-60">
128	128	<%= if @ankyra.auto_register_clients, do: "No client IDs yet — first connection will be auto-registered.", else: "No client IDs registered. Add one below or enable auto-register; otherwise all connections will be denied." %>
129	129	</span>
130	130	<% else %>
131	131	<%= for cid <- @ankyra.client_ids do %>
132	132	<div class="badge badge-secondary gap-2 p-3">
	133	+ <%= if cid in @connected_client_ids do %>
	134	+ <i class="fas fa-fw fa-circle text-success text-[0.5rem]" title="Connected now"></i>
	135	+ <% else %>
	136	+ <i class="fas fa-fw fa-circle opacity-30 text-[0.5rem]" title="Not connected"></i>
	137	+ <% end %>
133	138	<span class="font-mono"><%= cid %></span>
134	139	<button
135	140	phx-click="remove-client-id"

@@ -141,6 +146,12 @@

141	146	</button>
142	147	</div>
143	148	<% end %>
	149	+ <%= for cid <- unregistered_connected(@ankyra, @connected_client_ids) do %>
	150	+ <div class="badge badge-secondary badge-outline gap-2 p-3" title="Connected and registered since this page was loaded — reload to manage it">
	151	+ <i class="fas fa-fw fa-circle text-success text-[0.5rem]"></i>
	152	+ <span class="font-mono"><%= cid %></span>
	153	+ </div>
	154	+ <% end %>
144	155	<% end %>
145	156	</div>
146	157

Parents: 88dfaaf