feat: add single tailnet support to pgcoord (#9351)

coderd/database/queries/tailnet.sql

@@ -3,21 +3,36 @@ INSERT INTO
 	tailnet_clients (
 	id,
 	coordinator_id,
-	agent_id,
 	node,
 	updated_at
 )
 VALUES
-	($1, $2, $3, $4, now() at time zone 'utc')
+	($1, $2, $3, now() at time zone 'utc')
 ON CONFLICT (id, coordinator_id)
 DO UPDATE SET
 	id = $1,
 	coordinator_id = $2,
-	agent_id = $3,
-	node = $4,
+	node = $3,
 	updated_at = now() at time zone 'utc'
 RETURNING *;
 
+-- name: UpsertTailnetClientSubscription :exec
+INSERT INTO
+	tailnet_client_subscriptions (
+	client_id,
+	coordinator_id,
+	agent_id,
+	updated_at
+)
+VALUES
+	($1, $2, $3, now() at time zone 'utc')
+ON CONFLICT (client_id, coordinator_id, agent_id)
+DO UPDATE SET
+	client_id = $1,
+	coordinator_id = $2,
+	agent_id = $3,
+	updated_at = now() at time zone 'utc';
+
 -- name: UpsertTailnetAgent :one
 INSERT INTO
 	tailnet_agents (
@@ -43,6 +58,16 @@ FROM tailnet_clients
 WHERE id = $1 and coordinator_id = $2
 RETURNING id, coordinator_id;
 
+-- name: DeleteTailnetClientSubscription :exec
+DELETE
+FROM tailnet_client_subscriptions
+WHERE client_id = $1 and agent_id = $2 and coordinator_id = $3;
+
+-- name: DeleteAllTailnetClientSubscriptions :exec
+DELETE
+FROM tailnet_client_subscriptions
+WHERE client_id = $1 and coordinator_id = $2;
+
 -- name: DeleteTailnetAgent :one
 DELETE
 FROM tailnet_agents
@@ -66,12 +91,17 @@ FROM tailnet_agents;
 -- name: GetTailnetClientsForAgent :many
 SELECT *
 FROM tailnet_clients
-WHERE agent_id = $1;
+WHERE id IN (
+	SELECT tailnet_client_subscriptions.client_id
+	FROM tailnet_client_subscriptions
+	WHERE tailnet_client_subscriptions.agent_id = $1
+);
 
 -- name: GetAllTailnetClients :many
-SELECT *
+SELECT sqlc.embed(tailnet_clients), array_agg(tailnet_client_subscriptions.agent_id)::uuid[] as agent_ids
 FROM tailnet_clients
-ORDER BY agent_id;
+LEFT JOIN tailnet_client_subscriptions
+ON tailnet_clients.id = tailnet_client_subscriptions.client_id;
 
 -- name: UpsertTailnetCoordinator :one
 INSERT INTO