Spurious DNS requests sent every five seconds

[andrechalella]

Bug report

• I confirm this is a bug with Supabase, not with my own application.
• I confirm I have searched the Docs, GitHub Discussions, and Discord.

Describe the bug

Every five seconds, container public.ecr.aws/supabase/realtime:v2.34.4 sends the following DNS requests:

DNS:QueryId = 0x283, QUERY (Standard query), Query  for '' of type Host Addr on class Internet
DNS:QueryId = 0x284, QUERY (Standard query), Query  for '' of type AAAA on class Internet

Yes, the query is indeed for the '' domain (two apostrophes or 0x27 0x27).

To Reproduce

Steps to reproduce the behavior, please provide code snippets or a repository:

1. d=$(mktemp -d) && cd $d && npx supabase start
2. Monitor your network with Wireshark, Microsoft Network Monitor, your LAN DNS server logs...

Expected behavior

Sane address resolution behavior.

Screenshots

System information

• OS: WSL2 in Windows 11
• Version of supabase-js: 2.26.9
• Version of Node.js: mine is v22.14.0, container's is v20.19.2

Additional context

I'm not a Supabase expert. I installed it in WSL to learn and test a few months ago, and found out this while debugging a rare DNS intermittency in my local Opnsense firewall (Unbound, as per screenshot). I tracked down the requests to the exact Supabase Realtime container. Once pausing that container, the supurious requests stopped.

I think it's not a huge or critical bug, two requests (one for A and one for AAAA) every five seconds won't crash any servers, but I was trying to debug exactly a DNS failure related to "exceeded maximum number of sends". Anyway, unintended and strange behavior worth fixing.