fix(agent): detect IPv6-bound listening ports - #27765
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Closes #15675
Dev servers that bind to the IPv6 wildcard address (Next.js, Node's default
http.Server, Go'snet.Listenon wildcard addresses, and others) never showed up in the dashboard Ports panel, even though they were listening and reachable. The agent's port scanner only callednetstat.TCPSocks, which reads/proc/net/tcp(IPv4 only); an[::]dual-stack socket lives exclusively in/proc/net/tcp6, so the panel reported "No open ports were detected."Also scan
netstat.TCP6Socksand merge the results into the existing dedupe loop. The IPv6 scan failure is non-fatal so hosts with IPv6 disabled (missing/proc/net/tcp6, Windows with the v6 stack off) keep their IPv4 results instead of the Ports panel 500ing.Both captures below:
python3 -m http.server 5123 --bind ::running in the same workspace, built from main vs this branch (full recordings).Before
After
Debugging and decision log
next-serverlistening on*:3000perss -tlnp,curlreturning 200, butGET /api/v2/workspaceagents/{agent}/listening-portsreturning{"ports": []}. Port 3000 (hex0BB8) present in/proc/net/tcp6, absent from/proc/net/tcp.agent/ports_supported.goonly callsnetstat.TCPSocks; the library'sTCP6Socks(parses/proc/net/tcp6on Linux,GetTcp6Table2on Windows) was never referenced.0.0.0.0) listener was detected correctly, isolating the bug to the missing IPv6 scan.ports_unsupported.go, which returns an empty list rather than erroring.osListeningPortsGetterbehind theListeningPortsGetterinterface from fix: mock Agent querying OS for listening ports in tests #20842, so the fake used by coderd tests is unaffected.seenmap covers dual-stack sockets that appear in both tables on Windows.TestOSListeningPortsGetter_IPv6listens on[::]:0and asserts detection; it skips when the host can't bind IPv6. Verified it fails against the pre-fix code.