[PR #818] fix: check if dns listener can bind before switching #2890

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saavagebueno · 2025-11-20T08:04:18-05:00

saavagebueno commented

2025-11-20 08:04:18 -05:00

Original Pull Request: https://github.com/netbirdio/netbird/pull/818

State: closed
Merged: No

Describe your changes

Currently, there's no check if DNS listener with custom address can bind to the specified IP:Port. In cases where the DNS listener fails to bind, the system's resolvconf is still changed even though the DNS listener is not running. This causes DNS to spectacularly fail on the client system until the user runs netbird down, replacing the netbird resolvconf with the original file.

This PR tries to fix the issue by not letting netbird change resolvconf if the DNS listener fails to bind in any case.

Checklist

Is it a bug fix
Is a typo/documentation fix
Is a feature enhancement
It is a refactor
Created tests that fail without the change (if possible)
Extended the README / documentation, if necessary

**Original Pull Request:** https://github.com/netbirdio/netbird/pull/818 **State:** closed **Merged:** No --- ## Describe your changes Currently, there's no check if DNS listener with custom address can bind to the specified `IP:Port`. In cases where the DNS listener fails to bind, the system's `resolvconf` is still changed even though the DNS listener is not running. This causes DNS to spectacularly fail on the client system until the user runs `netbird down`, replacing the netbird `resolvconf` with the original file. This PR tries to fix the issue by not letting netbird change `resolvconf` if the DNS listener fails to bind in any case. ### Checklist - [X] Is it a bug fix - [ ] Is a typo/documentation fix - [ ] Is a feature enhancement - [ ] It is a refactor - [ ] Created tests that fail without the change (if possible) - [ ] Extended the README / documentation, if necessary

saavagebueno added the pull-request label 2025-11-20 08:04:18 -05:00

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main

ui-refactor

fix/rosenpass

drop-candidateviaroutes-filter

e2e-windows-dns-combined

refactor-combined

wasm-websocket-dial

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wasm-js-func-release

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Reference: SVI/netbird#2890