Backfill interface DNS fields from host resolv.conf#4994
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When the ACS payload omits DomainNameServers, netlib copies the host's resolv.conf but left the interface struct fields empty. Parse the copied content back into the interface fields. The parser follows resolv.conf(5) using the same rules as Go's net.dnsReadConfig (comment handling, whitespace splitting, last-search-wins).
xxx0624
approved these changes
Jun 8, 2026
ShelbyZ
approved these changes
Jun 10, 2026
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Summary
When the ACS payload omits DomainNameServers, netlib copies the host's resolv.conf into the task volume but leaves the interface struct fields empty. This PR populates them from the copied content so the model reflects the DNS config that containers actually use.
Implementation details
In
createResolvConf(common_linux.go), after copying the host's resolv.conf to the netns directory, parse the content and backfilliface.DomainNameServersandiface.DomainNameSearchList.The parser (
parseResolvConf) follows resolv.conf(5) using the same rules as Go'snet.dnsReadConfig:;or#are commentsnameservercontributes one IP per linesearchdirective winsTesting
Unit tests for
parseResolvConfcovering:New tests cover the changes: yes
Description for the changelog
Enhancement - Populate interface DNS fields when resolv.conf is copied from host
Additional Information
Does this PR include breaking model changes? If so, Have you added transformation functions?
No. Existing fields are populated where they were previously nil.
Does this PR include the addition of new environment variables in the README?
No.
Licensing
By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.