xapi/nm: Send non-empty dns to networkd when using IPv6 autoconf #6664
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Because Autoconf is not DHCP, networkd uses the dns value to write to resolv.conf. This is done on ocaml/networkd/bin/network_server.ml line 745 This allows to have non-empty resolv.conf when using IPv6 autoconf. Signed-off-by: Pau Ruiz Safont <[email protected]>
Previously both xapi and networkd had to inspect the IP configuration to decide whether the DNS values should be persistend into /etc/resolv.conf. This actually lead to a mismatch in them. Instead use an option value for DNS that simply means that if there's a value, it must be persisted. Now xapi decides the instances where these values are written. Treat a couple of empty lists as a lack of value to avoid writing empty resolv.conf files. This can happen when updating a host from previous versions, which use empty lists when using DHCP. Tested manually by installing a version with this change and restarting the toolstack. The file is kept intact, unlike the previous version of the change that did not take into account the update behaviour. Signed-off-by: Pau Ruiz Safont <[email protected]>
last-genius
approved these changes
Sep 11, 2025
minglumlu
approved these changes
Sep 12, 2025
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Because Autoconf is not DHCP, networkd uses the dns value to write to
resolv.conf. This is done on ocaml/networkd/bin/network_server.ml line 745
This allows to have non-empty resolv.conf when using IPv6 autoconf.
xapi-idl/network: Remove code duplication for DNS persistence decisions:
Previously both xapi and networkd had to inspect the IP configuration to decide
whether the DNS values should be persistend into /etc/resolv.conf. This
actually lead to a mismatch in them. Instead use an option value for DNS that
simply means that if there's a value, it must be persisted.
Now xapi decides the instances where these values are written.
Treat a couple of empty lists as a lack of value to avoid writing empty
resolv.conf files. This can happen when updating a host from previous
versions, which use empty lists when using DHCP.
Tested manually by installing a version with this change and restarting
the toolstack. The file is kept intact, unlike the previous version of
the change that did not take into account the update behaviour.
This is PR fixed version of #6586