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Disable DNSStubListener for Flatcar Linux #9160

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merged 2 commits into from
Aug 18, 2022
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Disable DNSStubListener for Flatcar Linux #9160

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5d4a389
Disable DNSStubListener for Flatcar Linux
HoKim98 Aug 9, 2022
7861efc
Fix missing "Flatcar" condition of os_family
HoKim98 Aug 9, 2022
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4 changes: 4 additions & 0 deletions roles/kubernetes/preinstall/templates/resolved.conf.j2
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Expand Up @@ -10,4 +10,8 @@ Domains={{ ([ 'default.svc.' + dns_domain, 'svc.' + dns_domain ] + searchdomains
#MulticastDNS=no
DNSSEC=no
Cache=no-negative
{% if ansible_os_family in ["Flatcar", "Flatcar Container Linux by Kinvolk"] %}
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This looks ok to me but it may be a more general solution to deal with distributions running systemd-resolved; why limit it to just Flatcar?

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At least in my environment (Flatcar Linux) this inevitably became a problem.

I've been tracking this issue steadily until very recently, and found that it crashes when the `nodelocaldns' feature is enabled.

I don't think this works the same on other distributions (such as Ubuntu). The enable_nodelocaldns feature is already enabled by default, so I know that no other major distributions have reported problems with it.

Another peculiarity is that, at least in Flatcar Linux, the /etc/resolv.conf configuration file is not valid, and instead depends only on the systemd-resolved. However, there are several resolvconf stuffs that are specific to Flatcar Linux, but I still don't know why they exist.

Especially,

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Hmm, ok, lets go ahead with this change then and see if other deployments report this problem, I have a suspicion that ubuntu 22.04 may be affected as well bug since I'm not running that in production anywhere this is just a suspicion.

DNSStubListener=no
{% else %}
#DNSStubListener=yes
{% endif %}