sysconfig fails to apply sysctl

[Giuseppe Petralia]

We have sysconfig related to nova-compute

$ juju config sysconfig sysctl
{ vm.swappiness: 10 }

when checking the nodes we don't see vm.swappiness applied:

root@node1:~# sysctl -a | grep vm.swap
vm.swappiness = 60

Given nova-compute has its own sysctl and they are configured on the machine:

$ juju config nova-compute-kvm sysctl
{ net.ipv4.neigh.default.gc_thresh1 : 128,
  net.ipv4.neigh.default.gc_thresh2 : 28672,
  net.ipv4.neigh.default.gc_thresh3 : 32768,
  net.ipv6.neigh.default.gc_thresh1 : 128,
  net.ipv6.neigh.default.gc_thresh2 : 28672,
  net.ipv6.neigh.default.gc_thresh3 : 32768,
  net.nf_conntrack_max : 1000000,
  net.netfilter.nf_conntrack_buckets : 204800,
  net.netfilter.nf_conntrack_max : 1000000 }

we need to understand if sysconfig sysctl are wiped by
- a config change to nova-compute that applies its sysctl
- a reboot

[Zachary Zehring (zzehring)]

So after altering the sysctl for the sysconfig application [0], the file sysctl.d file was created and "sysctl -a | grep vm.swap" has been applied. From this, it looks like there's a possibility that the sysctl.d file is not written on initial deploy.

[0] juju config sysconfig sysctl="{ vm.swappiness: 10, vm.extfrag_threshold: 200, vm.watermark_scale_factor: 50 }"

[Jose Guedez (jfguedez)]

Added the charm to a fresh machine. I can confirm that the file wasn't created on charm deployment. The following file is *missing* on the new unit, but present on previous ones (with the expected content, matching the charm settings):

/etc/sysctl.d/90-charm-sysconfig.conf