openstack
/
diskimage-builder
Code Issues Proposed changes

simple-init: add configurable RA timeout with network-manager 

This is a follow-on to I475a253091cbaf63687b91c748c31a6753bb0f57 as we
are still seeing issues on some clouds with unconfigured networking.

We increase the timeout, but also make it configurable so we can
fiddle it without a dib release in the gate.

To follow-on from the experimentation done by clarkb, I can confirm by
emperical testing on a Centos 7 image (from today, today being this
change's date) that setting

 net.ipv6.conf.all.autoconf=0

by itself is "fatal" and the interfaces do not come up; i.e. nm does
not by default seem to re-enable ipv6 for the interface.  However,
explicitly adding:

 IPV6INIT=yes
 IPV6_AUTOCONF=yes

to the interface file *does* seem to make it work, even if
"all.autoconf=0" is set (then again, there's also bugs about the
effect of this [1]).  However, no extant distribution (I can currently
find) does anything like this by default.

If this continues, this may be an option.  Another might be to avoid
the use of the nm-settings-ifcfg-rh profiles and move directly to nm
ini files with glean.

[1] https://bugzilla.kernel.org/show_bug.cgi?id=11655

Change-Id: I869ebffc8cde3bbff573f6583fd9dd02a5598590
This commit is contained in:
Ian Wienand 2019-08-20 16:38:31 +10:00
parent c596fb7dbd
commit aee4fc0d35
2 changed files with 13 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
diskimage_builder/elements/simple-init/post-install.d/80-simple-init
View File

@ -48,5 +48,6 @@ if [[ ${DIB_SIMPLE_INIT_NETWORKMANAGER} != 0 ]]; then
# Debian has a many year old long bug report detailing this behavior with
# the most interesting comment being at the end:
# https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=755202#331
echo 'net.ipv6.conf.default.router_solicitation_delay=15' >> /etc/sysctl.conf
DIB_SIMPLE_INIT_NETWORKMANAGER_IPV6_DELAY=${DIB_SIMPLE_INIT_NETWORKMANAGER_IPV6_DELAY:-30}
echo "net.ipv6.conf.default.router_solicitation_delay=${DIB_SIMPLE_INIT_NETWORKMANAGER_IPV6_DELAY}" >> /etc/sysctl.conf
fi

11
releasenotes/notes/simple-init-nm-delay-f579e05467785219.yaml Normal file
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@ -0,0 +1,11 @@
---
fixes:
- |
The ``DIB_SIMPLE_INIT_NETWORKMANAGER_IPV6_DELAY`` variable is
added for the ``simple-init`` element to set the
``net.ipv6.conf.default.router_solicition_delay`` sysctl setting
(it defaults to 30s). If you are seeing an extra "blank"
interface in ``nmcli con show`` it is likely that NM has not
correctly configured itself in the presence of an interface
already configured with IPV6 by the kernel. Increasing this value
may help work-around the problem.