With T260702 and T261632 out of the way, after a brief diversion due to T261487, we can now start upgrading production nodes from 5.1.3-1wm15 to 6.0.6-1wm1.
Preliminary testing on traffic-cache-atstext-buster.traffic.eqiad.wmflabs is encouraging. With this patch cherry-picked (to be merged soon) I've upgraded varnish using the following procedure:
# Set profile::cache::varnish::frontend::packages_component: component/varnish6 run-puppet-agent apt -y install libvmod-netmapper libvmod-re2 varnish-dbg varnish-modules varnish varnishkafka systemctl stop varnish-frontend run-puppet-agent
In case of necessity we can of course downgrade back from v6 to v5:
# Unset profile::cache::varnish::frontend::packages_component rm /etc/apt/sources.list.d/repository_varnish.list apt update apt remove varnish libvmod-re2 -y systemctl stop varnish-frontend run-puppet-agent
