In order to enable offline/intranet installation cases:
* Move DNS/resolvconf configuration to preinstall role. Remove
skip_dnsmasq_k8s var as not needed anymore.
* Preconfigure DNS stack early, which may be the case when downloading
artifacts from intranet repositories. Do not configure
K8s DNS resolvers for hosts /etc/resolv.conf yet early (as they may be
not existing).
* Reconfigure K8s DNS resolvers for hosts only after kubedns/dnsmasq
was set up and before K8s apps to be created.
* Move docker install task to early stage as well and unbind it from the
etcd role's specific install path. Fix external flannel dependency on
docker role handlers. Also fix the docker restart handlers' steps
ordering to match the expected sequence (the socket then the service).
* Add default resolver fact, which is
the cloud provider specific and remove hardcoded GCE resolver.
* Reduce default ndots for hosts /etc/resolv.conf to 2. Multiple search
domains combined with high ndots values lead to poor performance of
DNS stack and make ansible workers to fail very often with the
"Timeout (12s) waiting for privilege escalation prompt:" error.
* Update docs.
Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
Use cloud-init config to replace /etc/resolv.conf with the
content for kubelet to properly configure hostnet pods.
Do not use systemd-resolved yet, see
https://coreos.com/os/docs/latest/configuring-dns.html
"Only nss-aware applications can take advantage of the
systemd-resolved cache. Notably, this means that statically
linked Go programs and programs running within Docker/rkt
will use /etc/resolv.conf only, and will not use the
systemd-resolve cache."
Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
* Add a var for ndots (default 5) and put it hosts' /etc/resolv.conf.
* Poke kube dns container image to v1.7
* In order to apply changes to kubelet, notify it to
be restarted on changes made to /etc/resolv.conf. Ignore errors as the kubelet
may yet to be present up to the moment of the notification being processed.
* Remove unnecessary kubelet restart for master role as the node role ensures
it is up and running. Notify master static pods waiters for apiserver,
scheduler, controller-manager instead.
Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
Move updating resolvconf to the network restart handler to
ensure changes applied to the /etc/resolv.conf.
Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
* Ensure additional nameserver/search, if defined as vars.
* Don't backup changed dhclient hooks as they are going to be
executed by dhclient as well, which is not what we want.
* For debian OS family only:
- Rename nodnsupdate hook the resolvconf hook to be sourced always
before it.
- Ensure dhclient restarted via network restart to apply the
nodnsupdate hook.
* For rhel OS family, the fix TBD, it doesn't work the same way.
Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
Rename nodnsupdate hook the resolvconf hook to be sourced always
before it.
Ensure dhclient restarted via network restart to apply the
nodnsupdate hook.
Ensure additional nameserver/search, if defined as vars.
Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
