Both kubedns and dnsmasq modes are long not maintained.
We should run dns_late steps at the end because sshd
makes DNS lookups during Ansible run and has 2s timeouts
for each failed lookup trying to connect to coredns before
it is ready.
- Exclude kubelet CPU/RAM (kube-reserved) from cgroup. It decreases a
chance of overcommitment
- Add a possibility to modify Kubelet node-status-update-frequency
- Add a posibility to configure node-monitor-grace-period,
node-monitor-period, pod-eviction-timeout for Kubernetes controller
manager
- Add Kubernetes Relaibility Documentation with recomendations for
various scenarios.
Signed-off-by: Sergii Golovatiuk <sgolovatiuk@mirantis.com>
Also adds calico-rr group if there are standalone etcd nodes.
Now if there are 50 or more nodes, 3 etcd nodes will be standalone.
If there are 200 or more nodes, 2 kube-masters will be standalone.
If thresholds are exceeded, kube-node group cannot add nodes that
belong to etcd or kube-master groups (according to above statements).
* Add restart for weave service unit
* Reuse docker_bin_dir everythere
* Limit systemd managed docker containers by CPU/RAM. Do not configure native
systemd limits due to the lack of consensus in the kernel community
requires out-of-tree kernel patches.
Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
* Add dns_replicas, dns_memory/cpu_limit/requests vars for
dns related apps.
* When kube_log_level=4, log dnsmasq queries as well.
* Add log level control for skydns (part of kubedns app).
* Add limits/requests vars for dnsmasq (part of kubedns app) and
dnsmasq daemon set.
* Drop string defaults for kube_log_level as it is int and
is defined in the global vars as well.
* Add docs
Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
When download_run_once with download_localhost is used, docker is
expected to be running on the delegate localhost. That may be not
the case for a non localhost delegate, which is the kube-master
otherwise. Then the dnsmasq role, had it been invoked early before
deployment starts, would fail because of the missing docker dependency.
* Fix that dependency on docker and do not pre download dnsmasq image
for the dnsmasq role, if download_localhost is disabled.
* Remove become: false for docker CLI invocation because that's not
the common pattern to allow users access docker CLI w/o sudo.
* Fix opt bin path hack for localhost delegate to ignore errors when
it fails with "sudo password required" otherwise.
* Describe download_run_once with download_localhost use case in docs
as well.
Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
