c9c0c01d only fix the problem for new clusters

Signed-off-by: Etienne Champetier <e.champetier@ateme.com>

The important action in kubeadm-version.yml is the templating of the configuration,
not finding / setting the version

Signed-off-by: Etienne Champetier <e.champetier@ateme.com>

There are no reasons not to backup during upgrade

Signed-off-by: Etienne Champetier <e.champetier@ateme.com>

kubeadm never rotates sa.key/sa.pub, so there is no need to delete tokens/restart pods

Signed-off-by: Etienne Champetier <e.champetier@ateme.com>

kubeadm is the default for a long time now,
and admin.conf is created by it, so let kubeadm handle it

Signed-off-by: Etienne Champetier <e.champetier@ateme.com>

Signed-off-by: Etienne Champetier <e.champetier@ateme.com>

apiserver.pem is not used since ddffdb63

Signed-off-by: Etienne Champetier <e.champetier@ateme.com>

According to [etcd's docs](https://etcd.io/docs/v3.4.0/op-guide/configuration/#--log-package-levels), argument 'log-package-levels' should not contain underscores.

Using `kubeadm init phase kubeconfig all` breaks kubelet client certificate rotation
as we are missing `kubeadm init phase kubelet-finalize all` to point to `kubelet-client-current.pem`

kubeconfig format is stable so let's just use lineinfile,
this will avoid other future breakage

This revert to the logic before 6fe22483

Signed-off-by: Etienne Champetier <e.champetier@ateme.com>

code improvement

Since a790935d all proxy users
should be properly configured

Now when you have *_PROXY vars in your environment it can leads to failure
if NO_PROXY is not correct, or to persistent configuration changes
as seen with kubeadm in 1c5391dd

Instead of playing constant whack-a-bug, inject empty *_PROXY vars everywhere
at the play level, and override at the task level when needed

Signed-off-by: Etienne Champetier <e.champetier@ateme.com>

Fix "AnsibleUndefinedVariable: the inline if-expression on line xx evaluated to false and no else section was defined."

Signed-off-by: Etienne Champetier <e.champetier@ateme.com>

* Move proxy_env to kubespray-defaults/defaults

There is no reasons to use set_facts here

Signed-off-by: Etienne Champetier <e.champetier@ateme.com>

* Ensure kubeadm doesn't use proxy

*_proxy variables might be present in the environment (/etc/environment, bash profile, ...)
When this is the case we end up with those proxy configuration in /etc/kubernetes/manifests/kube-*.yaml manifests

We cannot unset env variables, but kubeadm is nice enough to ignore empty vars
https://github.com/kubernetes/kubernetes/blob/93d288e2a47fa6d497b50d37c8b3a04e91da4228/cmd/kubeadm/app/util/env.go#L27



Signed-off-by: Etienne Champetier <e.champetier@ateme.com>

By default Ansible stat module compute checksum, list extended attributes and find mime type
To find all stat invocations that really use one of those:
git grep -F stat. | grep -vE 'stat.(islnk|exists|lnk_source|writeable)'

Signed-off-by: Etienne Champetier <e.champetier@ateme.com>

This is a small step to replace "master" with "control-plane" in
Kubespray project.