* Add toleration to run node-exporter on controller nodes
* Add HostToContainer mount propagation and security context group
settings from upstream
* Fix SELinux denied accessing /host/proc/1/mounts. The mounts file
is has an SELinux type attribute init_t, but that won't allow running
the node-exporter binary so we have to use spc_t. This should be more
targeted at just the SELinux issue than making the Pod privileged
* Remove excluded mount points and filesystem types, the defaults are
https://github.com/prometheus/node_exporter/blob/v1.3.1/collector/filesystem_linux.go#L35
```
caller=collector.go:169 level=error msg="collector failed" name=filesystem duration_seconds=0.000666766 err="open /host/proc/1/mounts: permission denied"
```
```
[ 3664.880899] audit: type=1400 audit(1659639161.568:4400): avc: denied { search } for pid=28325 comm="node_exporter" name="1" dev="proc" ino=22542 scontext=system_u:system_r:container_t:s0 tcontext=system_u:system_r:init_t:s0 tclass=dir permissive=0
```
* seccomp graduated to GA in Kubernetes v1.19. Support for
seccomp alpha annotations will be removed in v1.22
* Replace seccomp annotations with the GA seccompProfile
field in the PodTemplate securityContext
* Switch profile from `docker/default` to `runtime/default`
(no effective change, since docker is the runtime)
* Verify with docker inspect SecurityOpt. Without the profile,
you'd see `seccomp=unconfined`
Related: https://github.com/poseidon/terraform-render-bootstrap/pull/215
* Change node-exporter DaemonSet tolerations from tolerating
all possible NoSchedule taints to tolerating the master taint
and the not ready taint (we'd like metrics regardless)
* Users who add custom node taints must add their custom taints
to the addon node-exporter DaemonSet. As an addon, its expected
users copy and manipulate manifests out-of-band in their own
systems
* Deployments now belong to the apps/v1 API group
* DaemonSets now belong to the apps/v1 API group
* RBAC types now belong to the rbac.authorization.k8s.io/v1 API group
* Change service discovery to relabel jobs to align with
rule expressions in upstream examples
* Use a separate service account for prometheus instead
of granting roles to the namespace's default
* Use a separate service account for node-exporter
* Update node-exporter and kube-state-metrics exporters
