* 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
```
* Allow Kubernetes Ingress resources to be probed via Blackbox
Exporter (if present) if annotated `prometheus.io/probe: "true"`
* Fix probes of Services via Blackbox Exporter. Require Blackbox
Exporter to be deployed in the same `monitoring` namespace, be
named `blackbox-exporter`, and use port 8080
* Set `prometheus.io/param` on a Kubernetes Service to scrape
the service endpoints and pass a custom query parameter
* For example, scrape Consul with `?format=prometheus`
```yaml
kind: Service
metadata:
annotations:
prometheus.io/scrape: 'true'
prometheus.io/port: '8500'
prometheus.io/path: /v1/agent/metrics
prometheus.io/param: format=prometheus
```
* Kubernetes v1.22.0 disabled kube-controller-manager insecure
port, which was used internally for Prometheus metrics scraping
* Configure Prometheus to discover and scrape endpoints for
kube-scheduler and kube-controller-manager via the authenticated
https ports, via bearer token
* Change firewall ports to allow Prometheus (on worker nodes)
to scrape kube-scheduler and kube-controller-manager targets
that run on controller(s) with hostNetwork
* Disable the insecure port on kube-scheduler
