Like the _blackbox-exporter_ role, the _vmagent_ role now deploys
`vmagent` as a container. This simplifies the process considerably,
eliminating the download/transfer step.
While refactoring this role, I also changed how the trusted CA
certificates are handled. Rather than copy files, the role now expects
a `vmagent_ca_certs` variable. This variable is a mapping of
certificate name (file name without extension) to PEM contents. This
allows certificates to be defined using normal host/group variables.
Kubernetes exports a *lot* of metrics in Prometheus format. I am not
sure what all is there, yet, but apparently several thousand time series
were added.
To allow anonymous access to the metrics, I added this RoleBinding:
```yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
name: prometheus
rules:
- apiGroups:
- ""
resources:
- nodes/metrics
verbs:
- get
- nonResourceURLs:
- /metrics
verbs:
- get
```
Dustin