Add prometheus pushgateway and corresponding prometheus target config
What does this MR do and why?
- Add a new sylva unit which installs Prometheus Pushgateway exporter from prometheus HELM repo
- enable persistent volume and add peristent flags at pushgateway startup
- add a sidecar container which runs a loop script to purge metrics
- Add the corresponding Prometheus Target configuration in prometheus-resources kustomized unit
Related reference(s)
closes #1196 (closed)
Test coverage
- manual test to verify in Rancher/Prometheus GUI that pushgateway target is well seen UP
- sidecar container purge-metrics is well deployed in pushgateway pod
- pushgateway starts with required extraArgs and PV (default size 2G)
Edited by Alexandre Seitz