cluster: storage node addesses discovery, added vmauth

[AndrewChubatiuk]

• added ability to set additional storage nodes to default ones using <vmselect|vminsert>.extraArgs.storageNode array
• added storage node srv discovery if enterprise license is enabled. fixes Multi Retention Setup #273
• added optional vmauth in front of vmselect and vminsert. fixes Consider using nginx or vmauth for balancing read load to vmselects for cluster chart #376

related issue VictoriaMetrics/VictoriaMetrics#7040

[Haleygo]

added optional vmauth in front of vmselect and vminsert. fixes #376

User can only benefit more from vmauth than k8s service when address under url_prefix is pointing to a headless service, that way vmauth can resolve all the backend addresses in advance and proxy request to the least-loaded endpoint. But headless svc is not the default service type for both vmselect and vminsert here.
And I don't think we should add more logic to change the service type when enable the vmauth without making user understand why we do that. What about adding some instructions in readme?

[Haleygo]

Better to move it with other .values.license fields for better understanding.

[AndrewChubatiuk]

license can also be defined at global.license

[AndrewChubatiuk]

added failure if no license is defined with autoDiscovery enabled

[AndrewChubatiuk]

added for vmauth.enabled param description about headless services

[Haleygo]

Need to set vmselect.name to "" for the new name template to avoid creating new service.

helm-charts/charts/victoria-metrics-cluster/values.yaml

Line 71 in d478a24

name: vmselect

btw, templates seem to complicate debugging and make value modifications more fragile(like the fix needed above, before the service name is not connected with the container name).
I don't understand why we need to consolidate all the component' services into one template yaml, and they have very different port settings in the _helpers.tpl. The previous resources look easier to me only with some duplicated fields.

helm-charts/charts/victoria-metrics-cluster/templates/_helpers.tpl

Lines 261 to 288 in d478a24

	{{- define "vminsert.ports" -}}
	- name: http
	port: {{ .service.servicePort }}
	protocol: TCP
	targetPort: {{ .service.targetPort }}
	{{- range .service.extraPorts }}
	- name: {{ .name }}
	port: {{ .port }}
	protocol: TCP
	targetPort: {{ .targetPort }}
	{{- end }}
	{{- with .extraArgs.clusternativeListenAddr }}
	- name: cluster-tcp
	protocol: TCP
	port: {{ include "vm.port.from.flag" (dict "flag" .) }}
	targetPort: cluster-tcp
	{{- end }}
	{{- with .extraArgs.graphiteListenAddr }}
	- name: graphite-tcp
	protocol: TCP
	port: {{ include "vm.port.from.flag" (dict "flag" .) }}
	targetPort: graphite-tcp
	- name: graphite-udp
	protocol: UDP
	port: {{ include "vm.port.from.flag" (dict "flag" .) }}
	targetPort: graphite-udp
	{{- end }}
	{{- with .extraArgs.influxListenAddr }}

[AndrewChubatiuk]

btw, templates seem to complicate debugging and make value modifications more fragile.

having single template helps to find issues faster as it will fail in the same places for all apps and implement the same functionality for all apps at the same time

[zekker6]

LGTM in general.
Added a few suggestions to fix a typo in configs. I would expect CI to detect this, but it seems like we don't have a test set to cover this templating path. Could you add some tests to cover this part?

[AndrewChubatiuk]

Could you add some tests to cover this part?

thanks for review. added this scenario