Expose promExporter to service or Prometheus could not scrape

[duylddev]

What motivated this proposal?

promExporter port 777 should expose to nats service so Prometheus can scrape

What is the proposed change?

  service:
    ports:
      monitor:
        enabled: true

should add promExporter: enabled: true here

Who benefits from this change?

Who doesn't want to install prometheus-nats-exporter from https://prometheus-community.github.io/helm-charts
and can use embedded pod by set enable = true

What alternatives have you evaluated?

I must write a new service to expose prompExporter 777 and update Prometheuse scrape config

[caleblloyd]

It's already enabled via the headless service, example: nats-headless:7777 Also you want to scrape each pod, not just 1 pod via a ClusterIP Service.

[duylddev]

Thank you for the really fast reply
I run wget in Prometheus and it works

What makes me confused is port 7777 isn't listed in the headless service port table. But looks like it doesn't matter, we still can connect to all ports anyway

[caleblloyd]

Ah, maybe we should go ahead and add it to the Headless Service port list if its enabled then. If you're not doing any network policy it should still work though.

[duylddev]

I have 1 more question about promExporter.
Is it compatible with Grafana Nats template?
https://grafana.com/grafana/dashboards/2279-nats-servers/

The thing is when I install a new chart from
https://artifacthub.io/packages/helm/prometheus-community/prometheus-nats-exporter
Grafana works fine.

But if I use embedded promExporter, Grafana always shows no data

[duylddev]

more information:
Prometheus scape works fine:

[martincollado]

I have 1 more question about promExporter. Is it compatible with Grafana Nats template? https://grafana.com/grafana/dashboards/2279-nats-servers/

The thing is when I install a new chart from https://artifacthub.io/packages/helm/prometheus-community/prometheus-nats-exporter Grafana works fine.

But if I use embedded promExporter, Grafana always shows no data

Did you you realice how to use the embedded promExporter on Grafana, show no data to me as well., even using the chart for helm https://github.com/nats-io/prometheus-nats-exporter/blob/main/walkthrough/grafana-jetstream-dash-helm.json

[Hema-Shiv]

Hii,
Is is possible to scrape from all 3 replicas of statefulset pods.
job_name: 'nats-jet'
static_configs:
- targets:
- nats-stgfra-nats-helm-headless.nats-fra.svc.cluster.local:7777

  Presently with this config i see only one replia being scraped.

[ajbeach2]

I was able to get this working in GKE autopilot with managed Prometheus. with GKE autopilot you need to use pod anti-affinity to distribute the replicas across nodes.

Here is my config:

# Deploy NATS JetStream using Helm
resource "helm_release" "nats" {
  name       = "nats"
  namespace  = kubernetes_namespace.nats.metadata[0].name
  repository = "https://nats-io.github.io/k8s/helm/charts/"
  chart      = "nats"
  version    = "1.2.10"  # Using the latest version
  wait       = true

  values = [
    <<-EOT
config:
  cluster:
    enabled: true
    replicas: ${var.nats_replicas}
  jetstream:
    enabled: true
    fileStore:
      pvc:
        size: ${var.nats_pvc_size}

service:
  enabled: true
  type: ClusterIP
  ports:
    nats:
      enabled: true
      port: 4222
    cluster:
      enabled: true
      port: 6222
    monitoring:
      enabled: true
      port: 8222

promExporter:
  enabled: true
  port: 7777
  podMonitor:
    enabled: true
    merge:
      apiVersion: "monitoring.googleapis.com/v1"
      kind: "PodMonitoring"
      spec:
        endpoints:
          - port: "prom-metrics"
            interval: "30s"
            path: "/metrics"
            scheme: "HTTP"
            timeout: 10s

podTemplate:
  affinity:
    podAntiAffinity:
      preferredDuringSchedulingIgnoredDuringExecution:
        - weight: 100
          podAffinityTerm:
            topologyKey: "kubernetes.io/hostname"
            labelSelector:
              matchLabels:
                app.kubernetes.io/name: nats
EOT
  ]
}