prometheus.md

Monitoring with Prometheus

This document describes how to monitor TopoLVM and its volume metrics by Prometheus.

TopoLVM Components

The following programs export their metrics under /metrics REST API endpoint.

• topolvm-controller
• topolvm-node
• topolvm-scheduler

In addition to the standard metrics of Go programs, topolvm-node provides available bytes of each volume group. See the topolvm-node document for details.

An example scrape config looks like:

scrape_configs:
  - job_name: "topolvm"
    kubernetes_sd_configs:
      - role: pod
        namespaces:
          names: ["topolvm-system"]
    relabel_configs:
      - source_labels: [__meta_kubernetes_pod_label_app_kubernetes_io_name]
        action: keep
        regex: node
      - source_labels: [__address__, __meta_kubernetes_pod_annotation_prometheus_io_port]
        action: replace
        regex: ([^:]+)(?::\d+)?;(\d+)
        replacement: ${1}:${2}
        target_label: __address__
      - source_labels: [__address__]
        action: replace
        regex: ([^:]+)(?::\d+)?
        replacement: ${1}
        target_label: instance

PV Filesystem Usage

For TopoLVM filesystem volumes, their usage metrics are available via kubelet. See this StackOverflow article for details.

Following is an example scrape config to collect kubelet metrics.

scrape_configs:
  - job_name: 'kubernetes-nodes'
    scheme: https
    tls_config:
      ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
    bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
    kubernetes_sd_configs:
      - role: node
    relabel_configs:
      - target_label: __address__
        replacement: kubernetes.default.svc:443
      - source_labels: [__meta_kubernetes_node_name]
        regex: (.+)
        target_label: __metrics_path__
        replacement: /api/v1/nodes/${1}/proxy/metrics
      - source_labels: [__name__]
        action: drop
        regex: kubelet_runtime_operations_duration_seconds.*