weave/site/metrics.md

title, menu_order

title	menu_order
Monitoring with Prometheus	105

Two endpoints are exposed: one for the Weave Net router, and, when deployed as a Kubernetes Addon, one for the network policy controller.

Router Metrics

The endpoint address is localhost:6782; the following metrics are exposed:

• weave_connections - Number of peer-to-peer connections.
• weave_connection_terminations_total - Number of peer-to-peer connections terminated.
• weave_ips - Number of IP addresses.
• weave_max_ips - Size of IP address space used by allocator.
• weave_dns_entries - Number of DNS entries.
• weave_flows - Number of FastDP flows.

Publish Router Metrics Endpoint

By default, when started via weave launch, weave listens on its local interface to serve metrics. To publish your metrics throughout your cluster, e.g. if your prometheus server is installed on a different host machine, you need to set WEAVE_STATUS_ADDR to your corresponding IP and port. Default port is 6782.

WEAVE_STATUS_ADDR=X.X.X.X:PORT

You can set WEAVE_STATUS_ADDR=0.0.0.0:6782 to listen on all interfaces, but be aware, this may expose your metrics to the public internet.

Kubernetes Network Policy Controller Metrics

The endpoint address is localhost:6781; the following metric is exposed:

• weavenpc_blocked_connections_total - Connection attempts blocked by policy controller.

Static Configuration for Weave Net

The following YAML fragment can be used in your Prometheus configuration to scrape the router metrics endpoint:

scrape_configs:
- job_name: 'weave'
  scrape_interval: 15s
  static_configs:
  - targets: ['localhost:6782']

Discovery Configuration for Kubernetes

If you're running Weave in conjunction with Kubernetes, it is possible to discover the endpoints for all nodes automatically. The following Kubernetes config will install and configure Prometheus 1.3 on your cluster and configure it to discover and scrape the Weave endpoints:

---
apiVersion: v1
kind: ConfigMap
metadata:
  name: prometheus
data:
  prometheus.yml: |-
    global:
      scrape_interval: 15s
    scrape_configs:
    - job_name: 'weave'
      kubernetes_sd_configs:
      - api_server:
        role: pod
      relabel_configs:
      - source_labels: [__meta_kubernetes_namespace,__meta_kubernetes_pod_label_name]
        action: keep
        regex: ^kube-system;weave-net$
      - source_labels: [__meta_kubernetes_pod_container_name,__address__]
        action: replace
        target_label: __address__
        regex: ^weave;(.+?)(?::\d+)?$
        replacement: $1:6782
      - source_labels: [__meta_kubernetes_pod_container_name,__address__]
        action: replace
        target_label: __address__
        regex: ^weave-npc;(.+?)(?::\d+)?$
        replacement: $1:6781
      - source_labels: [__meta_kubernetes_pod_container_name]
        action: replace
        target_label: job
---
apiVersion: v1
kind: Service
metadata:
  labels:
    name: prometheus
  name: prometheus
spec:
  selector:
    app: prometheus
  type: NodePort
  ports:
  - name: prometheus
    protocol: TCP
    port: 9090
    nodePort: 30900
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: prometheus
spec:
  replicas: 1
  selector:
    matchLabels:
      app: prometheus
  template:
    metadata:
      name: prometheus
      labels:
        app: prometheus
    spec:
      containers:
      - name: prometheus
        image: prom/prometheus:v1.3.0
        args:
          - '-config.file=/etc/prometheus/prometheus.yml'
        ports:
        - name: web
          containerPort: 9090
        volumeMounts:
        - name: config-volume
          mountPath: /etc/prometheus
      volumes:
      - name: config-volume
        configMap:
          name: prometheus

Weave Cloud Integration

Finally, you can configure your local Prometheus instance to push metrics to Weave Cloud by including the following fragment in the prometheus.yml above (after replacing <WEAVE_CLOUD_TOKEN> with your own token):

remote_write:
  url: http://frontend.dev.weave.works/api/prom/push
  basic_auth:
    password: <WEAVE_CLOUD_TOKEN>

For information on getting started with Weave Cloud metrics, including on how to obtain your Weave Cloud token, please go here.