Emissary-ingress

Prometheus Metrics

Emissary-ingress is an open-source, Kubernetes-native API gateway built on Envoy Proxy.

Prometheus Metrics

Emissary-ingress exposes Prometheus metrics by default on port 8877 at /metrics — no additional service-side configuration is required. Since Emissary is built on Envoy, many metrics use the envoy_ prefix alongside ambassador_edge_stack_ metrics for Go runtime statistics.

Note

For Kubernetes deployments, ensure that port 8877 is accessible from the node where Glouton is running, or deploy Glouton as a sidecar or DaemonSet with network access to the pod.

Glouton Configuration

Linux

sudo tee /etc/glouton/conf.d/99-emissary.conf > /dev/null << 'EOF'
metric:
  prometheus:
    targets:
      - url: "http://localhost:8877/metrics"
        name: "emissary"
        allow_metrics:
          - "envoy_http_downstream_rq_total"
          - "envoy_http_downstream_cx_active"
          - "envoy_cluster_upstream_rq_total"
          - "envoy_cluster_upstream_cx_connect_fail"
          - "ambassador_edge_stack_go_goroutines"
          - "ambassador_edge_stack_go_memstats_alloc_bytes"
          - "envoy_server_uptime"
EOF

Windows

Create or edit C:\ProgramData\glouton\conf.d\99-emissary.conf:

metric:
  prometheus:
    targets:
      - url: "http://localhost:8877/metrics"
        name: "emissary"
        allow_metrics:
          - "envoy_http_downstream_rq_total"
          - "envoy_http_downstream_cx_active"
          - "envoy_cluster_upstream_rq_total"
          - "envoy_cluster_upstream_cx_connect_fail"
          - "ambassador_edge_stack_go_goroutines"
          - "ambassador_edge_stack_go_memstats_alloc_bytes"
          - "envoy_server_uptime"

Glouton automatically detects configuration changes.

Customize collected metrics

The metrics below are our recommended defaults. You can adjust the allow_metrics list to include any metric from Emissary’s statistics documentation, or use deny_metrics to exclude specific ones. See Metrics Filtering for details.

Metric	Description
envoy_http_downstream_rq_total	Total number of downstream HTTP requests received by the gateway
envoy_http_downstream_cx_active	Number of currently active downstream client connections
envoy_cluster_upstream_rq_total	Total number of requests forwarded to upstream cluster backends
envoy_cluster_upstream_cx_connect_fail	Total number of failed connection attempts to upstream backends
ambassador_edge_stack_go_goroutines	Number of active Go goroutines in the Emissary control plane
ambassador_edge_stack_go_memstats_alloc_bytes	Bytes of memory currently allocated by the Emissary Go runtime
envoy_server_uptime	Time in seconds since the Envoy server started