Ingress NGINX Controller

This document describes how to configure your Google Kubernetes Engine deployment so that you can use Google Cloud Managed Service for Prometheus to collect metrics from the Ingress NGINX Controller. This document shows you how to do the following:

Set up the Ingress NGINX Controller to report metrics.
Configure a PodMonitoring resource for Managed Service for Prometheus to collect the exported metrics.
Access a dashboard in Cloud Monitoring to view the metrics.
Configure alerting rules to monitor the metrics.

These instructions apply only if you are using managed collection with Managed Service for Prometheus. If you are using self-deployed collection, then see the Ingress NGINX documentation for installation information.

These instructions are provided as an example and are expected to work in most Kubernetes environments. If you are having trouble installing an application or exporter due to restrictive security or organizational policies, we recommend you consult open-source documentation for support.

For information about Ingress NGINX, see Ingress NGINX.

Prerequisites

To collect metrics from the Ingress NGINX Controller by using Managed Service for Prometheus and managed collection, your deployment must meet the following requirements:

Your cluster must be running Google Kubernetes Engine version 1.21.4-gke.300 or later.
You must be running Managed Service for Prometheus with managed collection enabled. For more information, see Get started with managed collection.

Ingress NGINX exposes Prometheus-format metrics automatically; you don't have to install it separately. To verify that the Ingress NGINX Controller is exposing metrics, run the following command:

  kubectl exec -n NAMESPACE_NAME deploy/ingress-nginx-controller -- curl http://localhost:10254/metrics

Define a PodMonitoring resource

For target discovery, the Managed Service for Prometheus Operator requires a PodMonitoring resource that corresponds to the Ingress NGINX exporter in the same namespace.

You can use the following PodMonitoring configuration:

# Copyright 2022 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

apiVersion: monitoring.googleapis.com/v1
kind: PodMonitoring
metadata:
  name: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: google-cloud-managed-prometheus
spec:
  endpoints:
  - port: 10254
    scheme: http
    interval: 30s
    path: /metrics
  selector:
    matchLabels:
      app.kubernetes.io/name: ingress-nginx

Ensure that the values of the port and matchLabels fields match those of the Ingress NGINX pods that you want to monitor. By default, the Ingress NGINX Controller exposes metrics on port 10254 and has the label app.kubernetes.io/name: ingress-nginx.

To apply configuration changes from a local file, run the following command:

kubectl apply -n NAMESPACE_NAME -f FILE_NAME

You can also use Terraform to manage your configurations.

Define rules and alerts

You can use the following Rules configuration to define alerts on your Ingress NGINX metrics:

# Copyright 2022 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

apiVersion: monitoring.googleapis.com/v1
kind: Rules
metadata:
  name: ingress-nginx-rules
  labels:
    app.kubernetes.io/component: rules
    app.kubernetes.io/name: ingress-nginx-rules
    app.kubernetes.io/part-of: google-cloud-managed-prometheus
spec:
  groups:
  - name: ingress-nginx
    interval: 30s
    rules:
    - alert: NGINXIngressDroppedConnections
      annotations:
        description: |-
          NGINX Ingress dropped connections
            VALUE = {{ $value }}
            LABELS: {{ $labels }}
        summary: NGINX Ingress dropped connections (instance {{ $labels.instance }})
      expr: (nginx_ingress_controller_nginx_process_connections_total{state="accepted"} - nginx_ingress_controller_nginx_process_connections_total{state="handled"}) > 0
      for: 5m
      labels:
        severity: critical
    - alert: NGINXIngressHighRequestRate
      annotations:
        description: |-
          NGINX Ingress high request rate
            VALUE = {{ $value }}
            LABELS: {{ $labels }}
        summary: NGINX Ingress high request rate (instance {{ $labels.instance }})
      expr: rate(nginx_ingress_controller_requests[5m]) > 100
      for: 5m
      labels:
        severity: warning
    - alert: NGINXIngressLowRequestRate
      annotations:
        description: |-
          NGINX Ingress low request rate
            VALUE = {{ $value }}
            LABELS: {{ $labels }}
        summary: NGINX Ingress low request rate (instance {{ $labels.instance }})
      expr: rate(nginx_ingress_controller_requests[5m]) < 10
      for: 5m
      labels:
        severity: warning

To apply configuration changes from a local file, run the following command:

kubectl apply -n NAMESPACE_NAME -f FILE_NAME

You can also use Terraform to manage your configurations.

For more information about applying rules to your cluster, see Managed rule evaluation and alerting.

You can adjust the alert thresholds to suit your application.

Verify the configuration

You can use Metrics Explorer to verify that you correctly configured the Ingress NGINX exporter. It might take one or two minutes for Cloud Monitoring to ingest your metrics.

To verify the metrics are ingested, do the following:

In the navigation panel of the Google Cloud console, select Monitoring, and then select Metrics explorer:
Go to Metrics explorer
In the toolbar of the query-builder pane, select the button whose name is either MQL or PromQL.
Verify that PromQL is selected in the Language toggle. The language toggle is in the same toolbar that lets you format your query.

Enter and run the following query:

up{job="ingress-nginx", cluster="CLUSTER_NAME", namespace="NAMESPACE_NAME"}

View dashboards

The Cloud Monitoring integration includes the Ingress NGINX Prometheus Overview dashboard. Dashboards are automatically installed when you configure the integration. You can also view static previews of dashboards without installing the integration.

Note: Some charts in the dashboard may appear unpopulated upon initial setup because Ingress NGINX only exports metrics like nginx_ingress_controller_requests after your Ingress resource starts receiving requests.

To view an installed dashboard, do the following:

In the navigation panel of the Google Cloud console, select Monitoring, and then select Dashboards:
Go to Dashboards
Select the Dashboard List tab.
Choose the Integrations category.
Click the name of the dashboard, for example, Ingress NGINX Prometheus Overview.

To view a static preview of the dashboard, do the following:

In the navigation panel of the Google Cloud console, select Monitoring, and then select Integrations:
Go to Integrations
Click the Kubernetes Engine deployment-platform filter.
Locate the Ingress NGINX Controller integration and click View Details.
Select the Dashboards tab.

Troubleshooting

For information about troubleshooting metric ingestion problems, see Problems with collection from exporters in Troubleshooting ingestion-side problems.