Nginx Ingress Controller Configuration Snippet

Nginx Ingress Controller is a popular open-source solution for managing ingress traffic in Kubernetes clusters. It provides a powerful and flexible way to configure the behavior of the Nginx server that handles incoming requests. One of the key features of the Nginx Ingress Controller is the ability to use configuration snippets to customize the Nginx server's behavior without modifying the main configuration file.

What is a Configuration Snippet?

A configuration snippet is a block of Nginx configuration directives that can be injected into the Nginx server's configuration at runtime. It allows you to add, modify, or remove specific configuration directives without touching the main Nginx configuration file. This is particularly useful when you want to apply custom configurations for specific ingress resources or virtual hosts.

How to Use Configuration Snippet?

To use a configuration snippet with the Nginx Ingress Controller, you need to annotate the ingress resource or virtual host with the nginx.ingress.kubernetes.io/configuration-snippet annotation. The value of this annotation should be a YAML block containing the desired Nginx configuration directives.

Here's an example of how to use the nginx.ingress.kubernetes.io/configuration-snippet annotation to add a custom header to all requests handled by the Nginx server:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: my-ingress
  annotations:
    nginx.ingress.kubernetes.io/configuration-snippet: |
      more_set_headers "Custom-Header: Custom-Value";
spec:
  rules:
    - host: example.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: my-service
                port:
                  number: 80

In this example, the nginx.ingress.kubernetes.io/configuration-snippet annotation adds the more_set_headers directive to the Nginx server's configuration. This directive sets a custom header named Custom-Header with the value Custom-Value for all requests.

Multiple Configuration Snippets

You can use multiple nginx.ingress.kubernetes.io/configuration-snippet annotations to apply multiple configuration snippets to an ingress resource or virtual host. The order of the annotations defines the order in which the configuration snippets are applied. It's important to note that if multiple snippets modify the same configuration directive, the last one takes precedence.

Conclusion

The nginx.ingress.kubernetes.io/configuration-snippet annotation is a powerful tool for customizing the behavior of the Nginx Ingress Controller. It allows you to add, modify, or remove specific Nginx configuration directives without modifying the main configuration file. This flexibility enables you to tailor the Nginx server's behavior to meet your specific requirements for different ingress resources or virtual hosts.

Make sure to check the official documentation of the Nginx Ingress Controller for more details and examples on using configuration snippets.