Miscellaneous ¶

Source IP address ¶

By default NGINX uses the content of the header X-Forwarded-For as the source of truth to get information about the client IP address. This works without issues in L7 if we configure the setting proxy-real-ip-cidr with the correct information of the IP/network address of trusted external load balancer.

This setting can be enabled/disabled by setting use-forwarded-headers.

If the ingress controller is running in AWS we need to use the VPC IPv4 CIDR.

Another option is to enable the PROXY protocol using use-proxy-protocol: "true".

In this mode, NGINX uses the PROXY protocol TCP header to retrieve the source IP address of the connection.

This works in most cases, but if you have a Layer 7 proxy (e.g., Cloudflare) in front of a TCP load balancer, it may not work correctly. The HTTP proxy IP address might appear as the client IP address. In this case, you should also enable the use-forwarded-headers setting in addition to enabling use-proxy-protocol, and properly configure proxy-real-ip-cidr to trust all intermediate proxies (both within the private network and any external proxies).

Example configmap for setups with multiple proxies:

use-proxy-protocol: "true"
use-forwarded-headers: "true"
proxy-real-ip-cidr: "10.0.0.0/8,131.0.72.0/22,172.64.0.0/13,104.24.0.0/14,104.16.0.0/13,162.158.0.0/15,198.41.128.0/17"

Note: Be sure to use real CIDRs that match your exact environment.

Path types ¶

Each path in an Ingress is required to have a corresponding path type. Paths that do not include an explicit pathType will fail validation. By default NGINX path type is Prefix to not break existing definitions

Proxy Protocol ¶

If you are using a L4 proxy to forward the traffic to the Ingress NGINX pods and terminate HTTP/HTTPS there, you will lose the remote endpoint's IP address. To prevent this you could use the PROXY Protocol for forwarding traffic, this will send the connection details before forwarding the actual TCP connection itself.

Amongst others ELBs in AWS and HAProxy support Proxy Protocol.

Websockets ¶

Support for websockets is provided by NGINX out of the box. No special configuration required.

The only requirement to avoid the close of connections is the increase of the values of proxy-read-timeout and proxy-send-timeout.

The default value of these settings is 60 seconds.

A more adequate value to support websockets is a value higher than one hour (3600).

Optimizing TLS Time To First Byte (TTTFB) ¶

NGINX provides the configuration option ssl_buffer_size to allow the optimization of the TLS record size.

This improves the TLS Time To First Byte (TTTFB). The default value in the Ingress controller is 4k (NGINX default is 16k).

Retries in non-idempotent methods ¶

Since 1.9.13 NGINX will not retry non-idempotent requests (POST, LOCK, PATCH) in case of an error. The previous behavior can be restored using retry-non-idempotent=true in the configuration ConfigMap.

Limitations ¶

• Ingress rules for TLS require the definition of the field host

Why endpoints and not services ¶

The Ingress-Nginx Controller does not use Services to route traffic to the pods. Instead it uses the Endpoints API in order to bypass kube-proxy to allow NGINX features like session affinity and custom load balancing algorithms. It also removes some overhead, such as conntrack entries for iptables DNAT.