'Kubernetes nginx ingress controller not forwarding headers with underscores

I'm having a problem where my kubernetes nginx ingress controller is NOT forwarding the headers with underscores in them.

I created a configMap with name my-release-ingress-nginx-controller with the following entry.

    enable-underscores-in-headers: "true"

After this i checked the nginx.conf file by describing the nginx ingress controller pod, using this command kubectl exec -it my-release-ingress-nginx-controller-d7648bcc8-6lfxv cat nginx.conf. There i found this underscores_in_headers on;. Even after this toggle, the nginx is still not forwarding the headers with underscores in it.

ConfigMap:

apiVersion: v1
kind: ConfigMap
metadata:
  name: my-release-ingress-nginx-controller
  namespace: default
data:
  enable-underscores-in-headers: "true"
  ignore-invalid-headers: "false"

ConfigMap describe:

Name:         my-release-ingress-nginx-controller
Namespace:    default
Labels:       <none>
Annotations:  
Data
====
enable-underscores-in-headers:
----
true
ignore-invalid-headers:
----
false
Events:
  Type    Reason  Age   From                      Message
  ----    ------  ----  ----                      -------
  Normal  CREATE  27s   nginx-ingress-controller  ConfigMap default/my-release-ingress-nginx-controller

Deployment describe

Args:
  /nginx-ingress-controller
  --publish-service=default/my-release-ingress-nginx-controller
  --election-id=ingress-controller-leader
  --ingress-class=nginx
  --configmap=default/my-release-ingress-nginx-controller

Ingress describe:

Name:             ingress-resource-1
Namespace:        default
Address:          172.31.14.220
Default backend:  default-http-backend:80 (<error: endpoints "default-http-backend" not found>)
Rules:
  Host                                               Path  Backends
  ----                                               ----  --------
  api.dev.com  
                                                     /   faq-dev:10013 (172.17.0.3:10013)
Annotations:                                         kubernetes.io/ingress.class: nginx
                                                     nginx.ingress.kubernetes.io/rewrite-target: /
Events:
  Type    Reason  Age                     From                      Message
  ----    ------  ----                    ----                      -------
  Normal  UPDATE  3m10s (x2443 over 20h)  nginx-ingress-controller  Ingress default/ingress-resource-1
  Normal  UPDATE  2m10s (x2483 over 20h)  nginx-ingress-controller  Ingress default/ingress-resource-1

PS: I have setup a single node kubernetes cluster using minikube , inside an AWS ec2 server. Also the ingress is configured as a deployment and not a daemonset.The ingress configured is the kubernetes one from this repository - https://github.com/kubernetes/ingress-nginx

kubernetesrequest-headers


Solution 1:[1]

Try this Please

apiVersion: v1
kind: ConfigMap
data:
  enable-underscores-in-headers: "true"
  ignore-invalid-headers: "false"
metadata:
  name: nginx-configuration
  namespace: default

and include the same in nginx-ingress-controller-deployment

containers:
  - name: nginx-ingress-controller
    image: <YOUR NGINX INGRSS IMAGE_NAME>
    args:
      - /nginx-ingress-controller
      - --configmap=$(POD_NAMESPACE)/nginx-configuration
    env:
      - name: POD_NAME
        valueFrom:
          fieldRef:
            fieldPath: metadata.name
      - name: POD_NAMESPACE
        valueFrom:
          fieldRef:
            fieldPath: metadata.namespace

Solution 2:[2]

apiVersion: v1
kind: ConfigMap
data:
  enable-underscores-in-headers: "true"
metadata:
  name: nginx-configuration
  namespace: default

enabling underscore in headers

After adding this to the configuration, a rolling restart is required for the config to be picked up.

Solution 3:[3]

create new configmap with the below menifest & delete the pod of nginx controller which basically create new nginx controller with new configmap configuration.

apiVersion: v1
data:
  enable-underscores-in-headers: "true"
  ignore-invalid-headers: "false"
kind: ConfigMap
metadata:
  name: my-release-ingress-nginx-controller
  namespace: default

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution Source
Solution 1
Solution 2 rohatgisanat
Solution 3

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