How to use ConfigMap configuration with Helm NginX Ingress controller - Kubernetes - kubernetes

Question

I've found a documentation about how to configure your NginX ingress controller using ConfigMap: https://kubernetes.github.io/ingress-nginx/user-guide/nginx-configuration/configmap/
Unfortunately I've no idea and couldn't find it anywhere how to load that ConfigMap from my Ingress controller.
My ingress controller:
helm install --name ingress --namespace ingress-nginx --set rbac.create=true,controller.kind=DaemonSet,controller.service.type=ClusterIP,controller.hostNetwork=true stable/nginx-ingress
My config map:
kind: ConfigMap
apiVersion: v1
metadata:
name: ingress-configmap
data:
proxy-read-timeout: "86400s"
client-max-body-size: "2g"
use-http2: "false"
My ingress:
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: ingress
annotations:
nginx.ingress.kubernetes.io/backend-protocol: "HTTPS"
spec:
tls:
- hosts:
- my.endpoint.net
secretName: ingress-tls
rules:
- host: my.endpoint.net
http:
paths:
- path: /
backend:
serviceName: web
servicePort: 443
- path: /api
backend:
serviceName: api
servicePort: 443
How do I make my Ingress to load the configuration from the ConfigMap?

Answer 1

I've managed to display what YAML gets executed by Helm using the: --dry-run --debug options at the end of helm install command. Then I've noticed that there controller is executed with the: --configmap={namespace-where-the-nginx-ingress-is-deployed}/{name-of-the-helm-chart}-nginx-ingress-controller.
In order to load your ConfigMap you need to override it with your own (check out the namespace).
kind: ConfigMap
apiVersion: v1
metadata:
name: {name-of-the-helm-chart}-nginx-ingress-controller
namespace: {namespace-where-the-nginx-ingress-is-deployed}
data:
proxy-read-timeout: "86400"
proxy-body-size: "2g"
use-http2: "false"
The list of config properties can be found here.

Answer 2

One can pass config mag properties at the time of installation too:
helm install stable/nginx-ingress --name nginx-ingress --set controller.config.use-forwarded-headers='"true"'
NOTE: for non-string values had to use single quotes around double quotes to get it working.

Answer 3

If you used helm install to install the ingress-nginx, if no explicit value for which ConfigMap the nginx controller should look at was passed, the default value seems like it is {namespace}/{release-name}-nginx-ingress-controller. This is generated by https://github.com/helm/charts/blob/1e074fc79d0f2ee085ea75bf9bacca9115633fa9/stable/nginx-ingress/templates/controller-deployment.yaml#L67. (See similar if it's a dead link).
To verify for yourself, try to find your command that you installed the ingress-nginx chart with, and add --dry-run --debug to the command. This will show you the yaml files generated by Tiller to be applied to the cluster. The line # Source: nginx-ingress/templates/controller-deployment.yaml begins the controller deployment which has an arg of --configmap=. The value of this arg is what needs to be the name of the ConfigMap for the controller to sense, and use to update its own .conf file. This could be passed explicitly, but if it is not, it will have a default value.
If a ConfigMap is created with the RIGHT name, the controller's logs will show that it picked up the configuration change and reloaded itself.
This can be verified with kubectl logs <pod-name-of-controller> -n <namespace-arg-if-not-in-default-namespace>. My log messages contained the text Configuration changes detected, backend reload required. These log messages will not be present if the ConfigMap name was wrong.
I believe the official documentation for this is unnecessarily lacking, but maybe I'm incorrect? I will try to submit a PR with these details. Someone who knows more should help flesh them out so people don't need to stumble on this unnecessarily.
Cheers, thanks for your post.

Answer 4

If you want to give your own configuration while deploying nginx-ingress-controller, you can have a wrapper Helm chart over the original nginx-ingress Helm chart and provide your own values.yaml which can have custom configuration.
Using Helm 3 here.
Create a chart:
$ helm create custom-nginx
$ tree custom-nginx
So my chart structure looks like this:
custom-nginx/
├── Chart.yaml
├── charts
├── templates
│   ├── NOTES.txt
│   ├── _helpers.tpl
│   ├── deployment.yaml
│   ├── hpa.yaml
│   ├── ingress.yaml
│   ├── service.yaml
│   ├── serviceaccount.yaml
│   └── tests
│   └── test-connection.yaml
└── values.yaml
There are a few extra things here. Specifically, I don't need the complete templates/ directory and its contents, so I'll just remove those:
$ rm custom-nginx/templates/*
$ rmdir custom-nginx/templates
Now, the chart structure should look like this:
custom-nginx/
├── Chart.yaml
├── charts
└── values.yaml
Since, we've to include the original nginx-ingress chart as a dependency, my Chart.yaml looks like this:
$ cat custom-nginx/Chart.yaml
apiVersion: v2
name: custom-nginx
description: A Helm chart for Kubernetes
# A chart can be either an 'application' or a 'library' chart.
#
# Application charts are a collection of templates that can be packaged into versioned archives
# to be deployed.
#
# Library charts provide useful utilities or functions for the chart developer. They're included as
# a dependency of application charts to inject those utilities and functions into the rendering
# pipeline. Library charts do not define any templates and therefore cannot be deployed.
type: application
# This is the chart version. This version number should be incremented each time you make changes
# to the chart and its templates, including the app version.
# Versions are expected to follow Semantic Versioning (https://semver.org/)
version: 1.39.1
# This is the version number of the application being deployed. This version number should be
# incremented each time you make changes to the application. Versions are not expected to
# follow Semantic Versioning. They should reflect the version the application is using.
appVersion: 0.32.0
dependencies:
- name: nginx-ingress
version: 1.39.1
repository: https://kubernetes-charts.storage.googleapis.com/
Here, appVersion is the nginx-controller docker image version and version matches with the nginx-ingress chart version that I am using.
The only thing left is to provide your custom configuration. Here is an stripped down version of my custom configuration:
$ cat custom-nginx/values.yaml
# Default values for custom-nginx.
# This is a YAML-formatted file.
# Declare variables to be passed into your templates.
nginx-ingress:
controller:
ingressClass: internal-nginx
replicaCount: 1
service:
externalTrafficPolicy: Local
publishService:
enabled: true
autoscaling:
enabled: true
minReplicas: 1
maxReplicas: 3
targetCPUUtilizationPercentage: "80"
targetMemoryUtilizationPercentage: "80"
resources:
requests:
cpu: 1
memory: 2Gi
limits:
cpu: 1
memory : 2Gi
metrics:
enabled: true
config:
compute-full-forwarded-for: "true"
We can check the keys that are available to use as configuration (config section in values.yaml) in https://kubernetes.github.io/ingress-nginx/user-guide/nginx-configuration/configmap/
And the rest of the configuration can be found here: https://github.com/helm/charts/tree/master/stable/nginx-ingress#configuration
Once configurations are set, just download the dependency of your chart:
$ helm dependency update <path/to/chart>
It's a good practice to do basic checks on your chart before deploying it:
$ helm lint <path/to/chart>
$ helm install --debug --dry-run --namespace <namespace> <release-name> <path/to/chart>
Then deploy your chart (which will deploy your nginx-ingress-controller with your own custom configurations).
Also, since you've a chart now, you can upgrade and rollback your chart.

Answer 5

When installing the chart through terraform, the configuration values can be set as shown below:
resource "helm_release" "ingress_nginx" {
name = "nginx"
repository = "https://kubernetes.github.io/ingress-nginx/"
chart = "ingress-nginx"
set {
name = "version"
value = "v4.0.2"
}
set {
name = "controller.config.proxy-read-timeout"
value = "86400s"
}
set {
name = "controller.config.client-max-body-size"
value = "2g"
}
set {
name = "controller.config.use-http2"
value = "false"
}
}

Answer 6

Just to confirm #NeverEndingQueue answer above, the name of the config map is present in the nginx-controller pod spec itself, so if you inspect the yaml of the nginx-controller pod: kubectl get po release-name-nginx-ingress-controller-random-sequence -o yaml, under spec.containers, you will find something like:
- args:
- /nginx-ingress-controller
- --default-backend-service=default/release-name-nginx-ingress-default-backend
- --election-id=ingress-controller-leader
- --ingress-class=nginx
- --configmap=default/release-name-nginx-ingress-controller
For example here, a config map named release-name-nginx-ingress-controller in the namespace default needs to be created.
Once done, you can verify if the changes have taken place by checking the logs. Normally, you will see something like:
I1116 10:35:45.174127 6 event.go:278] Event(v1.ObjectReference{Kind:"ConfigMap", Namespace:"default", Name:"release-name-nginx-ingress-controller", UID:"76819abf-4df0-41e3-a3fe-25445e754f32", APIVersion:"v1", ResourceVersion:"62559702", FieldPath:""}): type: 'Normal' reason: 'CREATE' ConfigMap default/release-name-nginx-ingress-controller
I1116 10:35:45.184627 6 controller.go:141] Configuration changes detected, backend reload required.
I1116 10:35:45.396920 6 controller.go:157] Backend successfully reloaded.

Answer 7

When you apply ConfigMap configuration with needful key-value data, Ingress controller picks up this information and insert it to the nested nginx-ingress-controller Pod's original configuration file /etc/nginx/nginx.conf, therefore it's easy afterwards to verify whether ConfigMap's values have been successfully reflected or not, by checking actual nginx.conf inside the corresponded Pod.
You can also check logs from the relevant nginx-ingress-controller Pod in order to check whether ConfigMap data already reloaded to the backend nginx.conf, or if not to investigate the reason.

Answer 8

Using enable-underscores-in-headers=true worked for me not enable-underscores-in-headers='"true"'
helm install nginx-ingress ingress-nginx/ingress-nginx
--namespace ingress-basic
--set controller.config.enable-underscores-in-headers=true

Answer 9

I managed to update the "large-client-header-buffers" in the nginx via configmap. Here are the steps I have followed..
Find the configmap name in the nginx ingress controller pod describition
kubectl -n utility describe pods/test-nginx-ingress-controller-584dd58494-d8fqr |grep configmap
--configmap=test-namespace/test-nginx-ingress-controller
Note: In my case, the namespace is "test-namespace" and the configmap name is "test-nginx-ingress-controller"
Create a configmap yaml
cat << EOF > test-nginx-ingress-controller-configmap.yaml
kind: ConfigMap
apiVersion: v1
metadata:
name: test-nginx-ingress-controller
namespace: test-namespace
data:
large-client-header-buffers: "4 16k"
EOF
Note: Please replace the namespace and configmap name as per finding in the step 1
Deploy the configmap yaml
kubectl apply -f test-nginx-ingress-controller-configmap.yaml
Then you will see the change is updated to nginx controller pod after mins
i.g.
kubectl -n test-namespace exec -it test-nginx-ingress-controller-584dd58494-d8fqr -- cat /etc/nginx/nginx.conf|grep large
large_client_header_buffers 4 16k;

Answer 10

Based on the NeverEndingQueue's answer I want to provide an update for Kubernetes v1.23 / Helm 3
This is my installation command + --dry-run --debug part:
helm upgrade --install ingress-nginx ingress-nginx/ingress-nginx --namespace ingress-nginx --create-namespace --dry-run --debug
This is the part we need from the generated output of the command above:
apiVersion: apps/v1
kind: DaemonSet
metadata:
...
spec:
...
template:
...
spec:
dnsPolicy: ClusterFirst
containers:
- name: controller
...
args:
- /nginx-ingress-controller
- --publish-service=$(POD_NAMESPACE)/ingress-nginx-controller
- --...
- --configmap=${POD_NAMESPACE}/ingress-nginx-controller
- --...
....
We need this part: --configmap=${POD_NAMESPACE}/ingress-nginx-controller.
As you can see, name of ConfigMap must be ingress-nginx-controller and namespace must be the one you use during chart installation (ie {POD_NAMESPACE}, in my example about this is --namespace ingress-nginx).
# nginx-config.yaml
apiVersion: v1
kind: ConfigMap
metadata:
name: ingress-nginx-controller
namespace: ingress-nginx
data:
map-hash-bucket-size: "128"
Then run kubectl apply -f nginx-config.yaml to apply ConfigMap and nginx's pod(s) will be auto-reloaded with updated config.
To check, that nginx config has been updated, find name of nginx's pod (you can use any one, if you have few nodes): kubectl get pods -n ingress-nginx (or kubectl get pods -A)
and then check config: kubectl exec -it ingress-nginx-controller-{generatedByKubernetesId} -n ingress-nginx cat /etc/nginx/nginx.conf
UPDATE:
The correct name (ie name: ingress-nginx-controller) is shown in the official docs. Conclusion: no need to reinvent the wheel.

Answer 11

What you have is an ingress yaml and not an Ingress controller deployment yaml , Ingress Controller is the Pod that actually does the work and usually is an nginx container itself. An example of such a configuration can be found here in the documentation you shared.
UPDATE
Using that example provided , you can also use following way to load config into nginx using config map
volumeMounts:
- name: nginx-config
mountPath: /etc/nginx/nginx.conf
subPath: nginx.conf
volumes:
- name: nginx-config
configMap:
name: nginx-config
nginx-config contains your nginx configuration as part of config map

Answer 12

I read the above answers but could not make it work.
What worked for me was the following:
release_name=tcp-udp-ic
# add the helm repo from NginX and update the chart
helm repo add nginx-stable https://helm.nginx.com/stable
helm repo update
echo "- Installing -${release_name}- into cluster ..."
#delete the config map if already exists
kubectl delete cm tcp-udp-ic-cm
helm del --purge ${release_name}
helm upgrade --install ${release_name} \
--set controller.image.tag=1.6.0 \
--set controller.config.name=tcp-udp-ic-cm \
nginx-stable/nginx-ingress --version 0.4.0 #--dry-run --debug
# update the /etc/nginx/nginx.conf file with my attributes, via the config map
kubectl apply -f tcp-udp-ic-cm.yaml
and the tcp-udp-ic-cm.yaml is :
kind: ConfigMap
apiVersion: v1
metadata:
name: tcp-udp-ic-cm
namespace: default
data:
worker-connections : "10000"
Essentially I need to deploy with helm the release and set the name of the config-map that is going to use. Helm creates the config-map but empty. Then I apply the config-map file in order to update the config-map resource with my values. This sequence is the only one i could make work.

Answer 13

An easier way of doing this is just modifying the values that's deployed through helm. The values needed to be changed to enter to ConfigMap are now in controller.config.entries. Show latest values with: helm show values nginx-stable/nginx-ingress and look for the format on the version you are running.
I had tons of issues with this since all references online said controller.config, until I checked with the command above.
After you've entered the values upgrade with:
helm upgrade -f <PATH_TO_FILE>.yaml <NAME> nginx-stable/nginx-ingress

Answer 14

The nginx ingress controller may cause issues with forwarding. While we were able to get it working with nginx, via X-Forwarded-Proto etc., but it was a bit complicated and convoluted.
Moving to haproxy instead resolved this problem. As well, make sure you are interfacing with the ingress controller over https or that may cause issues with keycloak.
Keycloak v18 with --proxy edge
annotations:
kubernetes.io/ingress.class: haproxy
...