kubernetes nginx ingress server-snippet annotation not taking effect - kubernetes

Question

I have following ingress.yaml
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: nginx-configuration-snippet
annotations:
nginx.ingress.kubernetes.io/rewrite-target: /$2
nginx.ingress.kubernetes.io/server-snippet: |
location /base/path/v1/api/update {
deny all;
return 404;
}
spec:
rules:
- http:
paths:
- path: /base/path(/|$)(.*)
backend:
serviceName: myApi
servicePort: 8080
But when I send PUT request to /base/path/v1/api/update instead of getting 404 I am getting 500 which means that the path is reachable from ingress controller. Can anybody help me identify why ?
I changed to configuration-snippet and the error I got is :
Error: exit status 1
2020/08/06 18:35:07 [emerg] 1734#1734: location "/base/path/v1/api/update" is outside location "^/base/path(/|$)(.*)" in /tmp/nginx-cfg008325631:2445
nginx: [emerg] location "/base/path/v1/api/update" is outside location "^/base/path(/|$)(.*)" in /tmp/nginx-cfg008325631:2445
nginx: configuration file /tmp/nginx-cfg008325631 test failed

Answer 1

Adding my own answer :
The final config that worked for me was :
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: nginx-configuration-snippet
annotations:
nginx.ingress.kubernetes.io/rewrite-target: /$2
nginx.ingress.kubernetes.io/server-snippet: |
location ~* "^/base/path/v1/api/update" {
deny all;
return 403;
}
spec:
rules:
- http:
paths:
- path: /base/path(/|$)(.*)
backend:
serviceName: myApi
servicePort: 8080

Answer 2

Just for other coming along here looking for a solution, worth knowing that snippets are ignored unless the nginx controller is started with the -enable-snippet option on the command line. It should be noted that this applies to nginxinc/kubernetes-ingress project.
The docs say:
Before creating a Deployment or Daemonset resource, make sure to
update the command-line arguments of the Ingress Controller container
in the corresponding manifest file according to your requirements.
For instance if you are running the Daemonset, you will have to edit the sudo nano kubernetes-ingress/deployments/daemon-set/nginx-ingress.yaml manifest and add your argument as shown below:
args:
- -nginx-configmaps=$(POD_NAMESPACE)/nginx-config
- -default-server-tls-secret=$(POD_NAMESPACE)/default-server-secret
- -enable-snippets
#- -v=3 # Enables extensive logging. Useful for troubleshooting.
#- -report-ingress-status
#- -external-service=nginx-ingress
#- -enable-prometheus-metrics
#- -global-configuration=$(POD_NAMESPACE)/nginx-configuration
Also check other Command-line Arguments in the docs here
If you are looking for helm follow this guide in the docs