how to convert nginx-ingress annotations to --set format to enable prometheus metrics - annotations

Question

I want to set annotations on command line while installing nginx-ingress. my values.yaml file looks like below and i want to use command line argument instead of values.yaml file.
controller:
metrics:
port: 10254
enabled: true
service:
annotations:
prometheus.io/scrape: "true"
prometheus.io/port: "10254"
serviceMonitor:
enabled: true
namespace: monitoring
namespaceSelector:
any: true
I tried following arguments but its giving error
--set controller.metrics.service.annotations."prometheus\.io\/scrape"="true" --set controller.metrics.service.annotations."prometheus\.io\/port"="10254"
Error:
Error: release nginx-ingress failed: Service in version "v1" cannot be handled as a Service: v1.Service.ObjectMeta: v1.ObjectMeta.Annotations: ReadString: expects " or n, but found 1, error found in #10 byte of ...|io/port":10254,"prom|..., bigger context ...|,"metadata":{"annotations":{"prometheus.io/port":10254,"prometheus.io/scrape":true},"labels":{"app.k|...
Any suggestions how exactly these annotations should be passed ?

Answer 1

I just had the same issue! When you look at the chart, they define it as a string. So when I utilize the command below it successfully sets the values. The trick is to utilize --set-string rather than --set
helm upgrade ingress-controller ingress-nginx/ingress-nginx --namespace ingress-nginx --set controller.metrics.enabled=true --set-string controller.metrics.service.annotations."prometheus\.io/scrape"="true" --set-string controller.metrics.service.annotations."prometheus\.io/port"="10254"
Showing that the values are set when we validate this with helm get values ingress-controller --namespace ingress-nginx
controller:
metrics:
enabled: true
service:
annotations:
prometheus.io/port: "10254"
prometheus.io/scrape: "true"
Now if you would like to get the details into prometheus, then it appears that this did not work for me though. I had to utilize the controller.podAnnotations to get this working:
helm upgrade ingress-controller ingress-nginx/ingress-nginx \
--namespace ingress-nginx \
--set controller.metrics.enabled=true \
--set-string controller.podAnnotations."prometheus\.io/scrape"="true" \
--set-string controller.podAnnotations."prometheus\.io/port"="10254"
Let me know if this worked for you! :)