enable ports based on the config value in the kubernates

[nagraj321]

What happened?

I have the following daemonset.yaml my requirement is we need to enable the debug port only if services-debug is set to true.

apiVersion: apps/v1
   kind: DaemonSet
   metadata:
     name: your-daemonset
   spec:
     selector:
       matchLabels:
         app: your-app
     template:
       metadata:
         labels:
           app: your-app
       spec:
         containers:
         - name: your-container
           image: your-image
           env:
             - name: SERVICES_DEBUG
               valueFrom:
                 configMapKeyRef:
                   name: test-config
                   key: services-debug
                   optional: true
           ports:
             - name: http-port
               containerPort: 80  # Adjust as needed
               hostPort: 80        # Adjust as needed
              - name: debug-port
               containerPort: 81  # Adjust as needed
               hostPort: 81        # Adjust as needed

i have tried the following option

{{- if eq (index .Values.configMap.test-config "services-debug") "true" }}
- name: debug-port
  containerPort: {{ .Values.image.debug-port }}
  hostPort: {{ .Values.image.debug-port }}
{{- end }}

but when we use it helm is throwing

Error: parse error at (test/templates/daemonset.yaml:59): bad character U+002D '-'

also tried

{{- if eq (index .Values.configMap "test-config" "services-debug") "true" }}
- name: debug-port
  containerPort: {{ .Values.image.debug-port }}
  hostPort: {{ .Values.image.debug-port }}
{{- end }}

but giving

templates/daemonset.yaml:59:20: executing "test/templates/daemonset.yaml" at <index .Values.configMap "test-config" "services-debug">: error calling index: index of untyped nil

What did you expect to happen?

it should procced without any errors

How can we reproduce it (as minimally and precisely as possible)?

crated a config map and key which contains the hyphen in it.

Try to use the configmap key in the if condition.

Kubernetes version

$ kubectl version
Client Version: v1.29.0+rke2r1
Kustomize Version: v5.0.4-0.20230601165947-6ce0bf390ce3
Server Version: v1.29.0+rke2r1

OS version

# On Linux:
$ cat /etc/os-release
PRETTY_NAME="Debian GNU/Linux 12 (bookworm)"
NAME="Debian GNU/Linux"
VERSION_ID="12"
VERSION="12 (bookworm)"
VERSION_CODENAME=bookworm
ID=debian
HOME_URL="https://www.debian.org/"
SUPPORT_URL="https://www.debian.org/support"
BUG_REPORT_URL="https://bugs.debian.org/"
$ uname -a
Linux pamutil46-32 6.1.73+pam01 #1 SMP PREEMPT_DYNAMIC Thu Jan 18 10:16:13 PST 2024 x86_64 GNU/Linux

Output of helm version:
version.BuildInfo{Version:"v3.4.1", GitCommit:"c4e74854886b2efe3321e185578e6db9be0a6e29", GitTreeState:"clean", GoVersion:"go1.14.11"}

[sabre1041]

The issue is that a dash is included in {{ .Values.image.debug-port }} which is not supported. If you change it to {{ index .Values "image" "debug-port" }}, Helm will no longer produce en error

[nchitimilla]

@sabre1041

we have changed the "debug-port" in the values.ymal to "debugport" and updated the daemonset.yaml respectively. But still getting the same error.

{{- if eq (index .Values.configMap.test-config "services-debug") "true" }}

• name: debug-port
  containerPort: {{ .Values.image.debugport }}
  hostPort: {{ .Values.image.debugport }}
  {{- end }}

Error: parse error at (test/templates/daemonset.yaml:59): bad character U+002D '-'

{{- if eq (index .Values.configMap "test-config" "services-debug") "true" }}

• name: debug-port
  containerPort: {{ .Values.image.debugport }}
  hostPort: {{ .Values.image.debugport }}
  {{- end }}

templates/daemonset.yaml:59:20: executing "test/templates/daemonset.yaml" at <index .Values.configMap "test-config" "services-debug">: error calling index: index of untyped nil

[sabre1041]

 {{- if eq (index .Values.configMap "test-config" "services-debug" | toString) "true" }}

Values:

configMap:
  test-config:
    services-debug: false
image:
  debug-port: 81

[nchitimilla]

Still getting the same error with {{- if eq (index .Values.configMap "test-config" "services-debug" | toString) "true" }}

test/templates/daemonset.yaml:59:20: executing "test/templates/daemonset.yaml" at <index .Values.configMap "test-config" "services-debug">: error calling index: index of untyped nil

Note: the we dont have the services-debug value in values.yaml instead we have a config map where we define services-debug value.

e.g.

apiVersion: v1
kind: ConfigMap
metadata:
  name: {{ .Chart.Name }}
data:
    services-debug: true

This is deployed a test-config

[sabre1041]

@nchitimilla Can you please share as much information as possible. Your values.yaml and template files

[nchitimilla]

Provided all the necessary filles

daemonset.yaml:
apiVersion: v1
kind: ConfigMap
metadata:
name: {{ .Chart.Name }}
annotations:
reloader.stakater.com/match: "true"
data:
services-debug: {{ .Values.servicesdebug | quote }}

values.yaml
servicesdebug: false

daemonset.yaml
apiVersion: apps/v1
kind: DaemonSet
metadata:
name: {{ .Chart.Name }}
annotations:
reloader.stakater.com/auto: "true"
spec:
hostNetwork: yes
containers:
ports:
- name: http-port
containerPort: {{ .Values.image.porthttp }}
hostPort: {{ .Values.image.porthttp }}
- name: debug-port
containerPort: {{ .Values.image.debugport }}
hostPort: {{ .Values.image.debugport }}

values.yaml
image:
porthttp: 8080
debugport: 8081

[sabre1041]

@nchitimilla This structure looks totally different than the original issue.

Are you testing against the servicesdebug property in the values.yaml file and then will enable the debug-port based upon it?

[nagraj321]

@nchitimilla This structure looks totally different than the original issue.

Are you testing against the servicesdebug property in the values.yaml file and then will enable the debug-port based upon it?

Yes. If the servicesdebug is true we would like to enable the debug port

[sabre1041]

@nagraj321 @nchitimilla why are there 2 values.yaml files? A since this is a relatively flat structure, you can just perform a simple check and it should work without issue. You can remove all of the complex index logic

[nagraj321]

First daemons.yaml and values.yaml are deployed as a one service i.e. test-config which will have the common details required by the other services.

Other daemonset.yaml and values.yaml are related to some other service.

We can’t club together as this test-config service is being used by nearly 10 other services.

Now we need to look up if we have a debug enabled in the test-config service then we need to enable the debug port.

[sabre1041]

so we can assume there is a ConfigMap where you want to look up a value already on the cluster?

[nchitimilla]

so we can assume there is a ConfigMap where you want to look up a value already on the cluster?

Yes

[sabre1041]

You would want to use the lookup filter

[nagraj321]

You would want to use the lookup filter

If you can give some example or link to documentation will be helpful.

[sabre1041]

You would want to use the lookup filter

If you can give some example or link to documentation will be helpful.

https://helm.sh/docs/chart_template_guide/functions_and_pipelines/#using-the-lookup-function