Ingress additionalIngresses backend service name is hardcoded, cannot be overridden

[Hesham-14]

Description

When using hdx-oss-v2.ingress.additionalIngresses to expose the OpenTelemetry Collector, the generated Ingress backend.service.name is hardcoded to the chart’s default fullname (e.g., clickstack-hdx-oss-v2).
If the actual Service name differs (e.g., clickstack-hdx-oss-v2-otel-collector), the Ingress points to a non‑existent Service and returns:

503 Service Temporarily Unavailable

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To Reproduce

1. Deploy the chart with additionalIngresses configured for OTLP/HTTP and OTLP/gRPC.
2. The collector Service is created as:

   clickstack-hdx-oss-v2-otel-collector
   

   with ports 4317 and 4318.
3. Run:

   kubectl describe ingress <ingress-name> -n clickstack

4. Output shows:

   /   clickstack-hdx-oss-v2:4318 (<error: services "clickstack-hdx-oss-v2" not found>)
   

5. Requests to the ingress host return 503.

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Expected behavior

The Ingress backend should:

• Point to the actual collector Service name, or
• Allow overriding the backend service name in values.yaml.

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Actual behavior

The backend service name is fixed to the chart’s default fullname, ignoring the actual Service name used for the collector.

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Proposed solution

Add a serviceName (or service.name) field under each additionalIngresses.hosts.paths entry in values.yaml that, if set, overrides the default fullname in the Ingress template.

Example values.yaml:

additionalIngresses:
  - name: otel-collector-http
    hosts:
      - host: otel-http.example.com
        paths:
          - path: /
            pathType: Prefix
            serviceName: clickstack-hdx-oss-v2-otel-collector
            port: 4318

Ingress template change:

service:
  name: {{ .path.serviceName | default (include "hdx-oss-v2.fullname" $) }}
  port:
    number: {{ .path.port }}

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Environment

• Chart version: 0.7.2
• Kubernetes version: v1.33.4
• Ingress controller: NGINX

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Additional context

This limitation makes it impossible to expose the collector via additionalIngresses unless the collector’s Service name matches the chart’s default fullname exactly.
Allowing a service name override would make the feature usable in more setups.