chore(template): Add Helm helper for telemetry env vars

[Techassi]

Part of stackabletech/issues#639

Depends on

• refactor!: Update telemetry related env vars and CLI args operator-rs#1009
• feat(stackable-telemetry)!: Allow configuration of file_log_max_files operator-rs#1010
• feat(stackable-telemetry): Support JSON console log output operator-rs#1012

This adds the telemetry.envVars Helm helper to create a list of environment variables passed on the .telemetry values.

Example

Given these values form the Helm values.yaml file

telemetry:
  consoleLog:
    enabled: false
    level: warn
    format: json
  fileLog:
    enabled: true
    level: debug
    rotationPeriod: hourly
    maxFiles: 6
  otelLogExporter:
    enabled: true
    level: trace
    endpoint: my-collector:4317
  otelTraceExporter:
    enabled: true
    level: error
    endpoint: my-collector:4317

the rendered env block in the Deployment looks like

apiVersion: apps/v1
kind: Deployment
metadata:
  name: foo-operator-airflow-operator-deployment
spec:
  template:
    spec:
      containers:
        - name: airflow-operator
          env:
            - name: CONSOLE_LOG_DISABLED
              value: "true"
            - name: CONSOLE_LOG_LEVEL
              value: warn
            - name: CONSOLE_LOG_FORMAT
              value: json
            - name: FILE_LOG_DIRECTORY
              value: /stackable/logs/airflow-operator
            - name: FILE_LOG_LEVEL
              value: debug
            - name: FILE_LOG_ROTATION_PERIOD
              value: hourly
            - name: FILE_LOG_MAX_FILES
              value: 6
            - name: OTEL_LOG_EXPORTER_ENABLED
              value: "true"
            - name: OTEL_LOG_EXPORTER_LEVEL
              value: trace
            - name: OTEL_EXPORTER_OTLP_LOGS_ENDPOINT
              value: my-collector:4317
            - name: OTEL_TRACE_EXPORTER_ENABLED
              value: "true"
            - name: OTEL_TRACE_EXPORTER_LEVEL
              value: error
            - name: OTEL_EXPORTER_OTLP_TRACES_ENDPOINT
              value: my-collector:4317

Default values will be set according to the design laid out in the tracking issue.

[NickLarsenNZ]

LGTM

[NickLarsenNZ]

Release Note

All operators now have access to these telemetry related Helm values. These are the defaults:

telemetry:
  consoleLog:
    enabled: true
    level: null
    format: null
  fileLog:
    enabled: false
    level: null
    rotationPeriod: null
    maxFiles: null
  otelLogExporter:
    enabled: false
    level: null
    endpoint: null
  otelTraceExporter:
    enabled: false
    level: null
    endpoint: null

[NickLarsenNZ]

LGTM