feat: Advanced configuration and customization options

[lexfrei]

Description

Add advanced configuration options for better customization and fine-tuning of cloudflared behavior.

Features to implement

1. OriginRequest Configuration

• Add cloudflare.originRequest for global origin settings
• Support per-ingress originRequest overrides
• Configure timeouts, keep-alive, HTTP/2, TLS verification, etc.
• Follow Cloudflare's originRequest configuration schema

2. Customizable Liveness Probe

• Make all probe parameters configurable:
  • failureThreshold (currently hardcoded to 1)
  • timeoutSeconds
  • periodSeconds
  • initialDelaySeconds
• Maintain current defaults for backward compatibility

3. Log Level Configuration

• Add logLevel parameter (debug, info, warn, error)
• Set via TUNNEL_LOGLEVEL environment variable
• Document available log levels

4. Additional Pod Labels

• Add podLabels parameter for custom labels
• Useful for service mesh, monitoring, policies
• Merge with existing selector labels

5. Customizable Metrics Port (#14)

• Add metricsPort parameter (default: 2000)
• Use in configmap metrics config, service, and liveness probe
• Remove hardcoded port references

Why is this needed?

• OriginRequest: Fine-tune upstream connections for performance/security
• Liveness Probe: Current aggressive settings (failureThreshold=1) can cause unnecessary restarts
• Log Level: Different verbosity needed for debug vs production
• Pod Labels: Integration with external systems and policies
• Metrics Port: Allow customization for edge cases and follow best practices

Implementation Checklist

• Add originRequest support in configmap template
• Make liveness probe fully configurable in deployment
• Add logLevel environment variable
• Add podLabels to pod template
• Make metrics port configurable (closes Make metrics port customizable in cloudflare-tunnel chart #14)
• Update values.yaml with all new parameters and examples
• Add comprehensive tests
• Update values.schema.json
• Update README.md with documentation and examples

References

• OriginRequest: enhancement(cloudflare-tunnel): Add support for originRequest config cloudflare/helm-charts#61
• Liveness: Add support for customizable livenessProbe.failureThreshold cloudflare/helm-charts#82
• LogLevel: feat: Allow to configure log level via env variable cloudflare/helm-charts#96
• Labels: Add support for additional pod labels cloudflare/helm-charts#74
• Metrics Port: Make metrics port customizable in cloudflare-tunnel chart #14