* feat(worker): add metrics HTTP server and debug profiling support
- Add -metricsPort flag to enable Prometheus metrics endpoint
- Add -metricsIp flag to configure metrics server bind address
- Implement /metrics endpoint for Prometheus-compatible metrics
- Implement /health endpoint for Kubernetes readiness/liveness probes
- Add -debug flag to enable pprof debugging server
- Add -debug.port flag to configure debug server port
- Fix stats package import naming conflict by using alias
- Update usage examples to show new flags
Fixes#7843
* feat(helm): add worker metrics and health check support
- Update worker readiness probe to use httpGet on /health endpoint
- Update worker liveness probe to use httpGet on /health endpoint
- Add metricsPort flag to worker command in deployment template
- Support both httpGet and tcpSocket probe types for backward compatibility
- Update values.yaml with health check configuration
This enables Kubernetes pod lifecycle management for worker components through
proper health checks on the new metrics HTTP endpoint.
* feat(mini): align all services to share single debug and metrics servers
- Disable S3's separate debug server in mini mode (port 6060 now shared by all)
- Add metrics server startup to embedded worker for health monitoring
- All services now share the single metrics port (9327) and single debug port (6060)
- Consistent pattern with master, filer, volume, webdav services
* fix(worker): fix variable shadowing in health check handler
- Rename http.ResponseWriter parameter from 'w' to 'rw' to avoid shadowing
the outer 'w *worker.Worker' parameter
- Prevents potential bugs if future code tries to use worker state in handler
- Improves code clarity and follows Go best practices
* fix(worker): remove unused worker parameter in metrics server
- Change 'w *worker.Worker' parameter to '_' as it's not used
- Clarifies intent that parameter is intentionally unused
- Follows Go best practices and improves code clarity
* fix(helm): fix trailing backslash syntax errors in worker command
- Fix conditional backslash placement to prevent shell syntax errors
- Only add backslash when metricsPort OR extraArgs are present
- Prevents worker pod startup failures due to malformed command arguments
- Ensures proper shell command parsing regardless of configuration state
* refactor(worker): use standard stats.StartMetricsServer for consistency
- Replace custom metrics server implementation with stats.StartMetricsServer
to match pattern used in master, volume, s3, filer_sync components
- Simplifies code and improves maintainability
- Uses glog.Fatal for errors (consistent with other SeaweedFS components)
- Remove unused net/http and prometheus/promhttp imports
- Automatically provides /metrics and /health endpoints via standard implementation