[chore]: Replace panic() calls with proper error handling

[aaryan359]

Requirement

Summary

Several commands in the Jaeger codebase use panic() for error handling. This issue proposes replacing those panic() calls with proper error returns and handling to improve robustness and prevent unexpected runtime crashes.

Files Affected

• cmd/tracegen/main.go
• cmd/es-rollover/app/flags.go
• cmd/es-index-cleaner/app/flags.go
• cmd/internal/flags/flags.go

Problem

Using panic() for expected error scenarios:

• Causes abrupt application crashes
• Makes CLI tools less user-friendly
• Prevents graceful error reporting and testing

Proposed Solution

1. Replace panic(err) with proper error returns.
2. Update callers to handle and propagate errors appropriately.
3. Improve error messages to be more descriptive and user-friendly.
4. Add or update tests to cover error paths where applicable.

Impact

• Improves stability and reliability of Jaeger CLI tools
• Aligns with Go best practices for error handling
• No functional or API-breaking changes

[aaryan359]

@yurishkuro @jkowall
Hi! I wanted to check in here. Are the existing panic() calls intentional, or would you be open to replacing them with proper error handling?

I’ve opened a PR that replaces these panics with proper error returns, updates callers, and adjusts tests accordingly. Please let me know if this approach looks good or if you’d prefer a different direction.

[jkowall]

Good idea but @yurishkuro might have better feedback.