Go: Add otel support

[tjzhang-BQ]

old PR closed to re-target at main: #3834

Transaction support is pending the Go transaction to finish, to be done in a separate pr, will add the link here.

Issue link

This Pull Request is linked to issue (URL): #3531

Checklist

Before submitting the PR make sure the following are checked:

• This Pull Request is related to one issue.
• Commit message has a detailed description of what changed and why.
• Tests are added or updated.
• CHANGELOG.md and documentation files are updated.
• Destination branch is correct - main or release
• Create merge commit if merging release branch into main, squash otherwise.

[alexey-temnikov]

@tjzhang-BQ thank you for the PR!

[alexey-temnikov]

The SetSamplePercentage method modifies shared configuration without synchronization, which could lead to race conditions in concurrent environments. Consider adding proper synchronization:

var configMutex sync.RWMutex

func (o *OpenTelemetry) SetSamplePercentage(percentage int32) error {
    configMutex.Lock()
    defer configMutex.Unlock()
    
    if !o.IsInitialized() || otelConfig == nil || otelConfig.Traces == nil {
        return fmt.Errorf("OpenTelemetry config traces not initialized")
    }
    otelConfig.Traces.SamplePercentage = percentage
    return nil
}

func (o *OpenTelemetry) GetSamplePercentage() int32 {
    configMutex.RLock()
    defer configMutex.RUnlock()
    
    if !o.IsInitialized() || otelConfig == nil || otelConfig.Traces == nil {
        return 0
    }
    return otelConfig.Traces.SamplePercentage
}

Don't forget to add the import: import "sync"

[alexey-temnikov]

nit:

The code includes good documentation, but could benefit from more examples and clearer explanations of the OpenTelemetry integration, especially for users who might not be familiar with OpenTelemetry concepts. Consider adding more comprehensive documentation with examples:

// OpenTelemetryConfig represents the configuration for OpenTelemetry integration.
//
// Example usage:
//
//     config := glide.OpenTelemetryConfig{
//         Traces: &glide.OpenTelemetryTracesConfig{
//             Endpoint:         "http://localhost:4318/v1/traces",
//             SamplePercentage: 10, // Sample 10% of commands
//         },
//         FlushIntervalMs: &interval, // interval := int64(1000)
//     }
//     err := glide.GetInstance().Init(config)
//     if err != nil {
//         log.Fatalf("Failed to initialize OpenTelemetry: %v", err)
//     }
//

[jonathanl-bq]

CString allocates memory. Where is the function to free this?

[tjzhang-BQ]

under the impression that it gets freed here in the Go code that receives error messages from Rust, would this be enough?

[yipin-chen]

LGTM on the Go changes. I think it will be a good idea to add the config example as Alexey pointed out. I did not review FFI changes.

[MikeMwita]

can consider explicitly freeing the memory here, to avoid a memory leak eveytime Init is called .
a simple :
defer C.free(unsafe.Pointer(cConfig.traces.endpoint))
would do.

[MikeMwita]

also at this point you can add
defer C.free(unsafe.Pointer(cConfig.metrics.endpoint))