Health Module

Liveness and readiness probes with SSRF protection.

What's Included

• Liveness probe (is the service alive?)
• Readiness probe (is the service ready to accept traffic?)
• Custom health checks
• SSRF protection (private IP rejection)

Quick Copy

cp -r registry/health/src/go/* yourproject/internal/health/

Usage

Basic Setup

checker := health.NewChecker()

// Add readiness checks
checker.AddCheck("database", func(ctx context.Context) error {
    return db.PingContext(ctx)
})

checker.AddCheck("redis", func(ctx context.Context) error {
    return redis.Ping(ctx).Err()
})

// Register handlers
http.Handle("/healthz", checker.LivenessHandler())
http.Handle("/readyz", checker.ReadinessHandler())

Custom Checks

checker.AddCheck("external-api", func(ctx context.Context) error {
    resp, err := http.Get("https://api.example.com/health")
    if err != nil {
        return err
    }
    if resp.StatusCode != 200 {
        return fmt.Errorf("status: %d", resp.StatusCode)
    }
    return nil
})

Endpoints

Endpoint	Purpose	Response
/healthz	Liveness probe	200 OK if alive
/readyz	Readiness probe	200 OK if all checks pass

Configuration

checker := health.NewChecker(health.Config{
    Timeout: 5 * time.Second,
})

File Reference

File	Purpose
checker.go	Health check manager
handler.go	HTTP handlers
checks.go	Built-in checks

Security Features

• SSRF protection (private IP rejection in HTTP checks)
• CRLF injection prevention
• Timeout on all checks

Tests

cd registry/health/src/go
go test -v ./...