pkg

Go Utility Packages (v2)

Production-ready Go utility packages with OpenTelemetry instrumentation, comprehensive testing, and battle-tested components for building modern cloud-native applications.

🎯 Version 2 Status

Current Release: v2.0.0 (GA) Status: Production Ready Test Coverage: 85%

v2 Highlights: OpenTelemetry instrumentation across all packages, 85% test coverage, modernized dependencies

Breaking Change: v1 does not include OpenTelemetry. v2 adds optional OTel support with minimal API changes.

See VERSIONING_GUIDE.md for migration instructions and versioning workflow.

📦 Packages

Production-ready components with comprehensive observability, testing, and examples:

Package	Description	Key Features
otel	OpenTelemetry integration	Tracing, metrics, logging, unified config
config	YAML configuration with env overrides	Type-safe, validation, hot-reload
logging	Structured logging with zerolog	Context-aware, OTel integration
db	Multi-database support	PostgreSQL, MySQL, MSSQL, migrations, OTel
docker	Docker container executor	Lifecycle management, wait strategies, dual API
argo	Argo Workflows client	Kubernetes API, Argo Server, OTel, flexible config
server	HTTP server with Echo	Health checks, metrics, graceful shutdown
grpc	gRPC server with Echo gateway	H2C mode, dual protocol, observability
rest	HTTP client framework	Retries, timeouts, OTel tracing
retry	Retry with exponential backoff	Reusable operations, context-aware, OTel support
concurrent	Type-safe concurrent execution	Generics, error handling, cancellation
temporal	Temporal workflow integration	Workers, scheduling, monitoring
ssh	SSH tunneling utilities	Secure connections, port forwarding
compress	File compression utilities	ZIP, tar.gz, security validation

🚀 Quick Start

Installation

# Latest stable v1 (production)
go get github.com/jasoet/pkg

# v2 (includes OpenTelemetry)
go get github.com/jasoet/pkg/v2@v2.0.0

Basic Usage

package main

import (
    "github.com/jasoet/pkg/v2/config"
    "github.com/jasoet/pkg/v2/logging"
    "github.com/jasoet/pkg/v2/server"
    "github.com/jasoet/pkg/v2/otel"
    "github.com/labstack/echo/v4"
)

type AppConfig struct {
    Port int `yaml:"port"`
}

func main() {
    // Load configuration
    cfg, _ := config.LoadString[AppConfig](`port: 8080`)

    // Setup OpenTelemetry
    otelConfig := otel.NewConfig("my-service").
        WithTracerProvider(/* your tracer */).
        WithMeterProvider(/* your meter */)

    // Setup logging with OTel
    loggerProvider := logging.NewLoggerProvider("my-service", false)
    otelConfig.LoggerProvider = loggerProvider

    // Start HTTP server with observability
    operation := func(e *echo.Echo) {
        e.GET("/", func(c echo.Context) error {
            return c.String(200, "Hello!")
        })
    }

    shutdown := func(e *echo.Echo) {
        // cleanup
    }

    serverCfg := server.DefaultConfig(cfg.Port, operation, shutdown)
    serverCfg.OTelConfig = otelConfig
    server.StartWithConfig(serverCfg)
}

Examples

Each package includes comprehensive examples:

# Run specific package examples
go run -tags=example ./logging/examples
go run -tags=example ./db/examples
go run -tags=example ./server/examples

# Build all examples
go build -tags=example ./...

📖 Browse Package Examples

🔬 Test Coverage

Overall Coverage: 85%

Package Coverage

• concurrent (100%), otel (97%), config (95%), rest (93%), compress (86%), temporal (86%), docker (84%), server (83%), grpc (82%), logging (82%), db (79%), ssh (77%)

Run Tests

# Unit tests
task test

# Integration tests (Docker required)
task test:integration

# All tests with coverage report
task test:all
open output/coverage-all.html

🎯 Key Features

OpenTelemetry Integration

• Unified Configuration: Single config for tracing, metrics, and logging
• Automatic Instrumentation: Built-in for HTTP, gRPC, database operations
• Context Propagation: Distributed tracing across services
• Metrics Collection: Prometheus-compatible metrics

Database Support

• Multi-Database: PostgreSQL, MySQL, MSSQL with GORM
• Migrations: Automated schema management with golang-migrate
• Connection Pooling: Configurable with health monitoring
• OTel Tracing: Automatic query tracing and metrics

HTTP & gRPC Servers

• Echo Framework: Modern HTTP server with middleware support
• gRPC Gateway: Dual HTTP/gRPC protocol support with H2C mode
• Health Checks: Built-in health endpoints
• Graceful Shutdown: Proper resource cleanup

Resilient REST Client

• Retry Logic: Configurable exponential backoff
• Circuit Breaking: Fail-fast patterns
• Request Tracing: Automatic distributed tracing
• Middleware Support: Custom request/response handlers

Type-Safe Concurrency

• Go 1.25+ Generics: Type-safe parallel execution
• Error Handling: Aggregate errors from concurrent operations
• Context Support: Cancellation and timeout handling
• Resource Management: Automatic goroutine cleanup

🔧 Development

Development Commands

# Testing
# All integration test using testcontainer, docker engine required
task test               # Unit tests
task test:integration   # Integration tests (Docker required)
task test:all           # All tests with coverage

# Quality
task lint               # Run golangci-lint

🤖 AI Agent Instructions

Repository Type: Go utility library (v2) - production-ready infrastructure components with OpenTelemetry

Critical Setup:

• Ensure docker engine available and accessible from testcontainer

Architecture:

• 12 core packages: otel, config, logging, db, docker, server, grpc, rest, concurrent, temporal, ssh, compress
• Integration-ready: Packages work seamlessly together
• Examples: Each package has runnable examples with go run -tags=example ./package/examples
• Module Path: github.com/jasoet/pkg/v2 (Go v2+ semantics)

Key Development Patterns:

• OpenTelemetry: Instrumentation across all packages (otel package)
• Configuration: Type-safe YAML with environment variable overrides (config package)
• Database: Multi-database support with GORM, migrations, OTel tracing (db package)
• HTTP Server: Echo framework with health checks, metrics, graceful shutdown (server package)
• gRPC: Production-ready server with Echo gateway, H2C mode, observability (grpc package)
• REST Client: Resilient HTTP client with retries, OTel tracing (rest package)
• Logging: Zerolog with OTel log provider integration (logging package)
• Concurrency: Type-safe parallel execution with Go 1.25+ generics (concurrent package)
• Workflows: Temporal integration for distributed workflows (temporal package)

Testing Strategy:

• Coverage: 85% (unit + integration, excludes generated code)
• Unit Tests: task test (no Docker, race detection enabled)
• Integration Tests: task test:integration (testcontainers, Docker required)
• All Tests: task test:all (complete coverage, generates output/coverage-all.html)
• Assertion Library: Use github.com/stretchr/testify/assert for all test assertions
• Test Categories:
  • Unit: No build tags, no external dependencies
  • Integration: Build tag integration, uses testcontainers

Library Usage Focus:

• Emphasize zero-configuration startup
• Type safety with generics
• Production-grade features: health endpoints, metrics, observability, graceful shutdown
• OpenTelemetry as first-class citizen

Version Information:

• Current: v2.0.0 GA (includes OpenTelemetry)
• Stable v1: v1.5.0 (no OpenTelemetry, maintenance only)
• Migration Guide: See VERSIONING_GUIDE.md

📚 Package Documentation

Core Infrastructure

otel - OpenTelemetry Integration

Unified configuration for tracing, metrics, and logging.

config := otel.NewConfig("my-service").
    WithTracerProvider(tracerProvider).
    WithMeterProvider(meterProvider).
    WithLoggerProvider(loggerProvider)

tracer := config.GetTracer()
meter := config.GetMeter()
logger := config.GetLogger()

Features: Automatic instrumentation, context propagation, graceful shutdown Coverage: 97.1% | Examples | Documentation

config - Configuration Management

Type-safe YAML configuration with environment variable overrides.

type AppConfig struct {
    Server ServerConfig `yaml:"server"`
    DB     DBConfig     `yaml:"database"`
}

// Load from file
cfg, _ := config.LoadString[AppConfig](yamlContent)

// Or from string
yamlStr := `
server:
  port: 8080
database:
  host: localhost
`
cfg, _ := config.LoadString[AppConfig](yamlStr)

Features: Hot-reload, validation, environment overrides Coverage: 94.7% | Examples | Documentation

logging - Structured Logging

Zerolog-based OTel LoggerProvider with automatic trace correlation.

// Create LoggerProvider
loggerProvider := logging.NewLoggerProvider("my-service", false)

// Use with OTel config
otelCfg := &otel.Config{
    LoggerProvider: loggerProvider,
    // ... other config
}

// Or use legacy zerolog
logging.Initialize("my-service", false)
log.Info().Str("user", "john").Msg("User logged in")

Features: Context-aware, OTel log provider, performance optimized Coverage: 82.0% | Examples | Documentation

Data Access

db - Multi-Database Support

PostgreSQL, MySQL, MSSQL support with GORM and migrations.

pool, _ := db.ConnectionConfig{
    DbType:     db.Postgresql,
    Host:       "localhost",
    Port:       5432,
    Username:   "user",
    Password:   "pass",
    DbName:     "mydb",
    OTelConfig: otelConfig,
}.Pool()

// Automatic query tracing and metrics
pool.Find(&users)

Features: Connection pooling, migrations, OTel tracing, health monitoring Coverage: 79.1% | Examples | Documentation

docker - Docker Container Executor

Production-ready Docker container management with dual API styles.

// Functional options style
exec, _ := docker.New(
    docker.WithImage("nginx:alpine"),
    docker.WithPorts("80:8080"),
    docker.WithWaitStrategy(
        docker.WaitForLog("start worker processes"),
    ),
)

exec.Start(ctx)
defer exec.Terminate(ctx)

endpoint, _ := exec.Endpoint(ctx, "80/tcp")
// Use: http://localhost:8080

// Or struct-based (testcontainers-like)
req := docker.ContainerRequest{
    Image:        "postgres:16-alpine",
    ExposedPorts: []string{"5432/tcp"},
    Env: map[string]string{
        "POSTGRES_PASSWORD": "secret",
    },
    WaitingFor: docker.WaitForLog("ready to accept connections"),
}
exec, _ := docker.NewFromRequest(req)

Features: Lifecycle management, wait strategies, log streaming, dual API (functional + struct) Coverage: 83.9% | Examples | Documentation

argo - Argo Workflows Client

Production-ready Argo Workflows client with flexible configuration.

// Default kubeconfig
ctx, client, err := argo.NewClient(ctx, argo.DefaultConfig())
if err != nil {
    return err
}
defer client.Close()

// Or with functional options
ctx, client, err := argo.NewClientWithOptions(ctx,
    argo.WithKubeConfig("/path/to/kubeconfig"),
    argo.WithContext("production"),
    argo.WithOTelConfig(otelConfig),
)

// In-cluster mode
ctx, client, err := argo.NewClient(ctx, argo.InClusterConfig())

// Argo Server mode
ctx, client, err := argo.NewClientWithOptions(ctx,
    argo.WithArgoServer("https://argo-server:2746", "Bearer token"),
)

Features: Multiple connection modes, functional options, OTel support, proper error handling Examples | Documentation

HTTP & gRPC

server - HTTP Server

Echo-based HTTP server with built-in observability.

operation := func(e *echo.Echo) {
    e.GET("/health", healthHandler)
}

shutdown := func(e *echo.Echo) {
    // cleanup
}

config := server.DefaultConfig(8080, operation, shutdown)
config.OTelConfig = otelConfig
server.StartWithConfig(config)

Features: Health checks, Prometheus metrics, graceful shutdown, middleware Coverage: 83.0% | Examples | Documentation

grpc - gRPC Server

Production-ready gRPC with Echo gateway integration.

server, _ := grpc.New(
    grpc.WithGRPCPort("9090"),
    grpc.WithOTelConfig(otelConfig),
    grpc.WithServiceRegistrar(func(s *grpc.Server) {
        // Register your gRPC services
        pb.RegisterYourServiceServer(s, &YourService{})
    }),
)

server.Start()

Features: H2C mode, dual HTTP/gRPC, gateway, observability Coverage: 82.0% | Examples | Documentation

rest - HTTP Client

Resilient REST client with OTel tracing.

config := rest.Config{
    RetryCount:       3,
    RetryWaitTime:    1 * time.Second,
    RetryMaxWaitTime: 10 * time.Second,
    Timeout:          30 * time.Second,
}

client := rest.NewClient(
    rest.WithRestConfig(config),
    rest.WithOTelConfig(otelConfig),
)

response, _ := client.MakeRequestWithTrace(ctx, "GET", url, "", headers)

Features: Retries, circuit breaking, tracing, middleware support Coverage: 92.9% | Examples | Documentation

Utilities

concurrent - Type-Safe Concurrency

Generics-based parallel execution with error handling.

funcs := map[string]concurrent.Func[string]{
    "task1": func(ctx context.Context) (string, error) {
        return "result1", nil
    },
    "task2": func(ctx context.Context) (string, error) {
        return "result2", nil
    },
}

results, _ := concurrent.ExecuteConcurrently(ctx, funcs)

Features: Go 1.25+ generics, error aggregation, context support Coverage: 100% | Examples | Documentation

temporal - Workflow Orchestration

Temporal workflow integration with observability.

config := &temporal.Config{
    HostPort:  "localhost:7233",
    Namespace: "default",
}

client, _ := temporal.NewClient(config)
manager := temporal.NewScheduleManager(client)

manager.CreateWorkflowSchedule(ctx, scheduleID, workflow, schedule)

Features: Schedule management, workers, monitoring Coverage: 86.4% | Examples | Documentation

ssh - SSH Tunneling

Secure SSH tunneling and port forwarding.

config := ssh.Config{
    Host:       "remote-host",
    Port:       22,
    User:       "user",
    Password:   "password",
    RemoteHost: "db.internal",
    RemotePort: 5432,
    LocalPort:  15432,
}

tunnel := ssh.New(config)
tunnel.Start()
defer tunnel.Close()

Features: Port forwarding, connection pooling, error handling Coverage: 76.7% | Examples | Documentation

compress - File Compression

Secure file compression with validation.

// Gzip compression
sourceFile, _ := os.Open("input.txt")
outputFile, _ := os.Create("output.gz")
compress.Gz(sourceFile, outputFile)

// Tar.gz archive
outputFile, _ := os.Create("archive.tar.gz")
compress.TarGz("/path/to/directory", outputFile)

Features: ZIP, tar.gz, security validation, path traversal protection Coverage: 86.3% | Examples | Documentation

🤝 Contributing

Contributions are welcome! Please read our Contributing Guide for details.

Quick Contribution Workflow

1. Fork & Clone

   git clone https://github.com/your-username/pkg.git
   cd pkg
   

2. Setup Development Environment

   task docker:up
   task test
   

3. Create Feature Branch

   git checkout -b feature/your-feature-name
   

4. Make Changes & Test

   task test           # Unit tests
   task test:all       # Full coverage
   task lint           # Code quality
   task security       # Security check
   

5. Commit with Conventional Commits

   git commit -m "feat(package): add new feature"
   git commit -m "fix(package): resolve issue"
   git commit -m "docs: update README"
   

6. Push & Create PR

   git push origin feature/your-feature-name
   # Create pull request on GitHub
   

Commit Message Format

We use Conventional Commits:

<type>(<scope>): <description>

[optional body]

[optional footer]

Types: feat, fix, docs, style, refactor, test, chore, perf, ci Breaking Changes: Add ! after type or BREAKING CHANGE: in footer

See VERSIONING_GUIDE.md for versioning workflow and v1 to v2 migration instructions.

📈 Roadmap

✅ Completed

• Core packages (11 components)
• OpenTelemetry instrumentation
• 85% test coverage (unit + integration)
• Integration examples
• Task-based development workflow
• CI/CD pipeline with automated testing
• Comprehensive documentation
• gRPC & Protobuf support with Echo gateway
• Testcontainer-based integration tests

✅ v2.0.0 GA Released

• Review and update all package READMEs
• Review and update all example READMEs
• Ensure all examples demonstrate OTel integration
• Create fullstack OTel example application (examples/fullstack-otel)
• v2.0.0 GA release

✅ Completed (Post v2.0 GA)

• Docker Executor Package - Production-ready Docker execution helper with testcontainer-compatible API
  • Dual API: functional options + struct-based (testcontainers-like)
  • Lifecycle management: Start, Stop, Restart, Terminate, Wait
  • Wait strategies: log patterns, port listening, HTTP health checks
  • Log streaming with filtering
  • OpenTelemetry v2 instrumentation
  • 83.9% test coverage, zero lint issues

📝 Planned

• Temporal Docker Workflows - Reusable Temporal workflows for Docker container execution
  • Pre-built workflow templates for containerized jobs
  • Integration with docker executor package
  • Observability and error handling patterns

🔗 Links

• Documentation: Browse Package Docs
• Examples: All Examples
• Versioning Guide: VERSIONING_GUIDE.md
• Contributing: CONTRIBUTING.md
• Changelog: Releases
• Issues: GitHub Issues

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

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