feat: initial implementation of go-tlog with examples, CI and README

Initial project setup:

- Added logger core (level, format, stacktrace, internal outputs)
- Added tests for core logger functionality
- Added examples (stdout, stderr, file)
- Added GitHub Actions CI workflow
- Added README and LICENSE (BSD 2-Clause)
- Added .golangci.yml and .gitignore

Author: vakhov

.github/workflows/ci.yml

@@ -0,0 +1,28 @@
+name: CI
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ '**' ]
+  workflow_dispatch:
+
+jobs:
+  test:
+    name: Go tests
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: '1.24.x'
+          check-latest: true
+
+      - name: Download deps
+        run: go mod download
+
+      - name: Run tests
+        run: make test

.gitignore

@@ -0,0 +1,4 @@
+# IDE
+.idea
+
+coverage.out

.golangci.yml

@@ -0,0 +1,48 @@
+run:
+  timeout: 5m
+  modules-download-mode: readonly
+
+issues:
+  exclude-use-default: false
+  max-same-issues: 0
+  max-issues-per-linter: 0
+
+linters:
+  enable:
+    - govet
+    - staticcheck
+    - revive
+    - errcheck
+    - gosimple
+    - ineffassign
+    - unused
+    - typecheck
+    - gofmt
+    - goimports
+    - misspell
+    - gocritic
+
+linters-settings:
+  revive:
+    severity: warning
+    rules:
+      - name: unused-parameter
+      - name: unreachable-code
+      - name: indent-error-flow
+      - name: exported
+      - name: blank-imports
+      - name: var-declaration
+      - name: if-return
+
+  misspell:
+    locale: US
+
+  goimports:
+    local-prefixes: github.com/tarantool/go-tlog
+
+# Skip linters on example files and any generated code
+exclude-rules:
+  - path: ^_examples/
+    linters: [revive, staticcheck, govet, gocritic]
+  - path: \.pb\.go$|_gen\.go$
+    linters: [all]

CHANGELOG.md

@@ -0,0 +1,14 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
+and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+
+### Added
+
+### Changed
+
+### Fixed

LICENCE

@@ -0,0 +1,25 @@
+BSD 2-Clause License
+
+Copyright (c) 2025, Tarantool AUTHORS
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Makefile

@@ -0,0 +1,50 @@
+# Default Go toolchain
+GO              ?= go
+GOLANGCI_LINT   ?= golangci-lint
+PKG             := github.com/tarantool/go-tlog
+
+.PHONY: all test test-race test-coverage lint fmt tidy examples help
+
+all: test
+
+## Run tests
+test:
+	$(GO) test ./...
+
+## Run tests with race detector
+test-race:
+	$(GO) test -race ./...
+
+## Run tests with coverage
+test-coverage:
+	$(GO) test -covermode=atomic -coverprofile=coverage.out ./...
+
+## Run golangci-lint
+lint:
+	$(GOLANGCI_LINT) run ./...
+
+## Format source code
+fmt:
+	$(GO) fmt ./...
+
+## Tidy go.mod / go.sum
+tidy:
+	$(GO) mod tidy
+
+## Run all _examples to ensure they compile and run without panic
+examples:
+	$(GO) run ./_examples/stdout
+	$(GO) run ./_examples/stderr >/dev/null 2>&1 || true
+	$(GO) run ./_examples/file
+	$(GO) run ./_examples/multi
+
+## Show available targets
+help:
+	@echo "Available targets:"
+	@echo "  make test           - run tests"
+	@echo "  make test-race      - run tests with -race"
+	@echo "  make test-coverage  - run tests with coverage"
+	@echo "  make lint           - run golangci-lint"
+	@echo "  make fmt            - format sources (gofmt)"
+	@echo "  make tidy           - go mod tidy"
+	@echo "  make examples       - run all examples"

README.md

@@ -1 +1,189 @@
+[![CI](https://github.com/tarantool/go-tlog/actions/workflows/ci.yml/badge.svg)](https://github.com/tarantool/go-tlog/actions/workflows/ci.yml) •
+[Telegram EN](https://t.me/tarantool) •
+[Telegram RU](https://t.me/tarantoolru)
+
+---
+
+<p href="https://www.tarantool.io">
+	<img src="https://github.com/tarantool.png" align="right" width=250>
+</p>
+
 # go-tlog
+
+`go-tlog` is a lightweight and configurable logging library for Go applications.  
+It provides structured logging with multiple output destinations, flexible formatting,
+and fine-grained log-level control.
+
+---
+
+## Features
+
+- Simple setup via configuration struct
+- Text or JSON output formats
+- Multiple output targets: **stdout**, **stderr**, **files**
+- Log levels: `Trace`, `Debug`, `Info`, `Warn`, `Error`
+- Automatic timestamp, source file, and line number
+- Stacktrace for errors
+
+---
+
+## Installation
+
+```bash
+go get github.com/tarantool/go-tlog@latest
+```
+
+Then import:
+
+```go
+import "github.com/tarantool/go-tlog"
+```
+
+---
+
+## Quick start
+
+```go
+package main
+
+import "github.com/tarantool/go-tlog"
+
+func main() {
+	log, err := tlog.New(tlog.Opts{
+		Level:  tlog.LevelInfo,
+		Format: tlog.FormatText,
+		Path:   "stdout",
+	})
+	if err != nil {
+		panic(err)
+	}
+	defer log.Close()
+
+	logger := log.Logger().With(tlog.String("component", "demo"))
+	logger.Info("service started", "port", 8080)
+	logger.Error("failed to connect", "err", "timeout")
+}
+```
+
+Output:
+
+```
+2025-11-10T13:30:01+05:00 INFO service started component=demo port=8080
+2025-11-10T13:30:01+05:00 ERROR failed to connect err=timeout component=demo stacktrace="..."
+```
+
+---
+
+## Configuration
+
+### `type Opts`
+
+```go
+type Opts struct {
+    Level  Level  // minimal log level
+    Format Format // FormatText or FormatJSON
+    Path   string // comma-separated outputs: "stdout,/var/log/app.log"
+}
+```
+
+### Main API
+
+| Function         | Description                              |
+|------------------|------------------------------------------|
+| `tlog.New(opts)` | Create a new logger                      |
+| `Logger()`       | Return the underlying logger for use     |
+| `Close()`        | Flush buffers and close file descriptors |
+
+---
+
+## Log levels
+
+| Level   | When to use                                 |
+|---------|---------------------------------------------|
+| `Trace` | Low-level tracing                           |
+| `Debug` | Debugging information                       |
+| `Info`  | Normal operational messages                 |
+| `Warn`  | Non-fatal warnings                          |
+| `Error` | Errors and exceptions (includes stacktrace) |
+
+---
+
+## Output formats
+
+| Format       | Example                                                       |
+|--------------|---------------------------------------------------------------|
+| `FormatText` | `2025-11-10T13:31:45+05:00 INFO message key=value`            |
+| `FormatJSON` | `{"time":"...","level":"INFO","msg":"message","key":"value"}` |
+
+---
+
+## Output destinations
+
+You can specify multiple targets separated by commas:
+
+```go
+Path: "stdout,/tmp/app.log"
+```
+
+Supported targets:
+
+- `stdout`
+- `stderr`
+- File paths (created automatically if not present)
+
+---
+
+## Examples
+
+Ready-to-run examples are located in the `_examples/` directory:
+
+```
+_examples/
+ ├── stdout/
+ │   └── main.go
+ ├── stderr/
+ │   └── main.go
+ ├── file/
+ │   └── main.go
+ └── multi/
+     └── main.go
+```
+
+Run examples:
+
+```bash
+# Example 1 — log to STDOUT in text format
+go run ./_examples/stdout
+
+# Example 2 — log to STDERR in JSON format
+# Redirect stderr to a file and inspect its contents
+go run ./_examples/stderr 2> logs.json
+cat logs.json
+
+# Example 3 — log to a file in /tmp directory
+# The file will be created automatically if it doesn’t exist
+go run ./_examples/file
+cat /tmp/tlog_demo/app.log
+
+# Example 4 — log to multiple destinations (stdout + file)
+# This writes the same log entry both to console and to /tmp/tlog_multi/app.log
+go run ./_examples/multi
+cat /tmp/tlog_multi/app.log
+```
+
+Each example demonstrates different combinations of Path, Format, and Level,
+including how to log to multiple outputs at the same time.
+
+---
+
+## Testing
+
+```bash
+go test ./...
+```
+
+---
+
+## License
+
+BSD 2-Clause License — see [LICENSE](LICENSE)

_examples/file/main.go

@@ -0,0 +1,27 @@
+package main
+
+import (
+	"log/slog"
+	"os"
+
+	"github.com/tarantool/go-tlog"
+)
+
+func main() {
+	_ = os.MkdirAll("/tmp/tlog_demo", 0755)
+
+	l, err := tlog.New(tlog.Opts{
+		Level:  tlog.LevelInfo,
+		Format: tlog.FormatText,
+		Path:   "/tmp/tlog_demo/app.log",
+	})
+	if err != nil {
+		panic(err)
+	}
+	defer l.Close()
+
+	log := l.Logger().With(slog.String("mode", "file"))
+	log.Info("logging to file", "path", "/tmp/tlog_demo/app.log")
+	log.Warn("network delay", "ms", 250)
+	log.Error("write failed", "err", "disk quota exceeded")
+}