Initial commit: Project foundation

- Backend: Go API server with Gin framework
- Frontend: React setup (placeholder)
- ML Service: Python FastAPI skeleton
- Docker Compose: Full stack configuration
- Database: PostgreSQL schema with migrations
- Documentation: Implementation plan and README

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

backend/internal/config/config.go

@@ -0,0 +1,106 @@
+package config
+
+import (
+	"fmt"
+	"os"
+	"time"
+
+	"gopkg.in/yaml.v3"
+)
+
+type Config struct {
+	Server       ServerConfig       `yaml:"server"`
+	Database     DatabaseConfig     `yaml:"database"`
+	VictoriaLogs VictoriaLogsConfig `yaml:"victorialogs"`
+	VMAlert      VMAlertConfig      `yaml:"vmalert"`
+	MLService    MLServiceConfig    `yaml:"ml_service"`
+	Auth         AuthConfig         `yaml:"auth"`
+	RateLimiting RateLimitingConfig `yaml:"rate_limiting"`
+}
+
+type ServerConfig struct {
+	Port         int           `yaml:"port"`
+	ReadTimeout  time.Duration `yaml:"read_timeout"`
+	WriteTimeout time.Duration `yaml:"write_timeout"`
+}
+
+type DatabaseConfig struct {
+	Host           string `yaml:"host"`
+	Port           int    `yaml:"port"`
+	Name           string `yaml:"name"`
+	User           string `yaml:"user"`
+	Password       string `yaml:"password"`
+	MaxConnections int    `yaml:"max_connections"`
+}
+
+type VictoriaLogsConfig struct {
+	URL          string        `yaml:"url"`
+	Timeout      time.Duration `yaml:"timeout"`
+	MaxQuerySize int           `yaml:"max_query_size"`
+}
+
+type VMAlertConfig struct {
+	URL            string `yaml:"url"`
+	RulesDir       string `yaml:"rules_dir"`
+	ReloadEndpoint string `yaml:"reload_endpoint"`
+}
+
+type MLServiceConfig struct {
+	URL     string        `yaml:"url"`
+	Timeout time.Duration `yaml:"timeout"`
+}
+
+type AuthConfig struct {
+	JWTSecret             string        `yaml:"jwt_secret"`
+	AccessTokenDuration   time.Duration `yaml:"access_token_duration"`
+	RefreshTokenDuration  time.Duration `yaml:"refresh_token_duration"`
+}
+
+type RateLimitingConfig struct {
+	Enabled            bool           `yaml:"enabled"`
+	RequestsPerMinute  map[string]int `yaml:"requests_per_minute"`
+}
+
+// Load loads configuration from YAML file and environment variables
+func Load(configPath string) (*Config, error) {
+	data, err := os.ReadFile(configPath)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read config file: %w", err)
+	}
+
+	// Expand environment variables in config
+	expandedData := []byte(os.ExpandEnv(string(data)))
+
+	var cfg Config
+	if err := yaml.Unmarshal(expandedData, &cfg); err != nil {
+		return nil, fmt.Errorf("failed to parse config: %w", err)
+	}
+
+	// Validate required fields
+	if err := cfg.validate(); err != nil {
+		return nil, fmt.Errorf("config validation failed: %w", err)
+	}
+
+	return &cfg, nil
+}
+
+func (c *Config) validate() error {
+	if c.Database.Password == "" {
+		return fmt.Errorf("database password is required")
+	}
+	if c.Auth.JWTSecret == "" {
+		return fmt.Errorf("JWT secret is required")
+	}
+	if len(c.Auth.JWTSecret) < 32 {
+		return fmt.Errorf("JWT secret must be at least 32 characters")
+	}
+	return nil
+}
+
+// GetDSN returns the PostgreSQL connection string
+func (c *DatabaseConfig) GetDSN() string {
+	return fmt.Sprintf(
+		"host=%s port=%d user=%s password=%s dbname=%s sslmode=disable",
+		c.Host, c.Port, c.User, c.Password, c.Name,
+	)
+}