How do I load configuration from YAML and env vars in Go?

Loading configuration in Go can be achieved easily using YAML files alongside environment variables. This approach allows you to manage your application settings in a structured way, improving maintainability and clarity.

Example Code


        package main
        
        import (
            "encoding/json"
            "io/ioutil"
            "log"
            "os"
            "gopkg.in/yaml.v2"
        )

        type Config struct {
            Database DatabaseConfig `yaml:"database"`
            Port     int            `yaml:"port"`
        }

        type DatabaseConfig struct {
            Host     string `yaml:"host"`
            Username string `yaml:"username"`
            Password string `yaml:"password"`
        }

        func LoadConfig() (*Config, error) {
            var config Config
            
            // Load from YAML file
            yamlFile, err := ioutil.ReadFile("config.yaml")
            if err != nil {
                return nil, err
            }
            err = yaml.Unmarshal(yamlFile, &config)
            if err != nil {
                return nil, err
            }

            // Override with environment variables if set
            if envPort := os.Getenv("APP_PORT"); envPort != "" {
                fmt.Sscanf(envPort, "%d", &config.Port)
            }
            if envDbHost := os.Getenv("DB_HOST"); envDbHost != "" {
                config.Database.Host = envDbHost
            }
            if envDbUser := os.Getenv("DB_USERNAME"); envDbUser != "" {
                config.Database.Username = envDbUser
            }
            if envDbPass := os.Getenv("DB_PASSWORD"); envDbPass != "" {
                config.Database.Password = envDbPass
            }

            return &config, nil
        }

        func main() {
            config, err := LoadConfig()
            if err != nil {
                log.Fatalf("Failed to load config: %v", err)
            }
            log.Printf("Configuration Loaded: %+v", config)
        }

How do I load configuration from YAML and env vars in Go?

Example Code

Popular Topics

Recent Languages

How do I load configuration from YAML and env vars in Go?

Example Code

Related Questions

Popular Topics

Recent Languages