Config Module 📋

config.go 🛠️

Purpose

The config.go file defines the application's configuration and provides utilities to load it from a YAML file. This module is essential for managing dynamic settings across various components.

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Key Components 🔑

1. Message Struct

• Purpose: Represents notification messages used across the system.
• Key Features:
• Implements sql.Scanner to parse JSON from the database into a Message struct.
• Implements driver.Valuer to convert the Message struct into JSON for database storage.
• Example:

  type Message struct {
      Title string `json:"title"`
      Text  string `json:"text"`
  }
  
  func (m *Message) Scan(value interface{}) error {
      return json.Unmarshal(value.([]byte), m)
  }
  
  func (m Message) Value() (driver.Value, error) {
      return json.Marshal(m)
  }
  

2. ScheduledJob Struct

• Purpose: Defines the fields required for scheduling notification jobs.
• Key Fields:
• ID: Unique identifier for the job.
• Name: Name of the job.
• NotificationType: Type of notification (e.g., email, Slack).
• Recipient: Target recipient.
• Message: Message content in Message struct format.
• ScheduleExpression: Cron expression for job timing.
• Example:

  type ScheduledJob struct {
      ID                 int       `json:"id"`
      Name               string    `json:"name"`
      NotificationType   string    `json:"notification_type"`
      Recipient          string    `json:"recipient"`
      Message            Message   `json:"message"`
      ScheduleExpression string    `json:"schedule_expression"`
  }
  

3. Notifier Interface

• Purpose: Defines the methods that custom notifiers must implement.
• Methods:
• Name() string: Returns the name of the notifier.
• Type() string: Returns the type of the notifier.
• Notify(message *Message) error: Sends a notification based on the provided message.
• Example Implementation:

  type Notifier interface {
      Name() string
      Type() string
      Notify(message *Message) error
  }
  

4. LoadConfig Function

• Purpose: Reads and parses the configuration file into a structured Config object.
• Steps:
• Opens the config.yaml file.
• Parses its content into a Config struct.
• Returns the structured configuration for use across the application.
• Example:

  func LoadConfig(path string) (*Config, error) {
      data, err := ioutil.ReadFile(path)
      if err != nil {
          return nil, err
      }
      var config Config
      err = yaml.Unmarshal(data, &config)
      if err != nil {
          return nil, err
      }
      return &config, nil
  }
  

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Config Struct 📦

Purpose

Encapsulates the entire configuration for the application, including database settings, notification channels, and scheduler options.

Key Fields

• Database Config:
• Host, Port, User, Password, Name
• Channels Config:
• Email, Slack, SMS, Webhook configurations
• Scheduler Flag:
• Enables or disables the job scheduler.

Example

type Config struct {
    Database  DatabaseConfig    `yaml:"database"`
    Channels  map[string]ChannelConfig `yaml:"channels"`
    Scheduler bool              `yaml:"scheduler"`
}

type DatabaseConfig struct {
    Host     string `yaml:"host"`
    Port     int    `yaml:"port"`
    User     string `yaml:"user"`
    Password string `yaml:"password"`
    Name     string `yaml:"name"`
}

type ChannelConfig struct {
    Enabled    bool   `yaml:"enabled"`
    Host       string `yaml:"host"`
    Port       int    `yaml:"port"`
    Username   string `yaml:"username"`
    Password   string `yaml:"password"`
    WebhookURL string `yaml:"webhook_url"`
}

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Example Flow 🔄

1. Load Configuration:
2. The application reads config.yaml on startup.
3. Parses the YAML file into a structured Config object.
4. Use Configuration:
5. Components access configuration values directly from the Config object.
6. Example: go dbConnStr := fmt.Sprintf("%s:%s@tcp(%s:%d)/%s", cfg.Database.User, cfg.Database.Password, cfg.Database.Host, cfg.Database.Port, cfg.Database.Name, )

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This documentation provides a detailed explanation of config.go, highlighting its essential role in managing the application’s dynamic settings. 🛠️ Happy configuring!