package main import ( "errors" "gopkg.in/yaml.v2" "io/ioutil" "log" "os" ) // Config type is contains all provided user configuration type Config struct { CheckInterval int64 `yaml:"check_interval"` Monitors []*Monitor Alerts map[string]*Alert } // IsValid checks config validity and returns true if valid func (config Config) IsValid() (isValid bool) { isValid = true // Validate monitors if config.Monitors == nil || len(config.Monitors) == 0 { log.Printf("ERROR: Invalid monitor configuration: Must provide at least one monitor") isValid = false } for _, monitor := range config.Monitors { if !monitor.IsValid() { log.Printf("ERROR: Invalid monitor configuration: %s", monitor.Name) isValid = false } } // Validate alerts if config.Alerts == nil || len(config.Alerts) == 0 { log.Printf("ERROR: Invalid alert configuration: Must provide at least one alert") isValid = false } for _, alert := range config.Alerts { if !alert.IsValid() { log.Printf("ERROR: Invalid alert configuration: %s", alert.Name) isValid = false } } return } // Init performs extra initialization on top of loading the config from file func (config *Config) Init() (err error) { for name, alert := range config.Alerts { alert.Name = name if err = alert.BuildTemplates(); err != nil { return } } return } // LoadConfig will read config from the given path and parse it func LoadConfig(filePath string) (config Config, err error) { data, err := ioutil.ReadFile(filePath) if err != nil { return } // TODO: Decide if this is better expanded here, or only when executing envExpanded := os.ExpandEnv(string(data)) err = yaml.Unmarshal([]byte(envExpanded), &config) if err != nil { return } log.Printf("config:\n%v\n", config) if !config.IsValid() { err = errors.New("Invalid configuration") return } // Finish initializing configuration err = config.Init() return }