Doc config.go

src/metrics-alerting/config/config.go

 	"gopkg.in/yaml.v2"
 )
 
+// MailSettings represent the settings used to send email alerts
 type MailSettings struct {
-	// Sender of the alert emails
+	// Sender of the email alerts
 	Sender string `yaml:"sender"`
-	// Settings to connect to the mail server
+	// SMTP represent the settings needed to connect to the mail server
 	SMTP SMTPSettings `yaml:"smtp"`
 }
 
+// SMTPSettings represent the settings needed to connect to the mail server
 type SMTPSettings struct {
 	// Host of the mail server
 	Host string `yaml:"host"`
 	Password string `yaml:"password"`
 }
 
+// ScriptDataSource represent the configuration structure for providing external
+// data to iterate over. Optional.
 type ScriptDataSource struct {
 	// Type of the data source (either "plain" or "file")
 	Source string `yaml:"source"`
 	Value []string `yaml:"value"`
 }
 
+// Script represents an instance of a script.
 type Script struct {
-	// An identifying key for the script
+	// Key is an identifying key for the script
 	Key string `yaml:"key"`
-	// The script to run on Warp10
+	// Script is the script to run on Warp10
 	Script string `yaml:"script"`
-	// The type of the value returned by the script
+	// Type of the value returned by the script
 	Type string `yaml:"type"`
-	// Value above which an action is required, only required if the type is
-	// "number"
+	// Threshold is the value above which an action is required, only required
+	// if the type is "number"
 	Threshold float64 `yaml:"threshold,omitempty"`
-	// The action to take (either "http" or "email")
+	// Action identifies the action to take (either "http" or "email")
 	Action string `yaml:"action"`
-	// The action's target
+	// Target is the action's target
 	Target string `yaml:"target"`
-	// The labels that will be mentioned in the email subject, only required if
-	// the action is "email"
+	// IdentifyingLabels represents a list of labels that will be mentioned in
+	// the email subject. Optional.
 	IdentifyingLabels []string `yaml:"identifying_labels,omitempty"`
-	// Source/value of the data to use in the script
+	// ScriptDataSource represents the source/value of the data to use in the script
 	ScriptDataSource ScriptDataSource `yaml:"script_data,omitempty"`
-	// Loaded data
+	// ScriptData represents loaded data, which isn't directly filled by parsing
+	// the configuration file, but rather by reading it from ScriptDataSource
 	ScriptData map[string][]string
 }
 
+// Config represents the global configuration of the app.
 type Config struct {
-	// Settings to send email alerts, only required if the action of at least 1
-	// script is "email"
-	Mail MailSettings `yaml:"mail,omitempty"`
-	// Full URL to Warp10's /exec
+	// Mail represents the settings needed to send email alerts. Only required
+	// if the action of at least 1 script is "email"
+	Mail *MailSettings `yaml:"mail,omitempty"`
+	// Warp10Exec represents the full URL to Warp10's /exec
 	Warp10Exec string `yaml:"warp10_exec"`
-	// Warp10 read token
+	// ReadToken represents Warp10's read token
 	ReadToken string `yaml:"token"`
-	// WarpScripts to run, with an identifier as its key
+	// Script represents the WarpScripts to run
 	Scripts []Script `yaml:"scripts"`
 }
 
+// Load parses the configuration file and load external data if needed.
+// Returns an error if something went wrong when reading or parsing the
+// configuration file, or reading the external data file if any.
 func (cfg *Config) Load(filePath string) (err error) {
 	content, err := ioutil.ReadFile(filePath)
 	if err != nil {