add slack backend

backends/slack.go

@@ -0,0 +1,70 @@
+package backends
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"net/http"
+)
+
+func init() {
+	backends["slack"] = NewSlack()
+}
+
+type SlackConfig struct {
+	Webhook string  `mapstructure:"webhook" validate:"required"`
+	Color   *string `mapstructure:"color" validate:"omitempty,hexcolor"`
+}
+
+type Slack struct {
+}
+
+func NewSlack() BackendInterface {
+	return &Slack{}
+}
+
+func (*Slack) GetConfig() interface{} {
+	return SlackConfig{}
+}
+
+func (*Slack) Send(configIface interface{}, title string, message string, status *bool) error {
+	config, ok := configIface.(SlackConfig)
+	if !ok {
+		return fmt.Errorf("invalid config")
+	}
+	var color string
+	if config.Color != nil {
+		color = *config.Color
+	} else if status != nil {
+		if *status {
+			color = "good"
+		} else {
+			color = "danger"
+		}
+	} else {
+		color = "#ffffff"
+	}
+
+	body := map[string]interface{}{
+		"attachments": []map[string]interface{}{
+			{
+				"title": title,
+				"text":  message,
+				"color": color,
+			},
+		},
+	}
+	jsonBody, err := json.Marshal(body)
+	if err != nil {
+		return err
+	}
+	res, err := http.Post(config.Webhook, "application/json", bytes.NewBuffer(jsonBody))
+	if err != nil {
+		return err
+	}
+	if res.StatusCode < 200 || res.StatusCode >= 300 {
+		return fmt.Errorf("slack: %s", res.Status)
+	}
+
+	return nil
+}