From eec9e9a8810cde642b3940acb10f3b9a060a50f6 Mon Sep 17 00:00:00 2001
From: Kent Hua <pitchdarkice@gmail.com>
Date: Thu, 2 Jul 2020 06:14:57 +0000
Subject: [PATCH] add slack support for notification

---
 README.md   | 18 ++++++++++++++
 settings.go | 10 ++++++++
 utils.go    | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 96 insertions(+)

diff --git a/README.md b/README.md
index fb3a84d..a2084c9 100644
--- a/README.md
+++ b/README.md
@@ -405,6 +405,24 @@ Update config file and provide your Telegram options, a notification message wil
 ```
 Markdown is supported in message template, and use `%0A` for newline.
 
+### Slack notification support
+
+Update config file and provide your Slack options, a notification message will be sent to your slack channel once the IP is changed and updated.  
+
+```json
+  "notify": {
+    "slack": {
+      "enabled": true,
+      "bot_api_token": "xoxb-xxx",
+      "channel": "your_channel",
+      "message_template": "Domain *{{ .Domain }}* is updated to \n{{ .CurrentIP }}",
+      "use_proxy": false
+    },
+  }
+```
+Markdown is supported in message template, and use `\n` for newline.
+
+
 ### SOCKS5 proxy support
 
 You can also use SOCKS5 proxy, just fill SOCKS5 address to the ```socks5_proxy``` item:
diff --git a/settings.go b/settings.go
index 4443580..8827073 100644
--- a/settings.go
+++ b/settings.go
@@ -12,6 +12,15 @@ type Domain struct {
 	SubDomains []string `json:"sub_domains"`
 }
 
+// Notify struct for slack notification
+type SlackNotify struct {
+	Enabled     bool   `json:"enabled"`
+	BotApiToken   string `json:"bot_api_token"`
+	Channel      string `json:"channel"`
+	MsgTemplate string `json:"message_template"`
+	UseProxy    bool   `json:"use_proxy"`
+}
+
 // Notify struct for telegram notification
 type TelegramNotify struct {
 	Enabled     bool   `json:"enabled"`
@@ -35,6 +44,7 @@ type MailNotify struct {
 type Notify struct {
 	Telegram TelegramNotify `json:"telegram"`
 	Mail     MailNotify     `json:"mail"`
+	Slack	 SlackNotify	`json:"slack"`
 }
 
 // Settings struct
diff --git a/utils.go b/utils.go
index d74c03f..8489152 100644
--- a/utils.go
+++ b/utils.go
@@ -10,6 +10,7 @@ import (
 	"log"
 	"net"
 	"net/http"
+	"net/url"
 	"strings"
 
 	dnsResolver "github.com/TimothyYe/godns/resolver"
@@ -321,6 +322,69 @@ func SendMailNotify(configuration *Settings, domain, currentIP string) error {
 	return nil
 }
 
+// SendSlack sends slack if IP is changed
+func SendSlackNotify(configuration *Settings, domain, currentIP string) error {
+	if !configuration.Notify.Slack.Enabled {
+		return nil
+	}
+
+	if configuration.Notify.Slack.BotApiToken == "" {
+		return errors.New("bot api token cannot be empty")
+	}
+
+	if configuration.Notify.Slack.Channel == "" {
+		return errors.New("channel cannot be empty")
+	}
+	client := GetHttpClient(configuration, configuration.Notify.Slack.UseProxy)
+	tpl := configuration.Notify.Slack.MsgTemplate
+	if tpl == "" {
+		tpl = "_Your IP address is changed to_\n\n*{{ .CurrentIP }}*\n\nDomain *{{ .Domain }}* is updated"
+	}
+
+	msg := buildTemplate(currentIP, domain, tpl)
+	
+	var response *http.Response
+	var err error
+
+	formData := url.Values{
+		"token": {configuration.Notify.Slack.BotApiToken},
+		"channel": {configuration.Notify.Slack.Channel},
+		"text": {msg},
+	}
+
+	response, err = client.PostForm("https://slack.com/api/chat.postMessage", formData)
+
+	if err != nil {
+		return err
+	}
+
+	defer response.Body.Close()
+
+	body, _ := ioutil.ReadAll(response.Body)
+	type ResponseParameters struct {
+		MigrateToChatID int64 `json:"migrate_to_chat_id"` // optional
+		RetryAfter      int   `json:"retry_after"`        // optional
+	}
+	type APIResponse struct {
+		Ok          bool                `json:"ok"`
+		Result      json.RawMessage     `json:"result"`
+		ErrorCode   int                 `json:"error_code"`
+		Description string              `json:"description"`
+		Parameters  *ResponseParameters `json:"parameters"`
+	}
+	var resp APIResponse
+	err = json.Unmarshal([]byte(body), &resp)
+	if err != nil {
+		fmt.Println("error:", err)
+		return errors.New("Failed to parse response")
+	}
+	if !resp.Ok {
+		return errors.New(resp.Description)
+	}
+
+ 	return nil
+}
+
 // SendNotify sends notify if IP is changed
 func SendNotify(configuration *Settings, domain, currentIP string) error {
 	err := SendTelegramNotify(configuration, domain, currentIP)
@@ -331,6 +395,10 @@ func SendNotify(configuration *Settings, domain, currentIP string) error {
 	if err != nil {
 		log.Println("Send email notification with error:", err.Error())
 	}
+	err = SendSlackNotify(configuration, domain, currentIP)
+	if err != nil {
+		log.Println("Send slack notification with error:", err.Error())
+	}
 	return nil
 }