add support for multiple domains

Author: Sai Kiran Anagani

.gitignore

@@ -4,7 +4,8 @@ A simple script in Go language to automatically update Digital ocean DNS records
 ## requirements
 Requires Git and Go for building.
 
-Requires that the record already exists in DigitalOcean's DNS.
+Requires that the record already exists in DigitalOcean's DNS so that it can be updated.
+(manually find your IP and add it to DO's DNS it will later be updated)
 
 ## Usage
 ```bash
@@ -15,11 +16,24 @@ create a file ".digitalocean-dynamic-ip.json"(dot prefix to hide the file) and p
 ```json
 {
   "apikey": "samplekeydasjkdhaskjdhrwofihsamplekey",
-  "domain": "example.com",
-  "records": [
+  "domains": [
     {
-      "name": "subdomain",
-      "type": "A"
+      "domain": "example.com",
+      "records": [
+        {
+          "name": "subdomainOrRecord",
+          "type": "A"
+        }
+      ]
+    },
+    {
+      "domain": "example2.com",
+      "records": [
+        {
+          "name": "subdomainOrRecord2",
+          "type": "A"
+        }
+      ]
     }
   ]
 }

LICENSE.md

@@ -13,15 +13,20 @@ import (
 
 func checkError(err error) {
 	if err != nil {
-		panic(err)
+		log.Fatal(err)
 	}
 }
 
 // ClientConfig : configuration json
 type ClientConfig struct {
-	APIKey string      `json:"apiKey"`
-	Domain string      `json:"domain"`
-	Record []DNSRecord `json:"records"`
+	APIKey  string   `json:"apiKey"`
+	Domains []Domain `json:"domains"`
+}
+
+// Domain : domains to be changed
+type Domain struct {
+	Domain  string      `json:"domain"`
+	Records []DNSRecord `json:"records"`
 }
 
 // DNSRecord : Modifyiable DNS record
@@ -37,60 +42,79 @@ type DOResponse struct {
 	DomainRecords []DNSRecord `json:"domain_records"`
 }
 
-func main() {
+//GetConfig : get configuration file ~/.digitalocean-dynamic-ip.json
+func GetConfig() ClientConfig {
 	homeDirectory, err := homedir.Dir()
 	checkError(err)
 	getfile, err := ioutil.ReadFile(homeDirectory + "/.digitalocean-dynamic-ip.json")
 	checkError(err)
 	var config ClientConfig
 	json.Unmarshal(getfile, &config)
 	checkError(err)
+	return config
+}
 
-	// check current local ip
-
+//CheckLocalIP : get current IP of server.
+func CheckLocalIP() string {
 	currentIPRequest, err := http.Get("https://diagnostic.opendns.com/myip")
 	checkError(err)
 	defer currentIPRequest.Body.Close()
 	currentIPRequestParse, err := ioutil.ReadAll(currentIPRequest.Body)
 	checkError(err)
-	currentIP := string(currentIPRequestParse)
-
-	// get current dns record ip
+	return string(currentIPRequestParse)
+}
 
+//GetDomainRecords : Get DNS records of current domain.
+func GetDomainRecords(apiKey string, domain string) DOResponse {
 	client := &http.Client{}
 	request, err := http.NewRequest("GET",
-		"https://api.digitalocean.com/v2/domains/"+string(config.Domain)+"/records",
+		"https://api.digitalocean.com/v2/domains/"+domain+"/records",
 		nil)
 	checkError(err)
 	request.Header.Add("Content-type", "Application/json")
-	request.Header.Add("Authorization", "Bearer "+string(config.APIKey))
+	request.Header.Add("Authorization", "Bearer "+apiKey)
 	response, err := client.Do(request)
 	checkError(err)
 	defer response.Body.Close()
 	body, err := ioutil.ReadAll(response.Body)
-	var jsonResponse DOResponse
-	e := json.Unmarshal(body, &jsonResponse)
+	var jsonDOResponse DOResponse
+	e := json.Unmarshal(body, &jsonDOResponse)
 	checkError(e)
+	return jsonDOResponse
+}
 
-	// update ip by matching dns records and config
-
-	for _, record := range jsonResponse.DomainRecords {
-		for _, configRecord := range config.Record {
-			if configRecord.Name == record.Name && configRecord.Type == record.Type && currentIP != record.Data {
-				update := []byte(`{"type":"` + configRecord.Type + `","data":"` + currentIP + `"}`)
+// UpdateRecords : Update DNS records of domain
+func UpdateRecords(apiKey string, domain string, currentIP string, currentRecords DOResponse, toUpdateRecords []DNSRecord) {
+	for _, currentRecord := range currentRecords.DomainRecords {
+		for _, toUpdateRecord := range toUpdateRecords {
+			if toUpdateRecord.Name == currentRecord.Name && toUpdateRecord.Type == currentRecord.Type && currentIP != currentRecord.Data {
+				update := []byte(`{"type":"` + toUpdateRecord.Type + `","data":"` + currentIP + `"}`)
 				client := &http.Client{}
 				request, err := http.NewRequest("PUT",
-					"https://api.digitalocean.com/v2/domains/"+string(config.Domain)+"/records/"+strconv.FormatInt(int64(record.ID), 10),
+					"https://api.digitalocean.com/v2/domains/"+domain+"/records/"+strconv.FormatInt(int64(currentRecord.ID), 10),
 					bytes.NewBuffer(update))
 				checkError(err)
 				request.Header.Set("Content-Type", "application/json")
-				request.Header.Add("Authorization", "Bearer "+string(config.APIKey))
+				request.Header.Add("Authorization", "Bearer "+apiKey)
 				response, err := client.Do(request)
 				checkError(err)
 				defer response.Body.Close()
 				body, err := ioutil.ReadAll(response.Body)
-				log.Printf("DO update response for %s: %s", record.Name, string(body))
+				log.Printf("DO update response for %s: %s\n", currentRecord.Name, string(body))
 			}
 		}
 	}
 }
+
+func main() {
+	config := GetConfig()
+	currentIP := CheckLocalIP()
+
+	for _, domains := range config.Domains {
+		domainName := domains.Domain
+		apiKey := config.APIKey
+		currentDomainRecords := GetDomainRecords(apiKey, domainName)
+		log.Println(domainName)
+		UpdateRecords(apiKey, domainName, currentIP, currentDomainRecords, domains.Records)
+	}
+}

README.md

@@ -1,10 +1,23 @@
 {
   "apikey": "samplekeydasjkdhaskjdhrwofihsamplekey",
-  "domain": "example.com",
-  "records": [
+  "domains": [
     {
-      "name": "subdomain",
-      "type": "A"
+      "domain": "example.com",
+      "records": [
+        {
+          "name": "subdomainOrRecord",
+          "type": "A"
+        }
+      ]
+    },
+    {
+      "domain": "example2.com",
+      "records": [
+        {
+          "name": "subdomainOrRecord2",
+          "type": "A"
+        }
+      ]
     }
   ]
 }