Merge pull request #7 from cdzombak/master

Allow setting custom IP check URLs

.gitignore

@@ -2,3 +2,6 @@ config.json
 digitalocean-dynamic-ip
 digitalocean-dynamic-dns-ip
 digitalocean-dynamic-ip.json
+
+# GoLand IDE
+.idea/

README.md

@@ -1,7 +1,7 @@
 # DIGITAL OCEAN DYNAMIC IP API CLIENT
 A simple script in Go language to automatically update Digital ocean DNS records if you have a dynamic IP. Since it can be compiled on any platform, you can use it along with raspberrypi etc.
 
-To find your Dynamic IP, this program will call out to https://ipv4bot.whatismyipaddress.com for ipv4 addresses and https://ipv6bot.whatismyipaddress.com for ipv6 addresses. This is to support dual-stack environments.
+To find your Dynamic IP, this program will call out to https://ipv4bot.whatismyipaddress.com for ipv4 addresses and https://ipv6bot.whatismyipaddress.com for ipv6 addresses. This is to support dual-stack environments. (These URLs can be customized; see Usage, below.)
 
 ## Requirements
 Requires Git, Go 1.8+, and https://github.com/mitchellh/go-homedir for building.
@@ -18,17 +18,20 @@ Once the module is fetched, you should be able to compile the program using `go
 
 ## Usage
 ```bash
+# clone the repo in ~/go/src/github.com/anaganisk:
 git clone https://github.com/anaganisk/digitalocean-dynamic-dns-ip.git
 ```
-create a file ".digitalocean-dynamic-ip.json"(dot prefix to hide the file) and place it user home directory and add the following json
+
+Create a file `.digitalocean-dynamic-ip.json` (dot prefix to hide the file) and place it in your home directory. Add the following JSON (or refer to the sample configuration file, `digitalocean-dynamic-ip.sample.json`):
 
 ```json
 {
   "apikey": "samplekeydasjkdhaskjdhrwofihsamplekey",
-  "doPageSize" : 20,
+  "doPageSize": 20,
   "useIPv4": true,
   "useIPv6": false,
   "allowIPv4InIPv6": false,
+  "ipv4CheckUrl": "https://ipv4bot.whatismyipaddress.com",
   "domains": [
     {
       "domain": "example.com",
@@ -52,6 +55,7 @@ create a file ".digitalocean-dynamic-ip.json"(dot prefix to hide the file) and p
   ]
 }
 ```
+
 The TTL can optionally be updated if passed in the configuration. Digital Ocean has a minimum TTL of 30 seconds. The `type` and the `name` must match existing records in the Digital Ocean DNS configuration. Only `types` of `A` and `AAAA` allowed at the moment.
 
 If you want to reduce the number of calls made to the digital ocean API and have more than 20 DNS records in your domain, you can adjust the `doPageSize` parameter. By default, Digital Ocean returns 20 records per page. Digital Ocean has a max page size of 200 items.
@@ -60,22 +64,25 @@ By default, the configuration checks both IPv4 and IPv6 addresses assuming your
 
 The `allowIPv4InIPv6` configuration option will allow adding an IPv4 address to be used in a AAAA record for IPv6 lookups.
 
+The `ipv4CheckUrl` and `ipv6CheckUrl` configuration settings are optional. If set, they must be URLs which respond to a GET request, with a plaintext response containing only your IP address. If unset, they default to `https://ipv_bot.whatismyipaddress.com`.
+
 ```bash
-#run
-go build digitalocean-dynamic-ip.go
+# after running `go build digitalocean-dynamic-ip.go`, run:
 ./digitalocean-dynamic-ip
 ```
 
 Optionally, you can create the configuration file with any name wherever you want, and pass it as a command line argument:
+
 ```bash
-#run
+#run:
 ./digitalocean-dynamic-ip /path/to/my/config.json
 ```
 
 You can either set this to run periodically with a cronjob or use your own method.
+
 ```bash
-# run crontab -e
-# sample cron job task 
+# run `crontab -e` to edit your crontab
+# sample cron job task
 
 # m h  dom mon dow   command
 */5 * * * * /home/user/digitalocean-dynamic-dns-ip/digitalocean-dynamic-ip

digitalocean-dynamic-ip.go

@@ -31,6 +31,8 @@ type ClientConfig struct {
 	DOPageSize      int      `json:"doPageSize"`
 	UseIPv4         *bool    `json:"useIPv4"`
 	UseIPv6         *bool    `json:"useIPv6"`
+	IPv4CheckURL    string   `json:"ipv4CheckUrl"`
+	IPv6CheckURL    string   `json:"ipv6CheckUrl"`
 	AllowIPv4InIPv6 bool     `json:"allowIPv4InIPv6"`
 	Domains         []Domain `json:"domains"`
 }
@@ -118,9 +120,17 @@ func usage() {
 //CheckLocalIPs : get current IP of server. checks both IPv4 and Ipv6 to support dual stack environments
 func CheckLocalIPs() (ipv4, ipv6 net.IP) {
 	var ipv4String, ipv6String string
+	ipv4CheckUrl := "https://ipv4bot.whatismyipaddress.com"
+	ipv6CheckUrl := "https://ipv6bot.whatismyipaddress.com"
+	if len(config.IPv4CheckURL) > 0 {
+		ipv4CheckUrl = config.IPv4CheckURL
+	}
+	if len(config.IPv6CheckURL) > 0 {
+		ipv6CheckUrl = config.IPv6CheckURL
+	}
 
 	if config.UseIPv4 == nil || *(config.UseIPv4) {
-		ipv4String, _ = getURLBody("https://ipv4bot.whatismyipaddress.com")
+		ipv4String, _ = getURLBody(ipv4CheckUrl)
 		if ipv4String == "" {
 			log.Println("No IPv4 address found. Consider disabling IPv4 checks in the config `\"useIPv4\": false`")
 		} else {
@@ -128,6 +138,7 @@ func CheckLocalIPs() (ipv4, ipv6 net.IP) {
 			if ipv4 != nil {
 				// make sure we got back an actual ipv4 address
 				ipv4 = ipv4.To4()
+				log.Printf("Discovered IPv4 address `%s`", ipv4.String())
 			}
 			if ipv4 == nil {
 				log.Printf("Unable to parse `%s` as an IPv4 address", ipv4String)
@@ -136,13 +147,15 @@ func CheckLocalIPs() (ipv4, ipv6 net.IP) {
 	}
 
 	if config.UseIPv6 == nil || *(config.UseIPv6) {
-		ipv6String, _ = getURLBody("https://ipv6bot.whatismyipaddress.com")
+		ipv6String, _ = getURLBody(ipv6CheckUrl)
 		if ipv6String == "" {
 			log.Println("No IPv6 address found. Consider disabling IPv6 checks in the config `\"useIPv6\": false`")
 		} else {
 			ipv6 = net.ParseIP(ipv6String)
 			if ipv6 == nil {
 				log.Printf("Unable to parse `%s` as an IPv6 address", ipv6String)
+			} else {
+				log.Printf("Discovered IPv6 address `%s`", ipv6.String())
 			}
 		}
 	}
@@ -151,9 +164,7 @@ func CheckLocalIPs() (ipv4, ipv6 net.IP) {
 
 func getURLBody(url string) (string, error) {
 	request, err := http.Get(url)
-	if err != nil {
-		return "", err
-	}
+	checkError(err)
 	defer request.Body.Close()
 	body, err := ioutil.ReadAll(request.Body)
 	checkError(err)
@@ -206,10 +217,10 @@ func UpdateRecords(domain Domain, ipv4, ipv6 net.IP) {
 	doRecords := GetDomainRecords(domain.Domain)
 	// look for the item to update
 	if len(doRecords) < 1 {
-		log.Printf("%s: No DNS records found in Digital Ocean", domain.Domain)
+		log.Printf("%s: No DNS records found in DigitalOcean", domain.Domain)
 		return
 	}
-	log.Printf("%s: %d DNS records found in Digital Ocean", domain.Domain, len(doRecords))
+	log.Printf("%s: %d DNS records found in DigitalOcean", domain.Domain, len(doRecords))
 	for _, toUpdateRecord := range domain.Records {
 		if toUpdateRecord.Type != "A" && toUpdateRecord.Type != "AAAA" {
 			log.Printf("%s: Unsupported type (Only A and AAAA records supported) for updates %+v", domain.Domain, toUpdateRecord)
@@ -327,7 +338,7 @@ func main() {
 	config = GetConfig()
 	currentIPv4, currentIPv6 := CheckLocalIPs()
 	if currentIPv4 == nil && currentIPv6 == nil {
-		log.Fatal("current IP addresses are not a valid, or both are disabled in the config. Check you configuration and internet connection")
+		log.Fatal("Current IP addresses are not valid, or both are disabled in the config. Check your configuration and internet connection.")
 	}
 	for _, domain := range config.Domains {
 		log.Printf("%s: START", domain.Domain)

digitalocean-dynamic-ip.sample.json

@@ -3,6 +3,8 @@
   "doPageSize": 20,
   "useIPv4": true,
   "useIPv6": true,
+  "ipv4CheckUrl": "https://ipv4bot.whatismyipaddress.com",
+  "ipv6CheckUrl": "https://ipv6bot.whatismyipaddress.com",
   "allowIPv4InIPv6": false,
   "domains": [
     {
@@ -11,6 +13,10 @@
         {
           "name": "subdomainOrRecord",
           "type": "A"
+        },
+        {
+          "name": "subdomainOrRecord",
+          "type": "AAAA"
         }
       ]
     },