feat(publicip/http): add Spdyn provider

README.md

@@ -259,6 +259,7 @@ You can otherwise customize it with the following:
   - `ifconfig` using [https://ifconfig.io/ip](https://ifconfig.io/ip)
   - `ipinfo` using [https://ipinfo.io/ip](https://ipinfo.io/ip)
   - `google` using [https://domains.google.com/checkip](https://domains.google.com/checkip)
+  - `spdyn` using [https://checkip.spdyn.de](https://checkip.spdyn.de/)
   - You can also specify an HTTPS URL such as `https://ipinfo.io/ip`
 - `PUBLICIPV4_HTTP_PROVIDERS` gets your public IPv4 address only. It can be one or more of the following:
   - `ipify` using [https://api.ipify.org](https://api.ipify.org)

pkg/publicip/http/providers.go

@@ -16,6 +16,7 @@ const (
 	Ifconfig Provider = "ifconfig"
 	Ipify    Provider = "ipify"
 	Ipinfo   Provider = "ipinfo"
+	Spdyn    Provider = "spdyn"
 )
 
 func ListProviders() []Provider {
@@ -24,6 +25,7 @@ func ListProviders() []Provider {
 		Ifconfig,
 		Ipify,
 		Ipinfo,
+		Spdyn,
 	}
 }
 
@@ -82,6 +84,8 @@ func (provider Provider) url(version ipversion.IPVersion) (url string, ok bool)
 			url = "https://ifconfig.io/ip"
 		case Ipinfo:
 			url = "https://ipinfo.io/ip"
+		case Spdyn:
+			url = "https://checkip.spdyn.de"
 		}
 	}
 

pkg/publicip/http/providers_test.go

@@ -19,7 +19,7 @@ func Test_ListProvidersForVersion(t *testing.T) {
 	}{
 		"ip4or6": {
 			version:   ipversion.IP4or6,
-			providers: []Provider{Google, Ifconfig, Ipify, Ipinfo},
+			providers: []Provider{Google, Ifconfig, Ipify, Ipinfo, Spdyn},
 		},
 		"ip4": {
 			version:   ipversion.IP4,