Merge pull request #6 from zozs/master

feat: add optional IPv6 support for Docker Hub

README.md

@@ -93,6 +93,7 @@ make docker
 | DOCKERHUB_REPO_IMAGE |         ratelimitpreview/test         |        custom repository/image        |
 | ENABLE_FILE_AUTH |         false         |        Load auth credentials from docker config file<br>at /$FILE_AUTH_DIR/config.json<br>Must leave auth through ENV empty.       |
 | FILE_AUTH_DIR |         /config         |        Directory where config.json resides       |
+| ENABLE_IPV6   |         false           | Use IPv6 instead of IPv4 when fetching rate limits |
 <br>
 
 Example docker configuration config.json file below. <br>

internal/collector/collector.go

@@ -29,9 +29,17 @@ var DockerLabels = make(map[string]string, 1)
 // GetMetrics will save metrics in a float64 map
 func GetMetrics() {
 	l := log.New(os.Stdout, "drl-exporter ", log.LstdFlags)
-	tokenUrl := "https://auth.docker.io/token?service=" +
+
+	tokenBaseUrl := "https://auth.docker.io"
+	repoBaseUrl := "https://registry-1.docker.io"
+	if *vars.EnableIPv6 {
+		tokenBaseUrl = "https://auth.ipv6.docker.com"
+		repoBaseUrl = "https://registry.ipv6.docker.com"
+	}
+
+	tokenUrl := tokenBaseUrl + "/token?service=" +
 		"registry.docker.io&scope=repository:" + *vars.DockerRepoImage + ":pull"
-	repoUrl := "https://registry-1.docker.io/v2/" +
+	repoUrl := repoBaseUrl + "/v2/" +
 		"registry.docker.io&scope=repository:" + *vars.DockerRepoImage + "/manifests/latest"
 
 	tr, err := tokenRequest(tokenUrl)

internal/vars/envars.go

@@ -12,4 +12,5 @@ var (
 	EnableUserAuth  = env.Bool("ENABLE_USER_AUTH", false, false, "Enable metrics for users")
 	EnableFileAuth  = env.Bool("ENABLE_FILE_AUTH", false, false, "Enable authentication through docker configuration file 'config.json'")
 	FileAuthDir     = env.String("FILE_AUTH_DIR", false, "/config", "Directory to load 'config.json' docker configuration from")
+	EnableIPv6      = env.Bool("ENABLE_IPV6", false, false, "Use IPv6 instead of IPv4")
 )