From a8d74070936d4cddd144284faf669e9053630b9e Mon Sep 17 00:00:00 2001
From: Ian Fijolek <ian@iamthefij.com>
Date: Tue, 1 Dec 2020 20:27:27 -0800
Subject: [PATCH] Parse registry urls from image names

---
 main.go | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/main.go b/main.go
index 9ac0b00..b07b88e 100644
--- a/main.go
+++ b/main.go
@@ -17,8 +17,8 @@ import (
 )
 
 var (
-	// registryBaseURL is the base URL of the docker registry
-	registryBaseURL = "https://registry.hub.docker.com"
+	// defaultRegistryBaseURL is the base URL of the docker registry
+	defaultRegistryBaseURL = "https://hub.docker.com"
 	// maxPages is the max number of pages to fetch from docker registry results
 	maxPages = 10
 
@@ -31,6 +31,7 @@ var (
 // ImageTag is wraps an image and tag values for a container
 type ImageTag struct {
 	ImageTag     string
+	Registry     string
 	Image        string
 	TagDesc      string
 	Version      string
@@ -75,8 +76,14 @@ func ParseImageTag(imageTag string) (ImageTag, error) {
 
 	// Extract image name with repo
 	image := results[1]
-	if !strings.Contains(image, "/") {
+	registry := ""
+	switch strings.Count(image, "/") {
+	case 0:
 		image = "library/" + image
+	case 2:
+		parts := strings.Split(image, "/")
+		registry = parts[0]
+		image = strings.Join(parts[1:], "/")
 	}
 
 	// Extract version number
@@ -95,6 +102,7 @@ func ParseImageTag(imageTag string) (ImageTag, error) {
 	return ImageTag{
 		ImageTag:     imageTag,
 		Image:        image,
+		Registry:     registry,
 		Version:      version,
 		VersionParts: versionParts,
 		TagDesc:      results[4],
@@ -132,6 +140,10 @@ func listTags(current ImageTag) ([]ImageTag, error) {
 		}
 	}
 
+	registryBaseURL := defaultRegistryBaseURL
+	if current.Registry != "" {
+		registryBaseURL = fmt.Sprintf("https://%s", current.Registry)
+	}
 	url := fmt.Sprintf("%s/v2/repositories/%s/tags", registryBaseURL, current.Image)
 	pageCount := 0
 	var response tagsResponse