Fix DockerfileService to properly parse repo names and tags

Before this change, the tag name would be included in the image, which breaks the API

static/js/services/dockerfile-service.js

@@ -12,20 +12,46 @@ angular.module('quay').factory('DockerfileService', ['DataFileService', 'Config'
   DockerfileInfo.prototype.getRegistryBaseImage = function() {
     var baseImage = this.getBaseImage();
     if (!baseImage) {
-      return;
+      return null;
     }
 
     if (baseImage.indexOf(Config.getDomain() + '/') != 0) {
-      return;
+      return null;
     }
 
     return baseImage.substring(Config.getDomain().length + 1);
   };
 
   DockerfileInfo.prototype.getBaseImage = function() {
+    var imageAndTag = this.getBaseImageAndTag();
+    if (!imageAndTag) {
+      return null;
+    }
+
+    // Note, we have to handle a few different cases here:
+    // 1) someimage
+    // 2) someimage:tag
+    // 3) host:port/someimage
+    // 4) host:port/someimage:tag
+    var lastIndex = imageAndTag.lastIndexOf(':');
+    if (lastIndex < 0) {
+      return imageAndTag;
+    }
+
+    // Otherwise, check if there is a / in the portion after the split point. If so,
+    // then the latter is part of the path (and not a tag).
+    var afterColon = imageAndTag.substring(lastIndex + 1);
+    if (afterColon.indexOf('/') >= 0) {
+      return imageAndTag;
+    }
+
+    return imageAndTag.substring(0, lastIndex);
+  };
+
+  DockerfileInfo.prototype.getBaseImageAndTag = function() {
     var fromIndex = this.contents.indexOf('FROM ');
     if (fromIndex < 0) {
-      return;
+      return null;
     }
 
     var newline = this.contents.indexOf('\n', fromIndex);