configure upload URL when github_api_url is set

[#99533974]

Signed-off-by: Corbin Halliwill <challiwill@pivotal.io>

README.md

@@ -19,6 +19,10 @@ Fetches and creates versioned GitHub resources.
 * `github_api_url`: *Optional.* If you use a non-public GitHub deployment then
   you can set your API URL here.
 
+* `github_uploads_url`: *Optional.* Some GitHub instances have a separate URL
+  for uploading. If `github_api_url` is set, this value defaults to the same
+  value, but if you have your own endpoint, this field will override it.
+
 * `drafts`: *Optional. Default `false`.* When set to `true`, `put` produces
   drafts and `check` only detects drafts. If `false`, only non-draft releases
   will be detected and published. Note that releases must have semver compliant

github.go

@@ -55,6 +55,19 @@ func NewGitHubClient(source Source) (*GitHubClient, error) {
 		if err != nil {
 			return nil, err
 		}
+
+		client.UploadURL, err = url.Parse(source.GitHubAPIURL)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if source.GitHubUploadsURL != "" {
+		var err error
+		client.UploadURL, err = url.Parse(source.GitHubUploadsURL)
+		if err != nil {
+			return nil, err
+		}
 	}
 
 	return &GitHubClient{

resources.go

@@ -4,9 +4,10 @@ type Source struct {
 	User       string `json:"user"`
 	Repository string `json:"repository"`
 
-	GitHubAPIURL string `json:"github_api_url"`
-	AccessToken  string `json:"access_token"`
-	Drafts       bool   `json:"drafts"`
+	GitHubAPIURL     string `json:"github_api_url"`
+	GitHubUploadsURL string `json:"github_uploads_url"`
+	AccessToken      string `json:"access_token"`
+	Drafts           bool   `json:"drafts"`
 }
 
 type CheckRequest struct {