Allow using any default branch name for template repos

**What**
- Use the git server's default remote branch when the template repo
  refName is empty. This allows us to support _any_ default branch
  instead of the previously hard coded `master`

Signed-off-by: Lucas Roesler <roesler.lucas@gmail.com>

commands/fetch_templates.go

@@ -35,8 +35,15 @@ func fetchTemplates(templateURL string, refName string, overwrite bool) error {
 
 	log.Printf("Attempting to expand templates from %s\n", templateURL)
 	pullDebugPrint(fmt.Sprintf("Temp files in %s", dir))
-	args := map[string]string{"dir": dir, "repo": templateURL, "refname": refName}
-	if err := versioncontrol.GitClone.Invoke(".", args); err != nil {
+	args := map[string]string{"dir": dir, "repo": templateURL}
+	cmd := versioncontrol.GitCloneDefault
+
+	if refName != "" {
+		args["refname"] = refName
+		cmd = versioncontrol.GitClone
+	}
+
+	if err := cmd.Invoke(".", args); err != nil {
 		return err
 	}
 
@@ -126,11 +133,14 @@ func pullTemplate(repository string) error {
 
 	repository, refName := versioncontrol.ParsePinnedRemote(repository)
 
-	if err := versioncontrol.GitCheckRefName.Invoke("", map[string]string{"refname": refName}); err != nil {
-		fmt.Printf("Invalid tag or branch name `%s`\n", refName)
-		fmt.Println("See https://git-scm.com/docs/git-check-ref-format for more details of the rules Git enforces on branch and reference names.")
+	if refName != "" {
+		err := versioncontrol.GitCheckRefName.Invoke("", map[string]string{"refname": refName})
+		if err != nil {
+			fmt.Printf("Invalid tag or branch name `%s`\n", refName)
+			fmt.Println("See https://git-scm.com/docs/git-check-ref-format for more details of the rules Git enforces on branch and reference names.")
 
-		return err
+			return err
+		}
 	}
 
 	fmt.Printf("Fetch templates from repository: %s at %s\n", repository, refName)

commands/fetch_templates_test.go

@@ -33,6 +33,16 @@ func Test_PullTemplates(t *testing.T) {
 		}
 
 	})
+
+	t.Run("fetchTemplates with default ref", func(t *testing.T) {
+		defer tearDownFetchTemplates(t)
+
+		err := fetchTemplates(localTemplateRepository, "", false)
+		if err != nil {
+			t.Error(err)
+		}
+
+	})
 }
 
 // setupLocalTemplateRepo will create a local copy of the core OpenFaaS templates, this

versioncontrol/git.go

@@ -14,7 +14,15 @@ var GitClone = &vcsCmd{
 	scheme: []string{"git", "https", "http", "git+ssh", "ssh"},
 }
 
-// GitCheckout defines the command to clone a repo into a directory
+// GitClone defines the command to clone the default branch of a repo into a directory
+var GitCloneDefault = &vcsCmd{
+	name:   "Git",
+	cmd:    "git",
+	cmds:   []string{"clone {repo} {dir} --depth=1 --config core.autocrlf=false"},
+	scheme: []string{"git", "https", "http", "git+ssh", "ssh"},
+}
+
+// GitCheckout defines the command to clone a specific REF of repo into a directory
 var GitCheckout = &vcsCmd{
 	name:   "Git",
 	cmd:    "git",

versioncontrol/parse.go

@@ -35,7 +35,10 @@ func IsPinnedGitRemote(repoURL string) bool {
 
 // ParsePinnedRemote returns the remote url and contraint value from repository url
 func ParsePinnedRemote(repoURL string) (remoteURL, refName string) {
-	refName = "master"
+	// default refName is empty
+	// the template fetcher can detect this and will pull the default when
+	// the ref is empty
+	refName = ""
 	remoteURL = repoURL
 
 	// If using a Regexp in multiple goroutines,
@@ -54,7 +57,7 @@ func ParsePinnedRemote(repoURL string) (remoteURL, refName string) {
 	}
 
 	if !IsGitRemote(remoteURL) {
-		return repoURL, "master"
+		return remoteURL, refName
 	}
 
 	return remoteURL, refName

versioncontrol/parse_test.go

@@ -144,14 +144,14 @@ func Test_ParsePinnedRemote(t *testing.T) {
 
 		})
 
-		t.Run(fmt.Sprintf("can parse default refname from url with %s", scenario.name), func(t *testing.T) {
+		t.Run(fmt.Sprintf("can parse default empty refname from url with %s", scenario.name), func(t *testing.T) {
 			remote, refName := ParsePinnedRemote(scenario.url)
 			if remote != scenario.url {
 				t.Errorf("expected remote url: %s, got: %s", scenario.url, remote)
 			}
 
-			if refName != "master" {
-				t.Errorf("expected refName: master, got: %s", refName)
+			if refName != "" {
+				t.Errorf("expected emtpy refName, got: %s", refName)
 			}
 
 		})