config/module: detect GitHub URLs

config/module/detect.go

@@ -20,6 +20,7 @@ var Detectors []Detector
 
 func init() {
 	Detectors = []Detector{
+		new(GitHubDetector),
 		new(FileDetector),
 	}
 }

config/module/detect_github.go

@@ -0,0 +1,63 @@
+package module
+
+import (
+	"fmt"
+	"net/url"
+	"strings"
+)
+
+// GitHubDetector implements Detector to detect GitHub URLs and turn
+// them into URLs that the Git Getter can understand.
+type GitHubDetector struct{}
+
+func (d *GitHubDetector) Detect(src, _ string) (string, bool, error) {
+	if len(src) == 0 {
+		return "", false, nil
+	}
+
+	if strings.HasPrefix(src, "github.com/") {
+		return d.detectHTTP(src)
+	} else if strings.HasPrefix(src, "git@github.com:") {
+		return d.detectSSH(src)
+	}
+
+	return "", false, nil
+}
+
+func (d *GitHubDetector) detectHTTP(src string) (string, bool, error) {
+	urlStr := fmt.Sprintf("https://%s", src)
+	url, err := url.Parse(urlStr)
+	if err != nil {
+		return "", true, fmt.Errorf("error parsing GitHub URL: %s", err)
+	}
+
+	if !strings.HasSuffix(url.Path, ".git") {
+		url.Path += ".git"
+	}
+
+	return "git::" + url.String(), true, nil
+}
+
+func (d *GitHubDetector) detectSSH(src string) (string, bool, error) {
+	idx := strings.Index(src, ":")
+	qidx := strings.Index(src, "?")
+	if qidx == -1 {
+		qidx = len(src)
+	}
+
+	var u url.URL
+	u.Scheme = "ssh"
+	u.User = url.User("git")
+	u.Host = "github.com"
+	u.Path = src[idx+1:qidx]
+	if qidx < len(src) {
+		q, err := url.ParseQuery(src[qidx+1:])
+		if err != nil {
+			return "", true, fmt.Errorf("error parsing GitHub SSH URL: %s", err)
+		}
+
+		u.RawQuery = q.Encode()
+	}
+
+	return "git::"+u.String(), true, nil
+}

config/module/detect_github_test.go

@@ -0,0 +1,47 @@
+package module
+
+import (
+	"testing"
+)
+
+func TestGitHubDetector(t *testing.T) {
+	cases := []struct {
+		Input  string
+		Output string
+	}{
+		// HTTP
+		{"github.com/hashicorp/foo", "git::https://github.com/hashicorp/foo.git"},
+		{"github.com/hashicorp/foo.git", "git::https://github.com/hashicorp/foo.git"},
+		{
+			"github.com/hashicorp/foo?foo=bar",
+			"git::https://github.com/hashicorp/foo.git?foo=bar",
+		},
+		{
+			"github.com/hashicorp/foo.git?foo=bar",
+			"git::https://github.com/hashicorp/foo.git?foo=bar",
+		},
+
+		// SSH
+		{"git@github.com:hashicorp/foo.git", "git::ssh://git@github.com/hashicorp/foo.git"},
+		{
+			"git@github.com:hashicorp/foo.git?foo=bar",
+			"git::ssh://git@github.com/hashicorp/foo.git?foo=bar",
+		},
+	}
+
+	pwd := "/pwd"
+	f := new(GitHubDetector)
+	for i, tc := range cases {
+		output, ok, err := f.Detect(tc.Input, pwd)
+		if err != nil {
+			t.Fatalf("err: %s", err)
+		}
+		if !ok {
+			t.Fatal("not ok")
+		}
+
+		if output != tc.Output {
+			t.Fatalf("%d: bad: %#v", i, output)
+		}
+	}
+}