command/token: HelperPath

command/token/helper.go

@@ -4,8 +4,29 @@ import (
 	"bytes"
 	"fmt"
 	"os/exec"
+	"path/filepath"
+	"strings"
 )
 
+// HelperPath takes the configured path to a helper and expands it to
+// a full absolute path that can be executed. If the path is relative then
+// a prefix of "vault token-" will be prepended to the path.
+func HelperPath(path string) string {
+	space := strings.Index(path, " ")
+	if space == -1 {
+		space = len(path)
+	}
+
+	// Get the binary name. If it isn't absolute, prepend "vault token-"
+	binary := path[0:space]
+	if !filepath.IsAbs(binary) {
+		binary = "vault token-" + binary
+	}
+
+	// Return the resulting string
+	return fmt.Sprintf("%s%s", binary, path[space:])
+}
+
 // Helper is the struct that has all the logic for storing and retrieving
 // tokens from the token helper. The API for the helpers is simple: the
 // Path is executed within a shell. The last argument appended will be the

command/token/helper_test.go

@@ -9,6 +9,22 @@ import (
 	"testing"
 )
 
+func TestHelperPath(t *testing.T) {
+	cases := map[string]string{
+		"/foo": "/foo",
+		"foo":  "vault token-foo",
+	}
+
+	for k, v := range cases {
+		actual := HelperPath(k)
+		if actual != v {
+			t.Fatalf(
+				"input: %s, expected: %s, got: %s",
+				k, v, actual)
+		}
+	}
+}
+
 func TestHelper(t *testing.T) {
 	h := testHelper(t)
 	Test(t, h.Path)