feat: add "env://" scheme for blob load

Signed-off-by: Zachary Newman <z@znewman.net>
sigstore · Apr 24, 2022 · 25a008e · 25a008e
1 parent 89dd9a9
commit 25a008e
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Showing 2 changed files with 30 additions and 1 deletion.
diff --git a/pkg/blob/load.go b/pkg/blob/load.go
@@ -43,6 +43,13 @@ func LoadFileOrURL(fileRef string) ([]byte, error) {
 			if err != nil {
 				return nil, err
 			}
+		case "env://":
+			envVar := parts[1]
+			value, found := os.LookupEnv(envVar)
+			if !found {
+				return nil, fmt.Errorf("loading URL: env var $%s not found", envVar)
+			}
+			raw = []byte(value)
 		default:
 			return nil, fmt.Errorf("loading URL: unrecognized scheme: %s", scheme)
 		}

diff --git a/pkg/blob/load_test.go b/pkg/blob/load_test.go
@@ -62,8 +62,30 @@ func TestLoadFileOrURL(t *testing.T) {
 		t.Errorf("LoadFileOrURL(HTTP) = '%s'; want '%s'", actual, data)
 	}
 
+	os.Setenv("MY_ENV_VAR", string(data))
+	actual, err = LoadFileOrURL("env://MY_ENV_VAR")
+	if err != nil {
+		t.Errorf("Reading from environment failed: %v", err)
+	} else if !bytes.Equal(actual, data) {
+		t.Errorf("LoadFileOrURL(env) = '%s'; want '%s'", actual, data)
+	}
+
+	os.Setenv("MY_ENV_VAR", "")
+	actual, err = LoadFileOrURL("env://MY_ENV_VAR")
+	if err != nil {
+		t.Errorf("Reading from environment failed: %v", err)
+	} else if !bytes.Equal(actual, make([]byte, 0)) {
+		t.Errorf("LoadFileOrURL(env) = '%s'; should be empty", actual)
+	}
+
+	os.Unsetenv("MY_ENV_VAR")
+	_, err = LoadFileOrURL("env://MY_ENV_VAR")
+	if err == nil {
+		t.Error("LoadFileOrURL(): expected error for unset env var")
+	}
+
 	_, err = LoadFileOrURL("invalid://url")
 	if err == nil {
-		t.Error("LoadFileOrURL(): expected error")
+		t.Error("LoadFileOrURL(): expected error for invalid scheme")
 	}
 }