Use indentation of 2 when rewriting auto-migrated config file

This seems to be what most people use when indenting yaml files, and it seems to
make more sense than the default of 4.

We also use it the example config in Config.md.

pkg/utils/yaml_utils/yaml_utils.go

@@ -1,6 +1,7 @@
 package yaml_utils
 
 import (
+	"bytes"
 	"errors"
 	"fmt"
 
@@ -34,7 +35,7 @@ func UpdateYamlValue(yamlBytes []byte, path []string, value string) ([]byte, err
 	}
 
 	// Convert the updated YAML node back to YAML bytes.
-	updatedYAMLBytes, err := yaml.Marshal(body)
+	updatedYAMLBytes, err := yamlMarshal(body)
 	if err != nil {
 		return nil, fmt.Errorf("failed to convert YAML node to bytes: %w", err)
 	}
@@ -126,7 +127,7 @@ func TransformNode(yamlBytes []byte, path []string, transform func(node *yaml.No
 	}
 
 	// Convert the updated YAML node back to YAML bytes.
-	updatedYAMLBytes, err := yaml.Marshal(body)
+	updatedYAMLBytes, err := yamlMarshal(body)
 	if err != nil {
 		return nil, fmt.Errorf("failed to convert YAML node to bytes: %w", err)
 	}
@@ -170,7 +171,7 @@ func RenameYamlKey(yamlBytes []byte, path []string, newKey string) ([]byte, erro
 	}
 
 	// Convert the updated YAML node back to YAML bytes.
-	updatedYAMLBytes, err := yaml.Marshal(body)
+	updatedYAMLBytes, err := yamlMarshal(body)
 	if err != nil {
 		return nil, fmt.Errorf("failed to convert YAML node to bytes: %w", err)
 	}
@@ -227,7 +228,7 @@ func Walk(yamlBytes []byte, callback func(node *yaml.Node, path string) bool) ([
 	}
 
 	// Convert the updated YAML node back to YAML bytes.
-	updatedYAMLBytes, err := yaml.Marshal(body)
+	updatedYAMLBytes, err := yamlMarshal(body)
 	if err != nil {
 		return nil, fmt.Errorf("failed to convert YAML node to bytes: %w", err)
 	}
@@ -273,3 +274,12 @@ func walk(node *yaml.Node, path string, callback func(*yaml.Node, string) bool)
 
 	return didChange, nil
 }
+
+func yamlMarshal(node *yaml.Node) ([]byte, error) {
+	var buffer bytes.Buffer
+	encoder := yaml.NewEncoder(&buffer)
+	encoder.SetIndent(2)
+
+	err := encoder.Encode(node)
+	return buffer.Bytes(), err
+}

pkg/utils/yaml_utils/yaml_utils_test.go

@@ -50,12 +50,11 @@ func TestUpdateYamlValue(t *testing.T) {
 			expectedErr: "",
 		},
 		{
-			name:  "nested update",
+			name:        "nested update",
-			in:    "foo:\n  bar: baz\n",
+			in:          "foo:\n  bar: baz\n",
-			path:  []string{"foo", "bar"},
+			path:        []string{"foo", "bar"},
-			value: "qux",
+			value:       "qux",
-			// indentation is not preserved. See https://github.com/go-yaml/yaml/issues/899
+			expectedOut: "foo:\n  bar: qux\n",
-			expectedOut: "foo:\n    bar: qux\n",
 			expectedErr: "",
 		},
 		{
@@ -63,7 +62,7 @@ func TestUpdateYamlValue(t *testing.T) {
 			in:          "",
 			path:        []string{"foo", "bar", "baz"},
 			value:       "qux",
-			expectedOut: "foo:\n    bar:\n        baz: qux\n",
+			expectedOut: "foo:\n  bar:\n    baz: qux\n",
 			expectedErr: "",
 		},
 		{
@@ -134,21 +133,19 @@ func TestRenameYamlKey(t *testing.T) {
 			expectedErr: "",
 		},
 		{
-			name:   "rename key, nested",
+			name:        "rename key, nested",
-			in:     "foo:\n  bar: 5\n",
+			in:          "foo:\n  bar: 5\n",
-			path:   []string{"foo", "bar"},
+			path:        []string{"foo", "bar"},
-			newKey: "baz",
+			newKey:      "baz",
-			// indentation is not preserved. See https://github.com/go-yaml/yaml/issues/899
+			expectedOut: "foo:\n  baz: 5\n",
-			expectedOut: "foo:\n    baz: 5\n",
 			expectedErr: "",
 		},
 		{
-			name:   "rename non-scalar key",
+			name:        "rename non-scalar key",
-			in:     "foo:\n  bar: 5\n",
+			in:          "foo:\n  bar: 5\n",
-			path:   []string{"foo"},
+			path:        []string{"foo"},
-			newKey: "qux",
+			newKey:      "qux",
-			// indentation is not preserved. See https://github.com/go-yaml/yaml/issues/899
+			expectedOut: "qux:\n  bar: 5\n",
-			expectedOut: "qux:\n    bar: 5\n",
 			expectedErr: "",
 		},
 		{
@@ -288,8 +285,7 @@ func TestWalk_inPlaceChanges(t *testing.T) {
 				}
 				return false
 			},
-			// indentation is not preserved. See https://github.com/go-yaml/yaml/issues/899
+			expectedOut: "x:\n  y: 7\n",
-			expectedOut: "x:\n    y: 7\n",
 		},
 		{
 			name: "change array value",
@@ -301,8 +297,7 @@ func TestWalk_inPlaceChanges(t *testing.T) {
 				}
 				return false
 			},
-			// indentation is not preserved. See https://github.com/go-yaml/yaml/issues/899
+			expectedOut: "x:\n  - y: 7\n",
-			expectedOut: "x:\n    - y: 7\n",
 		},
 	}
 
@@ -366,8 +361,8 @@ foo:
 			path:      []string{"foo", "bar"},
 			transform: transformIntValueToString,
 			expectedOut: `foo:
-    bar: "2"
+  bar: "2"
-`, // Note the indentiation change and newlines because of how it re-marshalls
+`, // Note the trailing newline changes because of how it re-marshalls
 		},
 		{
 			name: "Does nothing when already transformed",