switch to gopkg.in/yaml.v3

cli/command/stack/config.go

@@ -1,6 +1,7 @@
 package stack
 
 import (
+	"bytes"
 	"fmt"
 
 	"github.com/docker/cli/cli"
@@ -11,7 +12,7 @@ import (
 	composeLoader "github.com/docker/cli/cli/compose/loader"
 	composetypes "github.com/docker/cli/cli/compose/types"
 	"github.com/spf13/cobra"
-	yaml "gopkg.in/yaml.v2"
+	"gopkg.in/yaml.v3"
 )
 
 func newConfigCommand(dockerCli command.Cli) *cobra.Command {
@@ -54,9 +55,12 @@ func outputConfig(configFiles composetypes.ConfigDetails, skipInterpolation bool
 		return "", err
 	}
 
-	d, err := yaml.Marshal(&config)
+	var buf bytes.Buffer
+	enc := yaml.NewEncoder(&buf)
+	enc.SetIndent(2)
+	err = enc.Encode(&config)
 	if err != nil {
 		return "", err
 	}
-	return string(d), nil
+	return buf.String(), nil
 }

cli/command/stack/config_test.go

@@ -45,8 +45,8 @@ services:
 services:
   foo:
     command:
-    - cat
-    - file2.txt
+      - cat
+      - file2.txt
     image: busybox:1.0
 `,
 		},
@@ -69,8 +69,8 @@ services:
 services:
   foo:
     command:
-    - cat
-    - file2.txt
+      - cat
+      - file2.txt
     image: busybox:${VERSION}
 `,
 		},

cli/compose/loader/loader.go

@@ -25,7 +25,7 @@ import (
 	"github.com/google/shlex"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
-	yaml "gopkg.in/yaml.v2"
+	"gopkg.in/yaml.v3"
 )
 
 // Options supported by Load
@@ -53,11 +53,11 @@ func ParseYAML(source []byte) (map[string]any, error) {
 	if err := yaml.Unmarshal(source, &cfg); err != nil {
 		return nil, err
 	}
-	cfgMap, ok := cfg.(map[any]any)
+	_, ok := cfg.(map[string]any)
 	if !ok {
 		return nil, errors.Errorf("top-level object must be a mapping")
 	}
-	converted, err := convertToStringKeysRecursive(cfgMap, "")
+	converted, err := convertToStringKeysRecursive(cfg, "")
 	if err != nil {
 		return nil, err
 	}
@@ -349,24 +349,20 @@ func createTransformHook(additionalTransformers ...Transformer) mapstructure.Dec
 
 // keys needs to be converted to strings for jsonschema
 func convertToStringKeysRecursive(value any, keyPrefix string) (any, error) {
-	if mapping, ok := value.(map[any]any); ok {
+	if mapping, ok := value.(map[string]any); ok {
 		dict := make(map[string]any)
 		for key, entry := range mapping {
-			str, ok := key.(string)
-			if !ok {
-				return nil, formatInvalidKeyError(keyPrefix, key)
-			}
 			var newKeyPrefix string
 			if keyPrefix == "" {
-				newKeyPrefix = str
+				newKeyPrefix = key
 			} else {
-				newKeyPrefix = fmt.Sprintf("%s.%s", keyPrefix, str)
+				newKeyPrefix = fmt.Sprintf("%s.%s", keyPrefix, key)
 			}
 			convertedEntry, err := convertToStringKeysRecursive(entry, newKeyPrefix)
 			if err != nil {
 				return nil, err
 			}
-			dict[str] = convertedEntry
+			dict[key] = convertedEntry
 		}
 		return dict, nil
 	}
@@ -385,16 +381,6 @@ func convertToStringKeysRecursive(value any, keyPrefix string) (any, error) {
 	return value, nil
 }
 
-func formatInvalidKeyError(keyPrefix string, key any) error {
-	var location string
-	if keyPrefix == "" {
-		location = "at top level"
-	} else {
-		location = "in " + keyPrefix
-	}
-	return errors.Errorf("non-string key %s: %#v", location, key)
-}
-
 // LoadServices produces a ServiceConfig map from a compose file Dict
 // the servicesDict is not validated if directly used. Use Load() to enable validation
 func LoadServices(servicesDict map[string]any, workingDir string, lookupEnv template.Mapping) ([]types.ServiceConfig, error) {

cli/compose/loader/loader_test.go

@@ -332,6 +332,8 @@ func TestInvalidTopLevelObjectType(t *testing.T) {
 }
 
 func TestNonStringKeys(t *testing.T) {
+	// FIXME(thaJeztah): opkg.in/yaml.v3, which always unmarshals to a map[string]any, so we cannot produce a customized error for invalid types.
+	t.Skip("not supported by gopkg.in/yaml.v3, which always unmarshals to a map[string]any")
 	_, err := loadYAML(`
 version: "3"
 123: