Add policy configuration

Author: emcfarlane

private/buf/bufmigrate/migrator.go

@@ -382,7 +382,8 @@ func (m *migrator) buildBufYAMLAndBufLockFiles(
 		bufYAML, err := bufconfig.NewBufYAMLFile(
 			bufconfig.FileVersionV2,
 			migrateBuilder.moduleConfigs,
-			// TODO: If we ever need to migrate from a v2 to v3, we will need to handle PluginConfigs
+			// TODO: If we ever need to migrate from a v2 to v3, we will need to handle PluginConfigs and PolicyConfigs
+			nil,
 			nil,
 			resolvedDeclaredRefs,
 		)
@@ -431,7 +432,8 @@ func (m *migrator) buildBufYAMLAndBufLockFiles(
 	bufYAML, err := bufconfig.NewBufYAMLFile(
 		bufconfig.FileVersionV2,
 		migrateBuilder.moduleConfigs,
-		// TODO: If we ever need to migrate from a v2 to v3, we will need to handle PluginConfigs
+		// TODO: If we ever need to migrate from a v2 to v3, we will need to handle PluginConfigs and PolicyConfigs
+		nil,
 		nil,
 		resolvedDepModuleRefs,
 	)

private/buf/cmd/buf/command/config/configinit/configinit.go

@@ -175,6 +175,7 @@ func run(
 		},
 		nil,
 		nil,
+		nil,
 		bufconfig.BufYAMLFileWithIncludeDocsLink(),
 	)
 	if err != nil {

private/buf/cmd/buf/command/config/configlsmodules/configlsmodules.go

@@ -143,6 +143,7 @@ func getExternalModules(
 				},
 				nil,
 				nil,
+				nil,
 			)
 			if err != nil {
 				return nil, err

private/buf/cmd/buf/command/config/internal/internal.go

@@ -178,6 +178,7 @@ func lsRun(
 			},
 			nil,
 			nil,
+			nil,
 		)
 		if err != nil {
 			return err

private/buf/cmd/buf/command/mod/internal/internal.go

@@ -164,6 +164,7 @@ func lsRun(
 			},
 			nil,
 			nil,
+			nil,
 		)
 		if err != nil {
 			return err

private/bufpkg/bufconfig/buf_policy_yaml_file.go

@@ -0,0 +1,285 @@
+// Copyright 2020-2025 Buf Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package bufconfig
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"slices"
+
+	"github.com/bufbuild/buf/private/pkg/encoding"
+	"github.com/bufbuild/buf/private/pkg/storage"
+	"github.com/bufbuild/buf/private/pkg/syserror"
+)
+
+const (
+	defaultBufPolicyYAMLFileName    = "buf.policy.yaml"
+	defaultBufPolicyYAMLFileVersion = FileVersionV2
+)
+
+var (
+	bufPolicyYAMLFileNames                       = []string{defaultBufPolicyYAMLFileName}
+	bufPolicyYAMLFileNameToSupportedFileVersions = map[string]map[FileVersion]struct{}{
+		defaultBufPolicyYAMLFileName: {
+			FileVersionV2: struct{}{},
+		},
+	}
+)
+
+// BufPolicyYAMLFile represents a buf.policy.yaml file.
+type BufPolicyYAMLFile interface {
+	File
+
+	// Name returns the name for the File.
+	Name() string
+	// LintConfig returns the LintConfig for the File.
+	LintConfig() LintConfig
+	// BreakingConfig returns the BreakingConfig for the File.
+	BreakingConfig() BreakingConfig
+	// PluginConfigs returns the PluginConfigs for the File.
+	PluginConfigs() []PluginConfig
+
+	isBufPolicyYAMLFile()
+}
+
+// NewBufPolicyYAMLFile returns a new validated BufPolicyYAMLFile.
+func NewBufPolicyYAMLFile(
+	fileVersion FileVersion,
+	name string,
+	lintConfig LintConfig,
+	breakingConfig BreakingConfig,
+	pluginConfigs []PluginConfig,
+) (BufPolicyYAMLFile, error) {
+	return newBufPolicyYAMLFile(
+		fileVersion,
+		nil,
+		name,
+		lintConfig,
+		breakingConfig,
+		pluginConfigs,
+	)
+}
+
+// GetBufPolicyYAMLFileForPrefix gets the buf.gen.yaml file at the given bucket prefix.
+//
+// The buf.gen.yaml file will be attempted to be read at prefix/buf.gen.yaml.
+func GetBufPolicyYAMLFileForPrefix(
+	ctx context.Context,
+	bucket storage.ReadBucket,
+	prefix string,
+) (BufPolicyYAMLFile, error) {
+	return getFileForPrefix(ctx, bucket, prefix, bufPolicyYAMLFileNames, bufPolicyYAMLFileNameToSupportedFileVersions, readBufPolicyYAMLFile)
+}
+
+// GetBufPolicyYAMLFileVersionForPrefix gets the buf.gen.yaml file version at the given bucket prefix.
+//
+// The buf.gen.yaml file will be attempted to be read at prefix/buf.gen.yaml.
+func GetBufPolicyYAMLFileVersionForPrefix(
+	ctx context.Context,
+	bucket storage.ReadBucket,
+	prefix string,
+) (FileVersion, error) {
+	return getFileVersionForPrefix(ctx, bucket, prefix, bufPolicyYAMLFileNames, bufPolicyYAMLFileNameToSupportedFileVersions, true, FileVersionV2, defaultBufPolicyYAMLFileVersion)
+}
+
+// PutBufPolicyYAMLFileForPrefix puts the buf.gen.yaml file at the given bucket prefix.
+//
+// The buf.gen.yaml file will be attempted to be written to prefix/buf.gen.yaml.
+// The buf.gen.yaml file will be written atomically.
+func PutBufPolicyYAMLFileForPrefix(
+	ctx context.Context,
+	bucket storage.WriteBucket,
+	prefix string,
+	bufYAMLFile BufPolicyYAMLFile,
+) error {
+	return putFileForPrefix(ctx, bucket, prefix, bufYAMLFile, defaultBufPolicyYAMLFileName, bufPolicyYAMLFileNameToSupportedFileVersions, writeBufPolicyYAMLFile)
+}
+
+// ReadBufPolicyYAMLFile reads the BufPolicyYAMLFile from the io.Reader.
+func ReadBufPolicyYAMLFile(reader io.Reader, fileName string) (BufPolicyYAMLFile, error) {
+	return readFile(reader, fileName, readBufPolicyYAMLFile)
+}
+
+// WriteBufPolicyYAMLFile writes the BufPolicyYAMLFile to the io.Writer.
+func WriteBufPolicyYAMLFile(writer io.Writer, bufPolicyYAMLFile BufPolicyYAMLFile) error {
+	return writeFile(writer, bufPolicyYAMLFile, writeBufPolicyYAMLFile)
+}
+
+// *** PRIVATE ***
+
+type bufPolicyYAMLFile struct {
+	fileVersion    FileVersion
+	objectData     ObjectData
+	name           string
+	lintConfig     LintConfig
+	breakingConfig BreakingConfig
+	pluginConfigs  []PluginConfig
+}
+
+func newBufPolicyYAMLFile(
+	fileVersion FileVersion,
+	objectData ObjectData,
+	name string,
+	lintConfig LintConfig,
+	breakingConfig BreakingConfig,
+	pluginConfigs []PluginConfig,
+) (*bufPolicyYAMLFile, error) {
+	return &bufPolicyYAMLFile{
+		fileVersion:    fileVersion,
+		objectData:     objectData,
+		name:           name,
+		lintConfig:     lintConfig,
+		breakingConfig: breakingConfig,
+		pluginConfigs:  pluginConfigs,
+	}, nil
+}
+
+func (p *bufPolicyYAMLFile) FileVersion() FileVersion {
+	return p.fileVersion
+}
+
+func (*bufPolicyYAMLFile) FileType() FileType {
+	return FileTypeBufYAML
+}
+
+func (p *bufPolicyYAMLFile) ObjectData() ObjectData {
+	return p.objectData
+}
+
+func (p *bufPolicyYAMLFile) Name() string {
+	return p.name
+}
+
+func (p *bufPolicyYAMLFile) LintConfig() LintConfig {
+	return p.lintConfig
+}
+
+func (p *bufPolicyYAMLFile) BreakingConfig() BreakingConfig {
+	return p.breakingConfig
+}
+
+func (p *bufPolicyYAMLFile) PluginConfigs() []PluginConfig {
+	return slices.Clone(p.pluginConfigs)
+}
+func (*bufPolicyYAMLFile) isBufPolicyYAMLFile() {}
+func (*bufPolicyYAMLFile) isFile()              {}
+func (*bufPolicyYAMLFile) isFileInfo()          {}
+
+// externalBufPolicyYAMLFileV2 represents the v2 buf.policy.yaml file.
+type externalBufPolicyYAMLFileV2 struct {
+	Version  string                                 `json:"version,omitempty" yaml:"version,omitempty"`
+	Name     string                                 `json:"name,omitempty" yaml:"name,omitempty"`
+	Lint     externalBufYAMLFileLintV2              `json:"lint,omitempty" yaml:"lint,omitempty"`
+	Breaking externalBufYAMLFileBreakingV1Beta1V1V2 `json:"breaking,omitempty" yaml:"breaking,omitempty"`
+	Plugins  []externalBufYAMLFilePluginV2          `json:"plugins,omitempty" yaml:"plugins,omitempty"`
+}
+
+func readBufPolicyYAMLFile(
+	data []byte,
+	objectData ObjectData,
+	allowJSON bool,
+) (BufPolicyYAMLFile, error) {
+	fileVersion, err := getFileVersionForData(data, allowJSON, true, bufPolicyYAMLFileNameToSupportedFileVersions, FileVersionV2, defaultBufPolicyYAMLFileVersion)
+	if err != nil {
+		return nil, err
+	}
+	if fileVersion != FileVersionV2 {
+		fmt.Println("objectData", objectData)
+		return nil, newUnsupportedFileVersionError(objectData.Name(), fileVersion)
+	}
+	var externalBufPolicyYAMLFile externalBufPolicyYAMLFileV2
+	if err := getUnmarshalStrict(allowJSON)(data, &externalBufPolicyYAMLFile); err != nil {
+		return nil, fmt.Errorf("invalid as version %v: %w", fileVersion, err)
+	}
+
+	var lintConfig LintConfig
+	if !externalBufPolicyYAMLFile.Lint.isEmpty() {
+		lintConfig, err = getLintConfigForExternalLintV2(
+			fileVersion,
+			externalBufPolicyYAMLFile.Lint,
+			".",   // Top-level directory always has the root ".".
+			false, // Not module-specific configuration.
+		)
+		if err != nil {
+			return nil, err
+		}
+	}
+	var breakingConfig BreakingConfig
+	if !externalBufPolicyYAMLFile.Breaking.isEmpty() {
+		breakingConfig, err = getBreakingConfigForExternalBreaking(
+			fileVersion,
+			externalBufPolicyYAMLFile.Breaking,
+			".",   // Top-level directory always has the root ".".
+			false, // Not module-specific configuration.
+		)
+		if err != nil {
+			return nil, err
+		}
+	}
+	var pluginConfigs []PluginConfig
+	for _, externalPluginConfig := range externalBufPolicyYAMLFile.Plugins {
+		pluginConfig, err := newPluginConfigForExternalV2(externalPluginConfig)
+		if err != nil {
+			return nil, err
+		}
+		pluginConfigs = append(pluginConfigs, pluginConfig)
+	}
+	return newBufPolicyYAMLFile(
+		fileVersion,
+		objectData,
+		externalBufPolicyYAMLFile.Name,
+		lintConfig,
+		breakingConfig,
+		pluginConfigs,
+	)
+}
+
+func writeBufPolicyYAMLFile(writer io.Writer, bufPolicyYAMLFile BufPolicyYAMLFile) error {
+	fileVersion := bufPolicyYAMLFile.FileVersion()
+	if fileVersion != FileVersionV2 {
+		// This is effectively a system error.
+		return syserror.Wrap(newUnsupportedFileVersionError("", fileVersion))
+	}
+	var externalLint externalBufYAMLFileLintV2
+	if lintConfig := bufPolicyYAMLFile.LintConfig(); lintConfig != nil {
+		externalLint = getExternalLintV2ForLintConfig(lintConfig, ".")
+	}
+	var externalBreaking externalBufYAMLFileBreakingV1Beta1V1V2
+	if breakingConfig := bufPolicyYAMLFile.BreakingConfig(); breakingConfig != nil {
+		externalBreaking = getExternalBreakingForBreakingConfig(breakingConfig, ".")
+	}
+	var externalPlugins []externalBufYAMLFilePluginV2
+	for _, pluginConfig := range bufPolicyYAMLFile.PluginConfigs() {
+		externalPlugin, err := newExternalV2ForPluginConfig(pluginConfig)
+		if err != nil {
+			return syserror.Wrap(err)
+		}
+		externalPlugins = append(externalPlugins, externalPlugin)
+	}
+	externalBufPolicyYAMLFile := externalBufPolicyYAMLFileV2{
+		Version:  fileVersion.String(),
+		Name:     bufPolicyYAMLFile.Name(),
+		Lint:     externalLint,
+		Breaking: externalBreaking,
+		Plugins:  externalPlugins,
+	}
+	data, err := encoding.MarshalYAML(&externalBufPolicyYAMLFile)
+	if err != nil {
+		return err
+	}
+	_, err = writer.Write(data)
+	return err
+}