Add Cargo Registry support to buf.plugin.yaml (#2956)

private/bufpkg/bufplugin/bufplugin.go

@@ -78,6 +78,8 @@ func PluginToProtoPluginRegistryType(plugin Plugin) registryv1alpha1.PluginRegis
 			registryType = registryv1alpha1.PluginRegistryType_PLUGIN_REGISTRY_TYPE_SWIFT
 		} else if plugin.Registry().Python != nil {
 			registryType = registryv1alpha1.PluginRegistryType_PLUGIN_REGISTRY_TYPE_PYTHON
+		} else if plugin.Registry().Cargo != nil {
+			registryType = registryv1alpha1.PluginRegistryType_PLUGIN_REGISTRY_TYPE_CARGO
 		}
 	}
 	return registryType
@@ -195,6 +197,12 @@ func PluginRegistryToProtoRegistryConfig(pluginRegistry *bufpluginconfig.Registr
 			return nil, err
 		}
 		registryConfig.RegistryConfig = &registryv1alpha1.RegistryConfig_PythonConfig{PythonConfig: pythonConfig}
+	} else if pluginRegistry.Cargo != nil {
+		cargoConfig, err := CargoRegistryConfigToProtoCargoConfig(pluginRegistry.Cargo)
+		if err != nil {
+			return nil, err
+		}
+		registryConfig.RegistryConfig = &registryv1alpha1.RegistryConfig_CargoConfig{CargoConfig: cargoConfig}
 	}
 	return registryConfig, nil
 }
@@ -264,10 +272,49 @@ func ProtoRegistryConfigToPluginRegistry(config *registryv1alpha1.RegistryConfig
 			return nil, err
 		}
 		registryConfig.Python = pythonConfig
+	} else if protoCargoConfig := config.GetCargoConfig(); protoCargoConfig != nil {
+		cargoConfig, err := ProtoCargoConfigToCargoRegistryConfig(protoCargoConfig)
+		if err != nil {
+			return nil, err
+		}
+		registryConfig.Cargo = cargoConfig
 	}
 	return registryConfig, nil
 }
 
+// ProtoCargoConfigToCargoRegistryConfig converts protoCargoConfig to an equivalent [*bufpluginconfig.CargoRegistryConfig].
+func ProtoCargoConfigToCargoRegistryConfig(protoCargoConfig *registryv1alpha1.CargoConfig) (*bufpluginconfig.CargoRegistryConfig, error) {
+	cargoConfig := &bufpluginconfig.CargoRegistryConfig{
+		RustVersion: protoCargoConfig.RustVersion,
+	}
+	for _, dependency := range protoCargoConfig.RuntimeLibraries {
+		cargoConfig.Deps = append(cargoConfig.Deps, bufpluginconfig.CargoRegistryDependency{
+			Name:               dependency.Name,
+			VersionRequirement: dependency.VersionRequirement,
+			DefaultFeatures:    dependency.DefaultFeatures,
+			Features:           dependency.Features,
+		})
+	}
+	return cargoConfig, nil
+}
+
+// CargoRegistryConfigToProtoCargoConfig converts cargoConfig to an equivalent [*registryv1alpha1.CargoConfig].
+func CargoRegistryConfigToProtoCargoConfig(cargoConfig *bufpluginconfig.CargoRegistryConfig) (*registryv1alpha1.CargoConfig, error) {
+	protoCargoConfig := &registryv1alpha1.CargoConfig{
+		RustVersion: cargoConfig.RustVersion,
+	}
+	for _, dependency := range cargoConfig.Deps {
+		protoCargoConfig.RuntimeLibraries = append(protoCargoConfig.RuntimeLibraries, &registryv1alpha1.CargoConfig_RuntimeLibrary{
+			Name:               dependency.Name,
+			VersionRequirement: dependency.VersionRequirement,
+			DefaultFeatures:    dependency.DefaultFeatures,
+			Features:           dependency.Features,
+		})
+	}
+	return protoCargoConfig, nil
+}
+
+// ProtoPythonConfigToPythonRegistryConfig converts protoPythonConfig to an equivalent [*bufpluginconfig.PythonRegistryConfig].
 func ProtoPythonConfigToPythonRegistryConfig(protoPythonConfig *registryv1alpha1.PythonConfig) (*bufpluginconfig.PythonRegistryConfig, error) {
 	pythonConfig := &bufpluginconfig.PythonRegistryConfig{
 		RequiresPython: protoPythonConfig.RequiresPython,
@@ -286,6 +333,7 @@ func ProtoPythonConfigToPythonRegistryConfig(protoPythonConfig *registryv1alpha1
 	return pythonConfig, nil
 }
 
+// PythonRegistryConfigToProtoPythonConfig converts pythonConfig to an equivalent [*registryv1alpha1.PythonConfig].
 func PythonRegistryConfigToProtoPythonConfig(pythonConfig *bufpluginconfig.PythonRegistryConfig) (*registryv1alpha1.PythonConfig, error) {
 	protoPythonConfig := &registryv1alpha1.PythonConfig{
 		RequiresPython: pythonConfig.RequiresPython,
@@ -306,6 +354,7 @@ func PythonRegistryConfigToProtoPythonConfig(pythonConfig *bufpluginconfig.Pytho
 	return protoPythonConfig, nil
 }
 
+// ProtoSwiftConfigToSwiftRegistryConfig converts protoSwiftConfig to an equivalent [*bufpluginconfig.SwiftRegistryConfig].
 func ProtoSwiftConfigToSwiftRegistryConfig(protoSwiftConfig *registryv1alpha1.SwiftConfig) (*bufpluginconfig.SwiftRegistryConfig, error) {
 	swiftConfig := &bufpluginconfig.SwiftRegistryConfig{}
 	runtimeLibs := protoSwiftConfig.GetRuntimeLibraries()
@@ -340,6 +389,7 @@ func ProtoSwiftConfigToSwiftRegistryConfig(protoSwiftConfig *registryv1alpha1.Sw
 	return swiftConfig, nil
 }
 
+// SwiftRegistryConfigToProtoSwiftConfig converts swiftConfig to an equivalent [*registryv1alpha1.SwiftConfig].
 func SwiftRegistryConfigToProtoSwiftConfig(swiftConfig *bufpluginconfig.SwiftRegistryConfig) *registryv1alpha1.SwiftConfig {
 	protoSwiftConfig := &registryv1alpha1.SwiftConfig{}
 	if swiftConfig.Dependencies != nil {

private/bufpkg/bufplugin/bufplugin_test.go

@@ -174,6 +174,19 @@ func TestPluginRegistryRoundTrip(t *testing.T) {
 			},
 		},
 	})
+	assertPluginRegistryRoundTrip(t, &bufpluginconfig.RegistryConfig{
+		Cargo: &bufpluginconfig.CargoRegistryConfig{
+			RustVersion: "1.60",
+			Deps: []bufpluginconfig.CargoRegistryDependency{
+				{
+					Name:               "prost",
+					VersionRequirement: "0.12.3",
+					DefaultFeatures:    true,
+					Features:           []string{"some/feature"},
+				},
+			},
+		},
+	})
 }
 
 func assertPluginRegistryRoundTrip(t testing.TB, config *bufpluginconfig.RegistryConfig) {

private/bufpkg/bufplugin/bufpluginconfig/bufpluginconfig.go

@@ -92,6 +92,7 @@ type RegistryConfig struct {
 	Maven  *MavenRegistryConfig
 	Swift  *SwiftRegistryConfig
 	Python *PythonRegistryConfig
+	Cargo  *CargoRegistryConfig
 	// Options is the set of options passed into the plugin for the
 	// remote registry.
 	//
@@ -241,6 +242,31 @@ type PythonRegistryConfig struct {
 	PackageType string
 }
 
+// CargoRegistryDependency defines a runtime dependency for a generated crate.
+// It is the subset of a full Cargo dependency specification, which contains
+// fields that are currently irrelevant for Generated SDKs.
+// Ref: https://doc.rust-lang.org/cargo/reference/specifying-dependencies.html
+type CargoRegistryDependency struct {
+	// Name specifies the name of the dependency.
+	Name string
+	// VersionRequirement specifies the version requirement of the dependency.
+	VersionRequirement string
+	// DefaultFeatures specifies whether or not the default features will
+	// be enabled for the dependency.
+	DefaultFeatures bool
+	// Features specifies the features enabled for the dependency.
+	Features []string
+}
+
+// CargoRegistryConfig is the registry configuration for a Cargo plugin.
+type CargoRegistryConfig struct {
+	// RustVersion specifies the minimum supported Rust version (MSRV) for the generated crate.
+	// Ref: https://doc.rust-lang.org/cargo/reference/manifest.html#the-rust-version-field
+	RustVersion string
+	// Deps specifies the runtime dependencies of the crate.
+	Deps []CargoRegistryDependency
+}
+
 // ConfigOption is an optional option used when loading a Config.
 type ConfigOption func(*configOptions)
 
@@ -371,6 +397,7 @@ type ExternalRegistryConfig struct {
 	Maven  *ExternalMavenRegistryConfig  `json:"maven,omitempty" yaml:"maven,omitempty"`
 	Swift  *ExternalSwiftRegistryConfig  `json:"swift,omitempty" yaml:"swift,omitempty"`
 	Python *ExternalPythonRegistryConfig `json:"python,omitempty" yaml:"python,omitempty"`
+	Cargo  *ExternalCargoRegistryConfig  `json:"cargo,omitempty" yaml:"cargo,omitempty"`
 	Opts   []string                      `json:"opts,omitempty" yaml:"opts,omitempty"`
 }
 
@@ -479,6 +506,7 @@ type ExternalSwiftRegistryDependencyPlatformConfig struct {
 	WatchOS string `json:"watchos,omitempty" yaml:"watchos,omitempty"`
 }
 
+// ExternalPythonRegistryConfig is the registry configuration for a Python plugin.
 type ExternalPythonRegistryConfig struct {
 	// Deps are dependency specifications for the generated SDK.
 	Deps []string `json:"deps,omitempty" yaml:"deps,omitempty"`
@@ -489,6 +517,28 @@ type ExternalPythonRegistryConfig struct {
 	PackageType string `json:"package_type,omitempty" yaml:"package_type,omitempty"`
 }
 
+// ExternalCargoDependency specifies a runtime dependency for a Cargo generated SDK.
+type ExternalCargoDependency struct {
+	// Name specifies the name of the dependency.
+	Name string `json:"name,omitempty" yaml:"name,omitempty"`
+	// VersionRequirement specifies the version requirement of the dependency.
+	VersionRequirement string `json:"req,omitempty" yaml:"req,omitempty"`
+	// DefaultFeatures specifies whether or not the default features will
+	// be enabled for the dependency.
+	DefaultFeatures bool `json:"default_features,omitempty" yaml:"default_features,omitempty"`
+	// Features specifies the features enabled for the dependency.
+	Features []string `json:"features,omitempty" yaml:"features,omitempty"`
+}
+
+// ExternalCargoRegistryConfig is the registry configuration for a Rust plugin.
+type ExternalCargoRegistryConfig struct {
+	// RustVersion specifies the minimum supported Rust version (MSRV) for the generated crate.
+	// Ref: https://doc.rust-lang.org/cargo/reference/manifest.html#the-rust-version-field
+	RustVersion string `json:"rust_version,omitempty" yaml:"rust_version,omitempty"`
+	// Deps specifies the dependencies for the generated SDK.
+	Deps []ExternalCargoDependency `json:"deps,omitempty" yaml:"deps,omitempty"`
+}
+
 type externalConfigVersion struct {
 	Version string `json:"version,omitempty" yaml:"version,omitempty"`
 }

private/bufpkg/bufplugin/bufpluginconfig/bufpluginconfig_test.go

@@ -328,6 +328,41 @@ func TestParsePluginConfigPythonYAML(t *testing.T) {
 	)
 }
 
+func TestParsePluginConfigCargoYAML(t *testing.T) {
+	t.Parallel()
+	pluginConfig, err := ParseConfig(filepath.Join("testdata", "success", "cargo", "buf.plugin.yaml"))
+	require.NoError(t, err)
+	pluginIdentity, err := bufpluginref.PluginIdentityForString("buf.build/community/neoeinstein-prost")
+	require.NoError(t, err)
+	require.Equal(
+		t,
+		&Config{
+			Name:            pluginIdentity,
+			PluginVersion:   "v0.3.1",
+			SourceURL:       "https://github.com/neoeinstein/protoc-gen-prost",
+			Description:     "Generates code using the Prost! code generation engine.",
+			SPDXLicenseID:   "Apache-2.0",
+			LicenseURL:      "https://github.com/neoeinstein/protoc-gen-prost/blob/protoc-gen-prost-v0.3.1/LICENSE",
+			OutputLanguages: []string{"rust"},
+			Registry: &RegistryConfig{
+				Cargo: &CargoRegistryConfig{
+					RustVersion: "1.60",
+					Deps: []CargoRegistryDependency{
+						{
+							Name:               "prost",
+							VersionRequirement: "0.12.3",
+							DefaultFeatures:    true,
+							Features:           []string{"a-feature"},
+						},
+					},
+				},
+				Options: map[string]string{"enable_type_names": "true"},
+			},
+		},
+		pluginConfig,
+	)
+}
+
 func TestParsePluginConfigOptionsYAML(t *testing.T) {
 	t.Parallel()
 	pluginConfig, err := ParseConfig(filepath.Join("testdata", "success", "options", "buf.plugin.yaml"))

private/bufpkg/bufplugin/bufpluginconfig/config.go

@@ -92,6 +92,7 @@ func newRegistryConfig(externalRegistryConfig ExternalRegistryConfig) (*Registry
 		isMavenEmpty  = externalRegistryConfig.Maven == nil
 		isSwiftEmpty  = externalRegistryConfig.Swift == nil
 		isPythonEmpty = externalRegistryConfig.Python == nil
+		isCargoEmpty  = externalRegistryConfig.Cargo == nil
 	)
 	var registryCount int
 	for _, isEmpty := range []bool{
@@ -100,6 +101,7 @@ func newRegistryConfig(externalRegistryConfig ExternalRegistryConfig) (*Registry
 		isMavenEmpty,
 		isSwiftEmpty,
 		isPythonEmpty,
+		isCargoEmpty,
 	} {
 		if !isEmpty {
 			registryCount++
@@ -161,6 +163,15 @@ func newRegistryConfig(externalRegistryConfig ExternalRegistryConfig) (*Registry
 			Python:  pythonRegistryConfig,
 			Options: options,
 		}, nil
+	case !isCargoEmpty:
+		cargoRegistryConfig, err := newCargoRegistryConfig(externalRegistryConfig.Cargo)
+		if err != nil {
+			return nil, err
+		}
+		return &RegistryConfig{
+			Cargo:   cargoRegistryConfig,
+			Options: options,
+		}, nil
 	default:
 		return nil, errors.New("unknown registry configuration")
 	}
@@ -357,6 +368,25 @@ func newPythonRegistryConfig(externalPythonRegistryConfig *ExternalPythonRegistr
 	}, nil
 }
 
+func newCargoRegistryConfig(externalCargoRegistryConfig *ExternalCargoRegistryConfig) (*CargoRegistryConfig, error) {
+	if externalCargoRegistryConfig == nil {
+		return nil, nil
+	}
+	config := &CargoRegistryConfig{
+		RustVersion: externalCargoRegistryConfig.RustVersion,
+	}
+	for _, dependency := range externalCargoRegistryConfig.Deps {
+		if dependency.Name == "" {
+			return nil, fmt.Errorf("cargo registry dependency cannot have empty name")
+		}
+		if dependency.VersionRequirement == "" {
+			return nil, fmt.Errorf("cargo registry dependency cannot have empty req")
+		}
+		config.Deps = append(config.Deps, CargoRegistryDependency(dependency))
+	}
+	return config, nil
+}
+
 func pluginIdentityForStringWithOverrideRemote(identityStr string, overrideRemote string) (bufpluginref.PluginIdentity, error) {
 	identity, err := bufpluginref.PluginIdentityForString(identityStr)
 	if err != nil {

private/bufpkg/bufplugin/bufpluginconfig/testdata/success/cargo/buf.plugin.yaml

@@ -0,0 +1,26 @@
+version: v1
+name: buf.build/community/neoeinstein-prost
+plugin_version: v0.3.1
+source_url: https://github.com/neoeinstein/protoc-gen-prost
+description: Generates code using the Prost! code generation engine.
+output_languages:
+  - rust
+spdx_license_id: Apache-2.0
+license_url: https://github.com/neoeinstein/protoc-gen-prost/blob/protoc-gen-prost-v0.3.1/LICENSE
+registry:
+  # NOTE: This configuration does not perfectly match with the version in
+  # plugins, because we want values to be set to check for round-tripping.
+  cargo:
+    # https://github.com/neoeinstein/protoc-gen-prost/blob/protoc-gen-prost-v0.3.1/protoc-gen-prost/Cargo.toml#L21
+    # https://github.com/tokio-rs/prost/blob/v0.12.3/prost-build/Cargo.toml#L15
+    rust_version: "1.60"
+    deps:
+      # https://github.com/tokio-rs/prost/blob/v0.12.3/prost-build/Cargo.toml#L30
+      - name: prost
+        req: "0.12.3"
+        default_features: true
+        features: ["a-feature"]
+  # https://github.com/neoeinstein/protoc-gen-prost/tree/protoc-gen-prost-v0.3.1/protoc-gen-prost#options
+  opts:
+    # `Any` support.
+    - enable_type_names=true