[configoptional] Validate nested types

.chloggen/configoptional-validate.yaml

@@ -0,0 +1,25 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: bug_fix
+
+# The name of the component, or a single word describing the area of concern, (e.g. otlpreceiver)
+component: configoptional
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Allow validating nested types
+
+# One or more tracking issues or pull requests related to the change
+issues: [13579]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext: '`configoptional.Optional` now implements `xconfmap.Validator`'
+
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user, api]

config/configgrpc/go.mod

@@ -53,6 +53,7 @@ require (
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	go.opentelemetry.io/auto/sdk v1.1.0 // indirect
 	go.opentelemetry.io/collector/confmap v1.38.0 // indirect
+	go.opentelemetry.io/collector/confmap/xconfmap v0.132.0 // indirect
 	go.opentelemetry.io/collector/featuregate v1.38.0 // indirect
 	go.opentelemetry.io/collector/internal/telemetry v0.132.0 // indirect
 	go.opentelemetry.io/collector/pdata/pprofile v0.132.0 // indirect
@@ -119,3 +120,5 @@ replace go.opentelemetry.io/collector/featuregate => ../../featuregate
 replace go.opentelemetry.io/collector/extension/extensionmiddleware/extensionmiddlewaretest => ../../extension/extensionmiddleware/extensionmiddlewaretest
 
 replace go.opentelemetry.io/collector/confmap => ../../confmap
+
+replace go.opentelemetry.io/collector/confmap/xconfmap => ../../confmap/xconfmap

config/confighttp/xconfighttp/go.mod

@@ -47,6 +47,7 @@ require (
 	go.opentelemetry.io/collector/config/configoptional v0.132.0 // indirect
 	go.opentelemetry.io/collector/config/configtls v1.38.0 // indirect
 	go.opentelemetry.io/collector/confmap v1.38.0 // indirect
+	go.opentelemetry.io/collector/confmap/xconfmap v0.132.0 // indirect
 	go.opentelemetry.io/collector/extension/extensionauth v1.38.0 // indirect
 	go.opentelemetry.io/collector/extension/extensionmiddleware v0.132.0 // indirect
 	go.opentelemetry.io/collector/featuregate v1.38.0 // indirect

config/configoptional/go.mod

@@ -5,6 +5,7 @@ go 1.24
 require (
 	github.com/stretchr/testify v1.10.0
 	go.opentelemetry.io/collector/confmap v1.38.0
+	go.opentelemetry.io/collector/confmap/xconfmap v0.132.0
 	go.uber.org/goleak v1.3.0
 )
 
@@ -29,3 +30,5 @@ require (
 replace go.opentelemetry.io/collector/confmap => ../../confmap
 
 replace go.opentelemetry.io/collector/featuregate => ../../featuregate
+
+replace go.opentelemetry.io/collector/confmap/xconfmap => ../../confmap/xconfmap

config/configoptional/optional.go

@@ -10,6 +10,7 @@ import (
 	"strings"
 
 	"go.opentelemetry.io/collector/confmap"
+	"go.opentelemetry.io/collector/confmap/xconfmap"
 )
 
 type flavor int
@@ -189,3 +190,26 @@ func (o Optional[T]) Marshal(conf *confmap.Conf) error {
 
 	return nil
 }
+
+var _ xconfmap.Validator = (*Optional[any])(nil)
+
+// Validate implements [xconfmap.Validator]. This is required because the
+// private fields in [xconfmap.Validator] can't be seen by the reflection used
+// by [xconfmap.Validate], and therefore we have to continue the validation
+// chain manually. This method isn't meant to be called directly, and should
+// generally only be called by [xconfmap.Validate].
+func (o *Optional[T]) Validate() error {
+	// When the flavor is None, the user has not passed this value,
+	// and therefore we should not validate it. The parent struct holding
+	// the Optional type can determine whether a None value is valid for
+	// a given config.
+	//
+	// If the flavor is still Default, then the user has not passed this
+	// value and we should also not validate it.
+	if o.flavor == noneFlavor || o.flavor == defaultFlavor {
+		return nil
+	}
+
+	// For the some flavor, validate the actual value.
+	return xconfmap.Validate(o.value)
+}

config/configoptional/optional_test.go

@@ -4,13 +4,16 @@
 package configoptional
 
 import (
+	"errors"
 	"fmt"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
 	"go.opentelemetry.io/collector/confmap"
+	"go.opentelemetry.io/collector/confmap/confmaptest"
+	"go.opentelemetry.io/collector/confmap/xconfmap"
 )
 
 type Config[T any] struct {
@@ -460,3 +463,123 @@ func TestComparePointerMarshal(t *testing.T) {
 		})
 	}
 }
+
+type invalid struct{}
+
+func (invalid) Validate() error {
+	return errors.New("invalid")
+}
+
+var _ xconfmap.Validator = invalid{}
+
+type hasNested struct {
+	CouldBe Optional[invalid]
+}
+
+func TestOptionalValidate(t *testing.T) {
+	require.NoError(t, xconfmap.Validate(hasNested{
+		CouldBe: None[invalid](),
+	}))
+	require.NoError(t, xconfmap.Validate(hasNested{
+		CouldBe: Default(invalid{}),
+	}))
+	require.Error(t, xconfmap.Validate(hasNested{
+		CouldBe: Some(invalid{}),
+	}))
+}
+
+type validatedConfig struct {
+	Default Optional[optionalConfig] `mapstructure:"default"`
+	Some    Optional[someConfig]     `mapstructure:"some"`
+}
+
+var _ xconfmap.Validator = (*optionalConfig)(nil)
+
+type optionalConfig struct {
+	StringVal string `mapstructure:"string_val"`
+}
+
+func (n optionalConfig) Validate() error {
+	if n.StringVal == "invalid" {
+		return errors.New("field `string_val` cannot be set to `invalid`")
+	}
+
+	return nil
+}
+
+type someConfig struct {
+	Nested Optional[optionalConfig] `mapstructure:"nested"`
+}
+
+func newDefaultValidatedConfig() validatedConfig {
+	return validatedConfig{
+		Default: Default(optionalConfig{StringVal: "valid"}),
+	}
+}
+
+func newInvalidDefaultConfig() validatedConfig {
+	return validatedConfig{
+		Default: Default(optionalConfig{StringVal: "invalid"}),
+	}
+}
+
+func TestOptionalFileValidate(t *testing.T) {
+	cases := []struct {
+		name    string
+		variant string
+		cfg     func() validatedConfig
+		err     error
+	}{
+		{
+			name:    "valid default with just key set and no subfields",
+			variant: "implicit",
+			cfg:     newDefaultValidatedConfig,
+		},
+		{
+			name:    "valid default with keys set in default",
+			variant: "explicit",
+			cfg:     newDefaultValidatedConfig,
+		},
+		{
+			name:    "invalid config",
+			variant: "invalid",
+			cfg:     newDefaultValidatedConfig,
+			err:     errors.New("default: field `string_val` cannot be set to `invalid`\nsome: nested: field `string_val` cannot be set to `invalid`"),
+		},
+		{
+			name:    "invalid default throws an error",
+			variant: "implicit",
+			cfg:     newInvalidDefaultConfig,
+			err:     errors.New("default: field `string_val` cannot be set to `invalid`"),
+		},
+		{
+			name:    "invalid default does not throw an error when key is not set",
+			variant: "no_default",
+			cfg:     newInvalidDefaultConfig,
+		},
+		{
+			name:    "invalid default invalid default does not throw an error when the value is overridden",
+			variant: "explicit",
+			cfg:     newInvalidDefaultConfig,
+		},
+	}
+
+	for _, tt := range cases {
+		t.Run(tt.name, func(t *testing.T) {
+			conf, err := confmaptest.LoadConf(fmt.Sprintf("testdata/validate_%s.yaml", tt.variant))
+			require.NoError(t, err)
+
+			cfg := tt.cfg()
+
+			err = conf.Unmarshal(&cfg)
+			require.NoError(t, err)
+
+			err = xconfmap.Validate(cfg)
+			if tt.err == nil {
+				require.NoError(t, err)
+			} else {
+				require.EqualError(t, err, tt.err.Error())
+			}
+		})
+	}
+}

config/configoptional/testdata/validate_explicit.yaml

@@ -0,0 +1,5 @@
+default:
+  string_val: valid
+some:
+  nested:
+    string_val: valid

config/configoptional/testdata/validate_implicit.yaml

@@ -0,0 +1,4 @@
+default:
+some:
+  nested:
+    string_val: value1

config/configoptional/testdata/validate_invalid.yaml

@@ -0,0 +1,5 @@
+default:
+  string_val: invalid
+some:
+  nested:
+    string_val: invalid

config/configoptional/testdata/validate_no_default.yaml

@@ -0,0 +1,3 @@
+some:
+  nested:
+    string_val: value1

exporter/debugexporter/go.mod

@@ -45,6 +45,7 @@ require (
 	go.opentelemetry.io/collector/client v1.38.0 // indirect
 	go.opentelemetry.io/collector/config/configoptional v0.132.0 // indirect
 	go.opentelemetry.io/collector/config/configretry v1.38.0 // indirect
+	go.opentelemetry.io/collector/confmap/xconfmap v0.132.0 // indirect
 	go.opentelemetry.io/collector/consumer/consumererror v0.132.0 // indirect
 	go.opentelemetry.io/collector/consumer/consumererror/xconsumererror v0.132.0 // indirect
 	go.opentelemetry.io/collector/consumer/consumertest v0.132.0 // indirect
@@ -134,3 +135,5 @@ replace go.opentelemetry.io/collector/client => ../../client
 replace go.opentelemetry.io/collector/pdata/xpdata => ../../pdata/xpdata
 
 replace go.opentelemetry.io/collector/config/configoptional => ../../config/configoptional
+
+replace go.opentelemetry.io/collector/confmap/xconfmap => ../../confmap/xconfmap

exporter/exporterhelper/internal/queuebatch/config_test.go

@@ -11,67 +11,76 @@ import (
 	"github.com/stretchr/testify/require"
 
 	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/confmap/xconfmap"
 	"go.opentelemetry.io/collector/exporter/exporterhelper/internal/request"
 )
 
 func TestConfig_Validate(t *testing.T) {
 	cfg := newTestConfig()
-	require.NoError(t, cfg.Validate())
+	require.NoError(t, xconfmap.Validate(cfg))
 
 	cfg.NumConsumers = 0
-	require.EqualError(t, cfg.Validate(), "`num_consumers` must be positive")
+	require.EqualError(t, xconfmap.Validate(cfg), "`num_consumers` must be positive")
 
 	cfg = newTestConfig()
 	cfg.QueueSize = 0
-	require.EqualError(t, cfg.Validate(), "`queue_size` must be positive")
+	require.EqualError(t, xconfmap.Validate(cfg), "`queue_size` must be positive")
 
 	cfg = newTestConfig()
 	cfg.QueueSize = 0
-	require.EqualError(t, cfg.Validate(), "`queue_size` must be positive")
+	require.EqualError(t, xconfmap.Validate(cfg), "`queue_size` must be positive")
 
 	storageID := component.MustNewID("test")
 	cfg = newTestConfig()
 	cfg.WaitForResult = true
 	cfg.StorageID = &storageID
-	require.EqualError(t, cfg.Validate(), "`wait_for_result` is not supported with a persistent queue configured with `storage`")
+	require.EqualError(t, xconfmap.Validate(cfg), "`wait_for_result` is not supported with a persistent queue configured with `storage`")
 
 	cfg = newTestConfig()
 	cfg.QueueSize = cfg.Batch.Get().MinSize - 1
-	require.EqualError(t, cfg.Validate(), "`min_size` must be less than or equal to `queue_size`")
+	require.EqualError(t, xconfmap.Validate(cfg), "`min_size` must be less than or equal to `queue_size`")
+
+	cfg = newTestConfig()
+	cfg.Batch.Get().Sizer = request.SizerType{}
+	require.EqualError(t, xconfmap.Validate(cfg), "batch: `batch` supports only `items` or `bytes` sizer")
 
 	cfg = newTestConfig()
 	cfg.Sizer = request.SizerTypeBytes
-	require.NoError(t, cfg.Validate())
+	require.NoError(t, xconfmap.Validate(cfg))
 
 	// Confirm Validate doesn't return error with invalid config when feature is disabled
 	cfg.Enabled = false
-	assert.NoError(t, cfg.Validate())
+	assert.NoError(t, xconfmap.Validate(cfg))
 }
 
 func TestBatchConfig_Validate(t *testing.T) {
 	cfg := newTestBatchConfig()
-	require.NoError(t, cfg.Validate())
+	require.NoError(t, xconfmap.Validate(cfg))
 
 	cfg = newTestBatchConfig()
 	cfg.FlushTimeout = 0
-	require.EqualError(t, cfg.Validate(), "`flush_timeout` must be positive")
+	require.EqualError(t, xconfmap.Validate(cfg), "`flush_timeout` must be positive")
 
 	cfg = newTestBatchConfig()
 	cfg.MinSize = -1
-	require.EqualError(t, cfg.Validate(), "`min_size` must be non-negative")
+	require.EqualError(t, xconfmap.Validate(cfg), "`min_size` must be non-negative")
 
 	cfg = newTestBatchConfig()
 	cfg.MaxSize = -1
-	require.EqualError(t, cfg.Validate(), "`max_size` must be non-negative")
+	require.EqualError(t, xconfmap.Validate(cfg), "`max_size` must be non-negative")
 
 	cfg = newTestBatchConfig()
 	cfg.Sizer = request.SizerTypeRequests
-	require.EqualError(t, cfg.Validate(), "`batch` supports only `items` or `bytes` sizer")
+	require.EqualError(t, xconfmap.Validate(cfg), "`batch` supports only `items` or `bytes` sizer")
+
+	cfg = newTestBatchConfig()
+	cfg.Sizer = request.SizerType{}
+	require.EqualError(t, xconfmap.Validate(cfg), "`batch` supports only `items` or `bytes` sizer")
 
 	cfg = newTestBatchConfig()
 	cfg.MinSize = 2048
 	cfg.MaxSize = 1024
-	require.EqualError(t, cfg.Validate(), "`max_size` must be greater or equal to `min_size`")
+	require.EqualError(t, xconfmap.Validate(cfg), "`max_size` must be greater or equal to `min_size`")
 }
 
 func newTestBatchConfig() BatchConfig {

exporter/exporterhelper/xexporterhelper/go.mod

@@ -48,6 +48,7 @@ require (
 	go.opentelemetry.io/collector/config/configoptional v0.132.0 // indirect
 	go.opentelemetry.io/collector/config/configretry v1.38.0 // indirect
 	go.opentelemetry.io/collector/confmap v1.38.0 // indirect
+	go.opentelemetry.io/collector/confmap/xconfmap v0.132.0 // indirect
 	go.opentelemetry.io/collector/extension v1.38.0 // indirect
 	go.opentelemetry.io/collector/extension/xextension v0.132.0 // indirect
 	go.opentelemetry.io/collector/featuregate v1.38.0 // indirect
@@ -127,3 +128,5 @@ replace go.opentelemetry.io/collector/pdata/xpdata => ../../../pdata/xpdata
 replace go.opentelemetry.io/collector/config/configoptional => ../../../config/configoptional
 
 replace go.opentelemetry.io/collector/confmap => ../../../confmap
+
+replace go.opentelemetry.io/collector/confmap/xconfmap => ../../../confmap/xconfmap

exporter/exportertest/go.mod

@@ -43,6 +43,7 @@ require (
 	go.opentelemetry.io/collector/client v1.38.0 // indirect
 	go.opentelemetry.io/collector/config/configoptional v0.132.0 // indirect
 	go.opentelemetry.io/collector/confmap v1.38.0 // indirect
+	go.opentelemetry.io/collector/confmap/xconfmap v0.132.0 // indirect
 	go.opentelemetry.io/collector/consumer/xconsumer v0.132.0 // indirect
 	go.opentelemetry.io/collector/extension v1.38.0 // indirect
 	go.opentelemetry.io/collector/extension/xextension v0.132.0 // indirect
@@ -117,3 +118,5 @@ replace go.opentelemetry.io/collector/pdata/xpdata => ../../pdata/xpdata
 replace go.opentelemetry.io/collector/config/configoptional => ../../config/configoptional
 
 replace go.opentelemetry.io/collector/confmap => ../../confmap
+
+replace go.opentelemetry.io/collector/confmap/xconfmap => ../../confmap/xconfmap