otelconf: add unmarshalers for otlp exporters

Adding unmarshalers and tests for otlp http/grpc exporters. Also added a missing
test for createHeaders.

Part of splitting open-telemetry#8026

Signed-off-by: alex boten <[email protected]>

Author: codeboten

CHANGELOG.md

@@ -16,6 +16,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 - Add unmarshaling and validation for `CardinalityLimits` and `SpanLimits` to v1.0.0 model in `go.opentelemetry.io/contrib/otelconf`. (#8043)
 - Add unmarshaling and validation for `BatchLogRecordProcessor`, `BatchSpanProcessor`, and `PeriodicMetricReader` to v1.0.0 model in `go.opentelemetry.io/contrib/otelconf`. (#8049)
 - Add unmarshaling and validation for `TextMapPropagator` to v1.0.0 model in `go.opentelemetry.io/contrib/otelconf`. (#8052)
+- Add unmarshaling and validation for `OTLPHttpExporter`, `OTLPGrpcExporter`, `OTLPGrpcMetricExporter` and `OTLPHttpMetricExporter` to v1.0.0 model in `go.opentelemetry.io/contrib/otelconf`. (#)
 
 ### Changed
 

otelconf/config_common.go

@@ -52,16 +52,17 @@ func (e *errBound) Is(target error) bool {
 	return e.Field == t.Field && e.Bound == t.Bound && e.Op == t.Op
 }
 
-type errRequiredExporter struct {
+type errRequired struct {
 	Object any
+	Field  string
 }
 
-func (e *errRequiredExporter) Error() string {
-	return fmt.Sprintf("field exporter in %s: required", reflect.TypeOf(e.Object))
+func (e *errRequired) Error() string {
+	return fmt.Sprintf("field %s in %s: required", e.Field, reflect.TypeOf(e.Object))
 }
 
-func (e *errRequiredExporter) Is(target error) bool {
-	t, ok := target.(*errRequiredExporter)
+func (e *errRequired) Is(target error) bool {
+	t, ok := target.(*errRequired)
 	if !ok {
 		return false
 	}
@@ -96,9 +97,9 @@ func newErrGreaterThanZero(field string) error {
 	return &errBound{Field: field, Bound: 0, Op: ">"}
 }
 
-// newErrRequiredExporter creates a new error indicating that the exporter field is required.
-func newErrRequiredExporter(object any) error {
-	return &errRequiredExporter{Object: object}
+// newErrRequired creates a new error indicating that the exporter field is required.
+func newErrRequired(object any, field string) error {
+	return &errRequired{Object: object, Field: field}
 }
 
 // newErrUnmarshal creates a new error indicating that an error occurred during unmarshaling.

otelconf/config_json.go

@@ -273,7 +273,7 @@ func (j *BatchLogRecordProcessor) UnmarshalJSON(b []byte) error {
 		return errors.Join(newErrUnmarshal(j), err)
 	}
 	if sh.Exporter == nil {
-		return newErrRequiredExporter(j)
+		return newErrRequired(j, "exporter")
 	}
 	// Hydrate the exporter into the underlying field.
 	if err := json.Unmarshal(sh.Exporter, &sh.Plain.Exporter); err != nil {
@@ -299,7 +299,7 @@ func (j *BatchSpanProcessor) UnmarshalJSON(b []byte) error {
 		return errors.Join(newErrUnmarshal(j), err)
 	}
 	if sh.Exporter == nil {
-		return newErrRequiredExporter(j)
+		return newErrRequired(j, "exporter")
 	}
 	// Hydrate the exporter into the underlying field.
 	if err := json.Unmarshal(sh.Exporter, &sh.Plain.Exporter); err != nil {
@@ -325,7 +325,7 @@ func (j *PeriodicMetricReader) UnmarshalJSON(b []byte) error {
 		return errors.Join(newErrUnmarshal(j), err)
 	}
 	if sh.Exporter == nil {
-		return newErrRequiredExporter(j)
+		return newErrRequired(j, "exporter")
 	}
 	// Hydrate the exporter into the underlying field.
 	if err := json.Unmarshal(sh.Exporter, &sh.Plain.Exporter); err != nil {
@@ -366,3 +366,99 @@ func (j *SpanLimits) UnmarshalJSON(value []byte) error {
 	*j = SpanLimits(plain)
 	return nil
 }
+
+// UnmarshalJSON implements json.Unmarshaler.
+func (j *OTLPHttpMetricExporter) UnmarshalJSON(b []byte) error {
+	type Plain OTLPHttpMetricExporter
+	type shadow struct {
+		Plain
+		Endpoint json.RawMessage `json:"endpoint"`
+	}
+	var sh shadow
+	if err := json.Unmarshal(b, &sh); err != nil {
+		return errors.Join(newErrUnmarshal(j), err)
+	}
+	if sh.Endpoint == nil {
+		return newErrRequired(j, "endpoint")
+	}
+	if err := json.Unmarshal(sh.Endpoint, &sh.Plain.Endpoint); err != nil {
+		return err
+	}
+	if sh.Plain.Timeout != nil && 0 > *sh.Plain.Timeout {
+		return newErrGreaterOrEqualZero("timeout")
+	}
+	*j = OTLPHttpMetricExporter(sh.Plain)
+	return nil
+}
+
+// UnmarshalJSON implements json.Unmarshaler.
+func (j *OTLPGrpcMetricExporter) UnmarshalJSON(b []byte) error {
+	type Plain OTLPGrpcMetricExporter
+	type shadow struct {
+		Plain
+		Endpoint json.RawMessage `json:"endpoint"`
+	}
+	var sh shadow
+	if err := json.Unmarshal(b, &sh); err != nil {
+		return errors.Join(newErrUnmarshal(j), err)
+	}
+	if sh.Endpoint == nil {
+		return newErrRequired(j, "endpoint")
+	}
+	if err := json.Unmarshal(sh.Endpoint, &sh.Plain.Endpoint); err != nil {
+		return err
+	}
+	if sh.Plain.Timeout != nil && 0 > *sh.Plain.Timeout {
+		return newErrGreaterOrEqualZero("timeout")
+	}
+	*j = OTLPGrpcMetricExporter(sh.Plain)
+	return nil
+}
+
+// UnmarshalJSON implements json.Unmarshaler.
+func (j *OTLPHttpExporter) UnmarshalJSON(b []byte) error {
+	type Plain OTLPHttpExporter
+	type shadow struct {
+		Plain
+		Endpoint json.RawMessage `json:"endpoint"`
+	}
+	var sh shadow
+	if err := json.Unmarshal(b, &sh); err != nil {
+		return errors.Join(newErrUnmarshal(j), err)
+	}
+	if sh.Endpoint == nil {
+		return newErrRequired(j, "endpoint")
+	}
+	if err := json.Unmarshal(sh.Endpoint, &sh.Plain.Endpoint); err != nil {
+		return err
+	}
+	if sh.Plain.Timeout != nil && 0 > *sh.Plain.Timeout {
+		return newErrGreaterOrEqualZero("timeout")
+	}
+	*j = OTLPHttpExporter(sh.Plain)
+	return nil
+}
+
+// UnmarshalJSON implements json.Unmarshaler.
+func (j *OTLPGrpcExporter) UnmarshalJSON(b []byte) error {
+	type Plain OTLPGrpcExporter
+	type shadow struct {
+		Plain
+		Endpoint json.RawMessage `json:"endpoint"`
+	}
+	var sh shadow
+	if err := json.Unmarshal(b, &sh); err != nil {
+		return errors.Join(newErrUnmarshal(j), err)
+	}
+	if sh.Endpoint == nil {
+		return newErrRequired(j, "endpoint")
+	}
+	if err := json.Unmarshal(sh.Endpoint, &sh.Plain.Endpoint); err != nil {
+		return err
+	}
+	if sh.Plain.Timeout != nil && 0 > *sh.Plain.Timeout {
+		return newErrGreaterOrEqualZero("timeout")
+	}
+	*j = OTLPGrpcExporter(sh.Plain)
+	return nil
+}