add metric reader

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

Author: codeboten

CHANGELOG.md

@@ -18,7 +18,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 - 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`. (#8112)
 - Add a `WithSpanNameFormatter` option to `go.opentelemetry.io/contrib/instrumentation/go.mongodb.org/mongo-driver/v2/mongo/otelmongo`. (#7986)
-- Add unmarshaling and validation for `AttributeType`, `AttributeNameValue`, `SimpleSpanProcessor`, `SimpleLogRecordProcessor`, `ZipkinSpanExporter`, `NameStringValuePair`, `InstrumentType`, `ExperimentalPeerInstrumentationServiceMappingElem`, `ExporterDefaultHistogramAggregation` to v1.0.0 model in `go.opentelemetry.io/contrib/otelconf`. (#8127)
+- Add unmarshaling and validation for `AttributeType`, `AttributeNameValue`, `SimpleSpanProcessor`, `SimpleLogRecordProcessor`, `ZipkinSpanExporter`, `NameStringValuePair`, `InstrumentType`, `ExperimentalPeerInstrumentationServiceMappingElem`, `ExporterDefaultHistogramAggregation`, `PullMetricReader` to v1.0.0 model in `go.opentelemetry.io/contrib/otelconf`. (#8127)
 
 ### Changed
 

otelconf/config_json.go

@@ -692,3 +692,25 @@ func (j *ExporterDefaultHistogramAggregation) UnmarshalJSON(b []byte) error {
 	*j = ExporterDefaultHistogramAggregation(v)
 	return nil
 }
+
+// UnmarshalJSON implements json.Unmarshaler.
+func (j *PullMetricReader) UnmarshalJSON(b []byte) error {
+	type Plain PullMetricReader
+	type shadow struct {
+		Plain
+		Exporter json.RawMessage `json:"exporter"`
+	}
+	var sh shadow
+	if err := json.Unmarshal(b, &sh); err != nil {
+		return errors.Join(newErrUnmarshal(j), err)
+	}
+	if sh.Exporter == nil {
+		return newErrRequired(j, "exporter")
+	}
+	// Hydrate the exporter into the underlying field.
+	if err := json.Unmarshal(sh.Exporter, &sh.Plain.Exporter); err != nil {
+		return err
+	}
+	*j = PullMetricReader(sh.Plain)
+	return nil
+}

otelconf/config_test.go

@@ -1418,3 +1418,44 @@ func TestUnmarshalExporterDefaultHistogramAggregation(t *testing.T) {
 		})
 	}
 }
+
+func TestUnmarshalPullMetricReader(t *testing.T) {
+	for _, tt := range []struct {
+		name         string
+		yamlConfig   []byte
+		jsonConfig   []byte
+		wantErrT     error
+		wantExporter PullMetricExporter
+	}{
+		{
+			name:         "valid with proemtheus exporter",
+			jsonConfig:   []byte(`{"exporter":{"prometheus/development":{}}}`),
+			yamlConfig:   []byte("exporter:\n  prometheus/development: {}"),
+			wantExporter: PullMetricExporter{PrometheusDevelopment: &ExperimentalPrometheusMetricExporter{}},
+		},
+		{
+			name:       "missing required exporter field",
+			jsonConfig: []byte(`{}`),
+			yamlConfig: []byte("{}"),
+			wantErrT:   newErrRequired(&PullMetricReader{}, "exporter"),
+		},
+		{
+			name:       "invalid data",
+			jsonConfig: []byte(`{:2000}`),
+			yamlConfig: []byte("exporter:\n  prometheus/development: []"),
+			wantErrT:   newErrUnmarshal(&PullMetricReader{}),
+		},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			cl := PullMetricReader{}
+			err := cl.UnmarshalJSON(tt.jsonConfig)
+			assert.ErrorIs(t, err, tt.wantErrT)
+			assert.Equal(t, tt.wantExporter, cl.Exporter)
+
+			cl = PullMetricReader{}
+			err = yaml.Unmarshal(tt.yamlConfig, &cl)
+			assert.ErrorIs(t, err, tt.wantErrT)
+			assert.Equal(t, tt.wantExporter, cl.Exporter)
+		})
+	}
+}

otelconf/config_yaml.go

@@ -429,3 +429,17 @@ func (j *ExporterDefaultHistogramAggregation) UnmarshalYAML(node *yaml.Node) err
 	*j = ExporterDefaultHistogramAggregation(plain)
 	return nil
 }
+
+// UnmarshalYAML implements yaml.Unmarshaler.
+func (j *PullMetricReader) UnmarshalYAML(node *yaml.Node) error {
+	if !hasYAMLMapKey(node, "exporter") {
+		return newErrRequired(j, "exporter")
+	}
+	type Plain PullMetricReader
+	var plain Plain
+	if err := node.Decode(&plain); err != nil {
+		return errors.Join(newErrUnmarshal(j), err)
+	}
+	*j = PullMetricReader(plain)
+	return nil
+}