Add support for Resources in the SDK

api/metric/api.go

@@ -21,6 +21,7 @@ import (
 
 	"go.opentelemetry.io/otel/api/core"
 	"go.opentelemetry.io/otel/api/unit"
+	"go.opentelemetry.io/otel/sdk/resource"
 )
 
 // Provider supports named Meter instances.
@@ -45,6 +46,8 @@ type Config struct {
 	// Keys are recommended keys determined in the handles
 	// obtained for the metric.
 	Keys []core.Key
+	// Resource describes the entity for which measurements are made.
+	Resource resource.Resource
 }
 
 // Option is an interface for applying metric options.
@@ -141,6 +144,12 @@ func (d Descriptor) NumberKind() core.NumberKind {
 	return d.numberKind
 }
 
+// Resource returns the Resource describing the entity for which the metric
+// instrument measures.
+func (d Descriptor) Resource() resource.Resource {
+	return d.config.Resource
+}
+
 // Meter is an interface to the metrics portion of the OpenTelemetry SDK.
 type Meter interface {
 	// Labels returns a reference to a set of labels that cannot
@@ -212,3 +221,16 @@ type keysOption []core.Key
 func (k keysOption) Apply(config *Config) {
 	config.Keys = append(config.Keys, k...)
 }
+
+// WithResource applies provided Resource.
+//
+// This will override any existing Resource.
+func WithResource(r resource.Resource) Option {
+	return resourceOption(r)
+}
+
+type resourceOption resource.Resource
+
+func (r resourceOption) Apply(config *Config) {
+	config.Resource = resource.Resource(r)
+}

api/metric/api_test.go

@@ -25,6 +25,7 @@ import (
 	"go.opentelemetry.io/otel/api/metric"
 	"go.opentelemetry.io/otel/api/unit"
 	mockTest "go.opentelemetry.io/otel/internal/metric"
+	"go.opentelemetry.io/otel/sdk/resource"
 
 	"github.com/google/go-cmp/cmp"
 	"github.com/stretchr/testify/assert"
@@ -35,19 +36,21 @@ var Must = metric.Must
 
 func TestOptions(t *testing.T) {
 	type testcase struct {
-		name string
-		opts []metric.Option
-		keys []core.Key
-		desc string
-		unit unit.Unit
+		name     string
+		opts     []metric.Option
+		keys     []core.Key
+		desc     string
+		unit     unit.Unit
+		resource resource.Resource
 	}
 	testcases := []testcase{
 		{
-			name: "no opts",
-			opts: nil,
-			keys: nil,
-			desc: "",
-			unit: "",
+			name:     "no opts",
+			opts:     nil,
+			keys:     nil,
+			desc:     "",
+			unit:     "",
+			resource: resource.Resource{},
 		},
 		{
 			name: "keys keys keys",
@@ -61,46 +64,61 @@ func TestOptions(t *testing.T) {
 				key.New("bar"), key.New("bar2"),
 				key.New("baz"), key.New("baz2"),
 			},
-			desc: "",
-			unit: "",
+			desc:     "",
+			unit:     "",
+			resource: resource.Resource{},
 		},
 		{
 			name: "description",
 			opts: []metric.Option{
 				metric.WithDescription("stuff"),
 			},
-			keys: nil,
-			desc: "stuff",
-			unit: "",
+			keys:     nil,
+			desc:     "stuff",
+			unit:     "",
+			resource: resource.Resource{},
 		},
 		{
 			name: "description override",
 			opts: []metric.Option{
 				metric.WithDescription("stuff"),
 				metric.WithDescription("things"),
 			},
-			keys: nil,
-			desc: "things",
-			unit: "",
+			keys:     nil,
+			desc:     "things",
+			unit:     "",
+			resource: resource.Resource{},
 		},
 		{
 			name: "unit",
 			opts: []metric.Option{
 				metric.WithUnit("s"),
 			},
-			keys: nil,
-			desc: "",
-			unit: "s",
+			keys:     nil,
+			desc:     "",
+			unit:     "s",
+			resource: resource.Resource{},
 		},
 		{
 			name: "unit override",
 			opts: []metric.Option{
 				metric.WithUnit("s"),
 				metric.WithUnit("h"),
 			},
-			keys: nil,
-			desc: "",
-			unit: "h",
+			keys:     nil,
+			desc:     "",
+			unit:     "h",
+			resource: resource.Resource{},
+		},
+		{
+			name: "resource override",
+			opts: []metric.Option{
+				metric.WithResource(*resource.New(key.New("name").String("test-name"))),
+			},
+			keys:     nil,
+			desc:     "",
+			unit:     "",
+			resource: *resource.New(key.New("name").String("test-name")),
 		},
 	}
 	for idx, tt := range testcases {
@@ -109,6 +127,7 @@ func TestOptions(t *testing.T) {
 			Description: tt.desc,
 			Unit:        tt.unit,
 			Keys:        tt.keys,
+			Resource:    tt.resource,
 		}); diff != "" {
 			t.Errorf("Compare options: -got +want %s", diff)
 		}

api/metric/sdkhelpers.go

@@ -18,6 +18,7 @@ import (
 	"context"
 
 	"go.opentelemetry.io/otel/api/core"
+	"go.opentelemetry.io/otel/sdk/resource"
 )
 
 // MeterImpl is a convenient interface for SDK and test
@@ -133,6 +134,29 @@ func Configure(opts []Option) Config {
 	return config
 }
 
+// Resourcer is implemented by any value that has a Resource method,
+// which returns the Resource associated with the value.
+// The Resource method is used to set the Resource for Descriptors of new
+// metric instruments.
+type Resourcer interface {
+	Resource() resource.Resource
+}
+
+// insertResource inserts a WithResource option at the beginning of opts
+// using the resource defined by impl if impl implements Resourcer.
+//
+// If opts contains a WithResource option already, that Option will take
+// precedence and overwrite the Resource set from impl.
+//
+// The returned []Option may uses the same underlying array as opts.
+func insertResource(impl MeterImpl, opts []Option) []Option {
+	if r, ok := impl.(Resourcer); ok {
+		// default to the impl resource and override if passed in opts.
+		return append([]Option{WithResource(r.Resource())}, opts...)
+	}
+	return opts
+}
+
 // WrapMeterImpl constructs a `Meter` implementation from a
 // `MeterImpl` implementation.
 func WrapMeterImpl(impl MeterImpl) Meter {
@@ -159,6 +183,7 @@ func (m *wrappedMeterImpl) RecordBatch(ctx context.Context, ls LabelSet, ms ...M
 }
 
 func (m *wrappedMeterImpl) newSync(name string, metricKind Kind, numberKind core.NumberKind, opts []Option) (SyncImpl, error) {
+	opts = insertResource(m.impl, opts)
 	return m.impl.NewSyncInstrument(NewDescriptor(name, metricKind, numberKind, opts...))
 }
 
@@ -219,6 +244,7 @@ func WrapFloat64MeasureInstrument(syncInst SyncImpl, err error) (Float64Measure,
 }
 
 func (m *wrappedMeterImpl) newAsync(name string, mkind Kind, nkind core.NumberKind, opts []Option, callback func(func(core.Number, LabelSet))) (AsyncImpl, error) {
+	opts = insertResource(m.impl, opts)
 	return m.impl.NewAsyncInstrument(
 		NewDescriptor(name, mkind, nkind, opts...),
 		callback)

sdk/export/metric/metric.go

@@ -1,4 +1,4 @@
-// Copyright 2019, OpenTelemetry Authors
+// Copyright 2020, OpenTelemetry Authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.

sdk/metric/config.go

@@ -0,0 +1,44 @@
+package metric
+
+import "go.opentelemetry.io/otel/sdk/resource"
+
+// Config contains configuration for an SDK.
+type Config struct {
+	// ErrorHandler is the function called when the SDK encounters an error.
+	//
+	// This option can be overridden after instantiation of the SDK
+	// with the `SetErrorHandler` method.
+	ErrorHandler ErrorHandler
+
+	// Resource is the OpenTelemetry resource associated with all Meters
+	// created by the SDK.
+	Resource resource.Resource
+}
+
+// Option is the interface that applies the value to a configuration option.
+type Option interface {
+	// Apply sets the Option value of a Config.
+	Apply(*Config)
+}
+
+// WithErrorHandler sets the ErrorHandler configuration option of a Config.
+func WithErrorHandler(fn ErrorHandler) Option {
+	return errorHandlerOption(fn)
+}
+
+type errorHandlerOption ErrorHandler
+
+func (o errorHandlerOption) Apply(config *Config) {
+	config.ErrorHandler = ErrorHandler(o)
+}
+
+// WithResource sets the Resource configuration option of a Config.
+func WithResource(r resource.Resource) Option {
+	return resourceOption(r)
+}
+
+type resourceOption resource.Resource
+
+func (o resourceOption) Apply(config *Config) {
+	config.Resource = resource.Resource(o)
+}

sdk/metric/config_test.go

@@ -0,0 +1,47 @@
+package metric
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"go.opentelemetry.io/otel/api/core"
+	"go.opentelemetry.io/otel/sdk/resource"
+)
+
+func TestWithErrorHandler(t *testing.T) {
+	errH, reg := func() (ErrorHandler, *error) {
+		e := fmt.Errorf("default invalid")
+		reg := &e
+		return func(err error) {
+			*reg = err
+		}, reg
+	}()
+
+	c := &Config{}
+	WithErrorHandler(errH).Apply(c)
+	err1 := fmt.Errorf("error 1")
+	c.ErrorHandler(err1)
+	assert.EqualError(t, *reg, err1.Error())
+
+	// Ensure overwriting works.
+	c = &Config{ErrorHandler: DefaultErrorHandler}
+	WithErrorHandler(errH).Apply(c)
+	err2 := fmt.Errorf("error 2")
+	c.ErrorHandler(err2)
+	assert.EqualError(t, *reg, err2.Error())
+}
+
+func TestWithResource(t *testing.T) {
+	r := resource.New(core.Key("A").String("a"))
+
+	c := &Config{}
+	WithResource(*r).Apply(c)
+	assert.Equal(t, *r, c.Resource)
+
+	// Ensure overwriting works.
+	c = &Config{Resource: resource.Resource{}}
+	WithResource(*r).Apply(c)
+	assert.Equal(t, *r, c.Resource)
+}

sdk/metric/controller/push/config.go

@@ -0,0 +1,47 @@
+package push
+
+import (
+	sdk "go.opentelemetry.io/otel/sdk/metric"
+	"go.opentelemetry.io/otel/sdk/resource"
+)
+
+// Config contains configuration for a push Controller.
+type Config struct {
+	// ErrorHandler is the function called when the Controller encounters an error.
+	//
+	// This option can be overridden after instantiation of the Controller
+	// with the `SetErrorHandler` method.
+	ErrorHandler sdk.ErrorHandler
+
+	// Resource is the OpenTelemetry resource associated with all Meters
+	// created by the Controller.
+	Resource resource.Resource
+}
+
+// Option is the interface that applies the value to a configuration option.
+type Option interface {
+	// Apply sets the Option value of a Config.
+	Apply(*Config)
+}
+
+// WithErrorHandler sets the ErrorHandler configuration option of a Config.
+func WithErrorHandler(fn sdk.ErrorHandler) Option {
+	return errorHandlerOption(fn)
+}
+
+type errorHandlerOption sdk.ErrorHandler
+
+func (o errorHandlerOption) Apply(config *Config) {
+	config.ErrorHandler = sdk.ErrorHandler(o)
+}
+
+// WithResource sets the Resource configuration option of a Config.
+func WithResource(r resource.Resource) Option {
+	return resourceOption(r)
+}
+
+type resourceOption resource.Resource
+
+func (o resourceOption) Apply(config *Config) {
+	config.Resource = resource.Resource(o)
+}