[extension/awsmiddleware] Add AWS middleware extension interface (ama…

…zon-contributing#116)

.github/CODEOWNERS

@@ -89,6 +89,7 @@ exporter/tencentcloudlogserviceexporter/                 @open-telemetry/collect
 exporter/zipkinexporter/                                 @open-telemetry/collector-contrib-approvers @MovieStoreGuy @astencel-sumo @crobert-1
 
 extension/asapauthextension/                             @open-telemetry/collector-contrib-approvers @jamesmoessis @MovieStoreGuy
+extension/awsmiddleware									 @open-telemetry/collector-contrib-approvers @jefchien
 extension/awsproxy/                                      @open-telemetry/collector-contrib-approvers @Aneurysm9 @mxiamxia
 extension/basicauthextension/                            @open-telemetry/collector-contrib-approvers @jpkrohling @svrakitin @frzifus
 extension/bearertokenauthextension/                      @open-telemetry/collector-contrib-approvers @jpkrohling @pavankrish123 @frzifus

exporter/awsemfexporter/metric_translator_test.go

@@ -1456,22 +1456,22 @@ func TestGroupedMetricToCWMeasurementsWithFilters(t *testing.T) {
 					MetricNameSelectors: []string{"metric(1|3)"},
 				},
 			}, []cWMeasurement{
-			{
-				Namespace:  namespace,
-				Dimensions: [][]string{{}},
-				Metrics: []map[string]string{
-					{
-						"Name": "metric1",
-						"Unit": "Count",
-					},
-					{
-						"Name": "metric3",
-						"Unit": "Seconds",
+				{
+					Namespace:  namespace,
+					Dimensions: [][]string{{}},
+					Metrics: []map[string]string{
+						{
+							"Name": "metric1",
+							"Unit": "Count",
+						},
+						{
+							"Name": "metric3",
+							"Unit": "Seconds",
+						},
 					},
 				},
 			},
 		},
-		},
 		{
 			"label matchers",
 			[]*MetricDeclaration{

extension/awsmiddleware/Makefile

@@ -0,0 +1 @@
+include ../../Makefile.Common

extension/awsmiddleware/README.md

@@ -0,0 +1,29 @@
+# AWS Middleware
+
+An AWS middleware extension provides request and/or response handlers that can be configured on AWS SDK v1/v2 clients.
+Other components can configure their AWS SDK clients using the `awsmiddleware.ConfigureSDKv1` and `awsmiddleware.ConfigureSDKv2` functions.
+
+The `awsmiddleware.Extension` interface extends `component.Extension` by adding the following methods:
+```
+RequestHandlers() []RequestHandler
+ResponseHandlers() []ResponseHandler
+```
+
+The `awsmiddleware.RequestHandler` interface contains the following methods:
+```
+ID() string
+Position() HandlerPosition
+HandleRequest(r *http.Request)
+```
+
+The `awsmiddleware.ResponseHandler` interface contains the following methods:
+```
+ID() string
+Position() HandlerPosition
+HandleResponse(r *http.Response)
+```
+
+- `ID` uniquely identifies a handler. Middleware will fail if there is clashing 
+- `Position` determines whether the handler is appended to the front or back of the existing list. Insertion is done
+in the order of the handlers provided.
+- `HandleRequest/Response` provides a hook to handle the request/response before and after they've been sent.

extension/awsmiddleware/config.go

@@ -0,0 +1,27 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package awsmiddleware // import "github.com/open-telemetry/opentelemetry-collector-contrib/extension/awsmiddleware"
+
+import (
+	"fmt"
+
+	"go.opentelemetry.io/collector/component"
+)
+
+// Config defines the configuration for an AWS Middleware extension.
+type Config struct {
+	// MiddlewareID is the ID of the Middleware extension.
+	MiddlewareID component.ID `mapstructure:"middleware"`
+}
+
+// GetMiddleware retrieves the extension implementing Middleware based on the MiddlewareID.
+func (c Config) GetMiddleware(extensions map[component.ID]component.Component) (Middleware, error) {
+	if ext, found := extensions[c.MiddlewareID]; found {
+		if mw, ok := ext.(Middleware); ok {
+			return mw, nil
+		}
+		return nil, errNotMiddleware
+	}
+	return nil, fmt.Errorf("failed to resolve AWS client handler %q: %w", c.MiddlewareID, errNotFound)
+}

extension/awsmiddleware/config_test.go

@@ -0,0 +1,67 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package awsmiddleware
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/extension/extensiontest"
+)
+
+type testMiddlewareExtension struct {
+	component.StartFunc
+	component.ShutdownFunc
+	requestHandlers  []RequestHandler
+	responseHandlers []ResponseHandler
+}
+
+var _ Extension = (*testMiddlewareExtension)(nil)
+
+func (t *testMiddlewareExtension) RequestHandlers() []RequestHandler {
+	return t.requestHandlers
+}
+
+func (t *testMiddlewareExtension) ResponseHandlers() []ResponseHandler {
+	return t.responseHandlers
+}
+
+func TestGetMiddleware(t *testing.T) {
+	id := component.NewID("test")
+	cfg := &Config{MiddlewareID: id}
+	nopExtension, err := extensiontest.NewNopBuilder().Create(context.Background(), extensiontest.NewNopCreateSettings())
+	require.Error(t, err)
+	testCases := map[string]struct {
+		extensions map[component.ID]component.Component
+		wantErr    error
+	}{
+		"WithNoExtensions": {
+			extensions: map[component.ID]component.Component{},
+			wantErr:    errNotFound,
+		},
+		"WithNonMiddlewareExtension": {
+			extensions: map[component.ID]component.Component{id: nopExtension},
+			wantErr:    errNotMiddleware,
+		},
+		"WithMiddlewareExtension": {
+			extensions: map[component.ID]component.Component{id: &testMiddlewareExtension{}},
+		},
+	}
+	for name, testCase := range testCases {
+		t.Run(name, func(t *testing.T) {
+			got, err := cfg.GetMiddleware(testCase.extensions)
+			if testCase.wantErr != nil {
+				assert.Error(t, err)
+				assert.ErrorIs(t, err, testCase.wantErr)
+				assert.Nil(t, got)
+			} else {
+				assert.NoError(t, err)
+				assert.NotNil(t, got)
+			}
+		})
+	}
+}

extension/awsmiddleware/doc.go

@@ -0,0 +1,6 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+// Package awsmiddleware defines an extension interface providing request and response handlers that can be
+// configured on AWS SDK clients.
+package awsmiddleware // import "github.com/open-telemetry/opentelemetry-collector-contrib/extension/awsmiddleware"

extension/awsmiddleware/go.mod

@@ -0,0 +1,51 @@
+module github.com/open-telemetry/opentelemetry-collector-contrib/extension/awsmiddleware
+
+go 1.20
+
+require (
+	github.com/aws/aws-sdk-go v1.45.24
+	github.com/aws/aws-sdk-go-v2 v1.21.1
+	github.com/aws/aws-sdk-go-v2/service/s3 v1.40.0
+	github.com/aws/smithy-go v1.15.0
+	github.com/stretchr/testify v1.8.4
+	go.opentelemetry.io/collector/component v0.87.0
+	go.opentelemetry.io/collector/extension v0.87.0
+)
+
+require (
+	github.com/aws/aws-sdk-go-v2/aws/protocol/eventstream v1.4.13 // indirect
+	github.com/aws/aws-sdk-go-v2/internal/configsources v1.1.42 // indirect
+	github.com/aws/aws-sdk-go-v2/internal/endpoints/v2 v2.4.36 // indirect
+	github.com/aws/aws-sdk-go-v2/internal/v4a v1.1.4 // indirect
+	github.com/aws/aws-sdk-go-v2/service/internal/accept-encoding v1.9.14 // indirect
+	github.com/aws/aws-sdk-go-v2/service/internal/checksum v1.1.36 // indirect
+	github.com/aws/aws-sdk-go-v2/service/internal/presigned-url v1.9.36 // indirect
+	github.com/aws/aws-sdk-go-v2/service/internal/s3shared v1.15.4 // indirect
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/gogo/protobuf v1.3.2 // indirect
+	github.com/golang/protobuf v1.5.3 // indirect
+	github.com/jmespath/go-jmespath v0.4.0 // indirect
+	github.com/knadh/koanf/maps v0.1.1 // indirect
+	github.com/knadh/koanf/providers/confmap v0.1.0 // indirect
+	github.com/knadh/koanf/v2 v2.0.1 // indirect
+	github.com/mitchellh/copystructure v1.2.0 // indirect
+	github.com/mitchellh/mapstructure v1.5.1-0.20220423185008-bf980b35cac4 // indirect
+	github.com/mitchellh/reflectwalk v1.0.2 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	go.opentelemetry.io/collector/config/configtelemetry v0.87.0 // indirect
+	go.opentelemetry.io/collector/confmap v0.87.0 // indirect
+	go.opentelemetry.io/collector/featuregate v1.0.0-rcv0016 // indirect
+	go.opentelemetry.io/collector/pdata v1.0.0-rcv0016 // indirect
+	go.opentelemetry.io/otel v1.19.0 // indirect
+	go.opentelemetry.io/otel/metric v1.19.0 // indirect
+	go.opentelemetry.io/otel/trace v1.19.0 // indirect
+	go.uber.org/multierr v1.11.0 // indirect
+	go.uber.org/zap v1.26.0 // indirect
+	golang.org/x/net v0.15.0 // indirect
+	golang.org/x/sys v0.12.0 // indirect
+	golang.org/x/text v0.13.0 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20230711160842-782d3b101e98 // indirect
+	google.golang.org/grpc v1.58.2 // indirect
+	google.golang.org/protobuf v1.31.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)