Create awscloudwatchmetricstreamsencodingextension

Create the component skeleton and basic config tests.
Unmarshallers will be implemented in a follow up PR.

Author: axw

.github/ISSUE_TEMPLATE/bug_report.yaml

@@ -96,6 +96,7 @@ body:
       - extension/cgroupruntime
       - extension/encoding
       - extension/encoding/avrologencoding
+      - extension/encoding/awscloudwatchmetricstreamsencoding
       - extension/encoding/googlecloudlogentryencoding
       - extension/encoding/jaegerencoding
       - extension/encoding/jsonlogencoding

.github/ISSUE_TEMPLATE/feature_request.yaml

@@ -90,6 +90,7 @@ body:
       - extension/cgroupruntime
       - extension/encoding
       - extension/encoding/avrologencoding
+      - extension/encoding/awscloudwatchmetricstreamsencoding
       - extension/encoding/googlecloudlogentryencoding
       - extension/encoding/jaegerencoding
       - extension/encoding/jsonlogencoding

.github/ISSUE_TEMPLATE/other.yaml

@@ -90,6 +90,7 @@ body:
       - extension/cgroupruntime
       - extension/encoding
       - extension/encoding/avrologencoding
+      - extension/encoding/awscloudwatchmetricstreamsencoding
       - extension/encoding/googlecloudlogentryencoding
       - extension/encoding/jaegerencoding
       - extension/encoding/jsonlogencoding

.github/ISSUE_TEMPLATE/unmaintained.yaml

@@ -95,6 +95,7 @@ body:
       - extension/cgroupruntime
       - extension/encoding
       - extension/encoding/avrologencoding
+      - extension/encoding/awscloudwatchmetricstreamsencoding
       - extension/encoding/googlecloudlogentryencoding
       - extension/encoding/jaegerencoding
       - extension/encoding/jsonlogencoding

extension/encoding/awscloudwatchmetricstreamsencodingextension/Makefile

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

extension/encoding/awscloudwatchmetricstreamsencodingextension/README.md

@@ -0,0 +1,32 @@
+# AWS CloudWatch Metric streams encoding extension
+
+<!-- status autogenerated section -->
+| Status        |           |
+| ------------- |-----------|
+| Stability     | [development]  |
+| Distributions | [] |
+| Issues        | [![Open issues](https://img.shields.io/github/issues-search/open-telemetry/opentelemetry-collector-contrib?query=is%3Aissue%20is%3Aopen%20label%3Aextension%2Fawscloudwatchmetricstreamsencoding%20&label=open&color=orange&logo=opentelemetry)](https://github.com/open-telemetry/opentelemetry-collector-contrib/issues?q=is%3Aopen+is%3Aissue+label%3Aextension%2Fawscloudwatchmetricstreamsencoding) [![Closed issues](https://img.shields.io/github/issues-search/open-telemetry/opentelemetry-collector-contrib?query=is%3Aissue%20is%3Aclosed%20label%3Aextension%2Fawscloudwatchmetricstreamsencoding%20&label=closed&color=blue&logo=opentelemetry)](https://github.com/open-telemetry/opentelemetry-collector-contrib/issues?q=is%3Aclosed+is%3Aissue+label%3Aextension%2Fawscloudwatchmetricstreamsencoding) |
+| [Code Owners](https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/main/CONTRIBUTING.md#becoming-a-code-owner)    | [@axw](https://www.github.com/axw) |
+
+[development]: https://github.com/open-telemetry/opentelemetry-collector/blob/main/docs/component-stability.md#development
+<!-- end autogenerated section -->
+
+This extension unmarshals metrics encoded in formats produced by
+[Amazon CloudWatch Metric Streams](https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/CloudWatch-Metric-Streams.html).
+
+The extension can be configured to unmarshal metrics in either the JSON or OpenTelemetry 1.0.0 output formats.
+At this time the OpenTelemetry 0.7.0 output format is unsupported, there are no plans to add support for it.
+
+Example for OpenTelemetry 1.0.0 format:
+```yaml
+extensions:
+  awscloudwatchmetricstreams_encoding:
+    format: opentelemetry1.0
+```
+
+Example for JSON format:
+```yaml
+extensions:
+  awscloudwatchmetricstreams_encoding:
+    format: json
+```

extension/encoding/awscloudwatchmetricstreamsencodingextension/config.go

@@ -0,0 +1,39 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package awscloudwatchmetricstreamsencodingextension // import "github.com/open-telemetry/opentelemetry-collector-contrib/extension/encoding/awscloudwatchmetricstreamsencodingextension"
+import (
+	"fmt"
+
+	"go.opentelemetry.io/collector/confmap/xconfmap"
+)
+
+var _ xconfmap.Validator = (*Config)(nil)
+
+const (
+	formatJSON            = "json"
+	formatOpenTelemetry10 = "opentelemetry1.0"
+)
+
+var supportedFormats = []string{formatOpenTelemetry10, formatJSON}
+
+type Config struct {
+	// Format defines the CloudWatch Metric Streams format.
+	//
+	// Valid values are "json" and "opentelemetry1.0"; opentelemetry0.7 is unsupported.
+	//
+	// See https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-cloudwatch-metricstream.html#cfn-cloudwatch-metricstream-outputformat
+	Format string `mapstructure:"format"`
+}
+
+func (cfg *Config) Validate() error {
+	switch cfg.Format {
+	case "":
+		return fmt.Errorf("format unspecified, expected one of %q", supportedFormats)
+	case formatJSON, formatOpenTelemetry10:
+		// valid
+	default:
+		return fmt.Errorf("unsupported format %q, expected one of %q", cfg.Format, supportedFormats)
+	}
+	return nil
+}

extension/encoding/awscloudwatchmetricstreamsencodingextension/config_test.go

@@ -0,0 +1,73 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package awscloudwatchmetricstreamsencodingextension
+
+import (
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/confmap/confmaptest"
+	"go.opentelemetry.io/collector/confmap/xconfmap"
+
+	"github.com/open-telemetry/opentelemetry-collector-contrib/extension/encoding/awscloudwatchmetricstreamsencodingextension/internal/metadata"
+)
+
+func TestLoadConfig(t *testing.T) {
+	t.Parallel()
+
+	cm, err := confmaptest.LoadConf(filepath.Join("testdata", "config.yaml"))
+	require.NoError(t, err)
+
+	tests := []struct {
+		id          component.ID
+		expected    component.Config
+		expectedErr string
+	}{
+		{
+			id:          component.NewIDWithName(metadata.Type, ""),
+			expectedErr: `format unspecified, expected one of ["opentelemetry1.0" "json"]`,
+		},
+		{
+			id: component.NewIDWithName(metadata.Type, "json"),
+			expected: &Config{
+				Format: formatJSON,
+			},
+		},
+		{
+			id: component.NewIDWithName(metadata.Type, "opentelemetry1.0"),
+			expected: &Config{
+				Format: formatOpenTelemetry10,
+			},
+		},
+		{
+			id:          component.NewIDWithName(metadata.Type, "opentelemetry0.7"),
+			expectedErr: `unsupported format "opentelemetry0.7", expected one of ["opentelemetry1.0" "json"]`,
+		},
+	}
+
+	for _, tt := range tests {
+		name := strings.ReplaceAll(tt.id.String(), "/", "_")
+		t.Run(name, func(t *testing.T) {
+			factory := NewFactory()
+			cfg := factory.CreateDefaultConfig()
+
+			sub, err := cm.Sub(tt.id.String())
+			require.NoError(t, err)
+			require.NoError(t, sub.Unmarshal(cfg))
+
+			err = xconfmap.Validate(cfg)
+			if tt.expectedErr != "" {
+				assert.Error(t, err)
+				assert.EqualError(t, err, tt.expectedErr)
+			} else {
+				assert.NoError(t, err)
+				assert.Equal(t, tt.expected, cfg)
+			}
+		})
+	}
+}

extension/encoding/awscloudwatchmetricstreamsencodingextension/doc.go

@@ -0,0 +1,8 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+//go:generate mdatagen metadata.yaml
+
+// Package awscloudwatchmetricstreamsencodingextension provides an encoding extension
+// capable of unmarshalling metrics produced by CloudWatch Metric Streams.
+package awscloudwatchmetricstreamsencodingextension // import "github.com/open-telemetry/opentelemetry-collector-contrib/extension/encoding/awscloudwatchmetricstreamsencodingextension"

extension/encoding/awscloudwatchmetricstreamsencodingextension/extension.go

@@ -0,0 +1,56 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package awscloudwatchmetricstreamsencodingextension // import "github.com/open-telemetry/opentelemetry-collector-contrib/extension/encoding/awscloudwatchmetricstreamsencodingextension"
+
+import (
+	"context"
+	"fmt"
+
+	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/pdata/pmetric"
+
+	"github.com/open-telemetry/opentelemetry-collector-contrib/extension/encoding"
+)
+
+var _ encoding.MetricsUnmarshalerExtension = (*encodingExtension)(nil)
+
+type encodingExtension struct {
+	pmetric.Unmarshaler
+}
+
+func newExtension(cfg *Config) (*encodingExtension, error) {
+	switch cfg.Format {
+	case formatJSON:
+		return &encodingExtension{Unmarshaler: formatJSONUnmarshaler{}}, nil
+	case formatOpenTelemetry10:
+		return &encodingExtension{Unmarshaler: formatOpenTelemetry10Unmarshaler{}}, nil
+	default:
+		// Format will have been validated by Config.Validate,
+		// so we'll only get here if we haven't handled a valid
+		// format.
+		return nil, fmt.Errorf("unimplemented format %q", cfg.Format)
+	}
+}
+
+func (*encodingExtension) Start(_ context.Context, _ component.Host) error {
+	return nil
+}
+
+func (*encodingExtension) Shutdown(_ context.Context) error {
+	return nil
+}
+
+type formatJSONUnmarshaler struct{}
+
+func (formatJSONUnmarshaler) UnmarshalMetrics([]byte) (pmetric.Metrics, error) {
+	// TODO implement
+	return pmetric.Metrics{}, fmt.Errorf("UnmarshalMetrics unimplemented for format %q", formatJSON)
+}
+
+type formatOpenTelemetry10Unmarshaler struct{}
+
+func (formatOpenTelemetry10Unmarshaler) UnmarshalMetrics([]byte) (pmetric.Metrics, error) {
+	// TODO implement
+	return pmetric.Metrics{}, fmt.Errorf("UnmarshalMetrics unimplemented for format %q", formatOpenTelemetry10)
+}