Create initial structure for Tanzu Observability exporter (#3393)

* Create initial structure for Tanzu Observability exporter

Signed-off-by: Peter Stone <[email protected]>

* remove accidental printf

Signed-off-by: Peter Stone <[email protected]>

* PR feedback: use confighttp helper

* PR feedback: remove config for attribute transformation

* PR feedback: update README to match config changes

Signed-off-by: Glenn Oppegard <[email protected]>

Co-authored-by: Glenn Oppegard <[email protected]>

exporter/tanzuobservabilityexporter/Makefile

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+include ../../Makefile.Common

exporter/tanzuobservabilityexporter/README.md

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+# Tanzu Observability (Wavefront) Exporter
+
+This exporter supports sending traces to [Tanzu Observability](https://tanzu.vmware.com/observability).
+
+## Prerequisites
+
+- [Obtain the Tanzu Observability by Wavefront API token.](https://docs.wavefront.com/wavefront_api.html#generating-an-api-token)
+- [Set up and start a Tanzu Observability by Wavefront proxy](https://docs.wavefront.com/proxies_installing.html) and configure it with the API token you obtained.
+- To have the proxy generate [span RED metrics](https://docs.wavefront.com/trace_data_details.html#red-metrics) from trace data, [configure](https://docs.wavefront.com/proxies_configuring.html) the proxy's `customTracingListenerPorts` and use it for the exporter's endpoint.
+
+## Data Conversion
+
+- Trace IDs and Span IDs are converted to UUIDs. For example, span IDs are left-padded with zeros to fit the correct size.
+- Events are converted to [Span Logs](https://docs.wavefront.com/trace_data_details.html#span-logs).
+- Kind is converted to the `span.kind` tag.
+- Status is converted to `error`, `status.code` and `status.message` tags.
+- TraceState is converted to the `w3c.tracestate` tag.
+
+## Tanzu Observability Specific Attributes
+
+- Application identity tags, which are [required by Tanzu Observability](https://docs.wavefront.com/trace_data_details.html#how-wavefront-uses-application-tags), are added if they are missing.
+    - `application` is set to "defaultApp".
+    - `service` is set to "defaultService".
+
+## Exporter Configuration
+
+```yaml
+receivers:
+  examplereceiver:
+
+processors:
+  batch:
+    timeout: 10s
+
+exporters:
+  tanzuobservability:
+    traces:
+      # Hostname and `customTracingListenerPorts` of the Wavefront Proxy
+      endpoint: "http://localhost:30001"
+
+service:
+  pipelines:
+    traces:
+      receivers: [examplereceiver]
+      processors: [batch]
+      exporters: [tanzuobservability]
+```

exporter/tanzuobservabilityexporter/config.go

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+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package tanzuobservabilityexporter
+
+import (
+	"fmt"
+
+	"go.opentelemetry.io/collector/config"
+	"go.opentelemetry.io/collector/config/confighttp"
+)
+
+type TracesConfig struct {
+	confighttp.HTTPClientSettings `mapstructure:",squash"` // squash ensures fields are correctly decoded in embedded struct.
+}
+
+// Config defines configuration options for the exporter.
+type Config struct {
+	config.ExporterSettings `mapstructure:",squash"` // squash ensures fields are correctly decoded in embedded struct.
+
+	// Traces defines the Traces exporter specific configuration
+	Traces TracesConfig `mapstructure:"traces"`
+}
+
+func (c *Config) Validate() error {
+	if c.Traces.Endpoint == "" {
+		return fmt.Errorf("A non-empty traces.endpoint is required")
+	}
+	return nil
+}

exporter/tanzuobservabilityexporter/config_test.go

@@ -0,0 +1,34 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package tanzuobservabilityexporter
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"go.opentelemetry.io/collector/config"
+	"go.opentelemetry.io/collector/config/confighttp"
+)
+
+func TestConfigRequiresNonEmptyEndpoint(t *testing.T) {
+	c := &Config{
+		ExporterSettings: config.ExporterSettings{},
+		Traces: TracesConfig{
+			HTTPClientSettings: confighttp.HTTPClientSettings{Endpoint: ""},
+		},
+	}
+
+	require.Error(t, c.Validate())
+}

exporter/tanzuobservabilityexporter/factory.go

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+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package tanzuobservabilityexporter
+
+import (
+	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/config"
+	"go.opentelemetry.io/collector/config/confighttp"
+	"go.opentelemetry.io/collector/exporter/exporterhelper"
+)
+
+const exporterType = "tanzuobservability"
+
+// NewFactory creates a factory for the exporter.
+func NewFactory() component.ExporterFactory {
+	return exporterhelper.NewFactory(
+		exporterType,
+		createDefaultConfig,
+		//exporterhelper.WithTraces(createTraceExporter),
+	)
+}
+
+func createDefaultConfig() config.Exporter {
+	tracesCfg := TracesConfig{
+		HTTPClientSettings: confighttp.HTTPClientSettings{Endpoint: "http://localhost:30001"},
+	}
+	return &Config{
+		ExporterSettings: config.NewExporterSettings(config.NewID(exporterType)),
+		Traces:           tracesCfg,
+	}
+}

exporter/tanzuobservabilityexporter/factory_test.go

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+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package tanzuobservabilityexporter
+
+import (
+	"path"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.opentelemetry.io/collector/component/componenttest"
+	"go.opentelemetry.io/collector/config"
+	"go.opentelemetry.io/collector/config/configcheck"
+	"go.opentelemetry.io/collector/config/confighttp"
+	"go.opentelemetry.io/collector/config/configtest"
+)
+
+func TestCreateDefaultConfig(t *testing.T) {
+	cfg := createDefaultConfig()
+	assert.NotNil(t, cfg, "failed to create default config")
+	require.NoError(t, configcheck.ValidateConfig(cfg))
+
+	actual, ok := cfg.(*Config)
+	require.True(t, ok, "invalid Config: %#v", cfg)
+	assert.Equal(t, "http://localhost:30001", actual.Traces.Endpoint)
+}
+
+func TestLoadConfig(t *testing.T) {
+	factories, err := componenttest.NopFactories()
+	assert.NoError(t, err)
+
+	factory := NewFactory()
+	// TODO come back to config.Type
+	factories.Exporters[config.Type(exporterType)] = factory
+	cfg, err := configtest.LoadConfigFile(t, path.Join(".", "testdata", "config.yaml"), factories)
+
+	require.NoError(t, err)
+	require.NotNil(t, cfg)
+
+	actual, ok := cfg.Exporters[config.NewID("tanzuobservability")]
+	require.True(t, ok)
+	expected := &Config{
+		ExporterSettings: config.NewExporterSettings(config.NewID("tanzuobservability")),
+		Traces: TracesConfig{
+			HTTPClientSettings: confighttp.HTTPClientSettings{Endpoint: "http://localhost:40001"},
+		},
+	}
+	assert.Equal(t, expected, actual)
+}

exporter/tanzuobservabilityexporter/go.mod

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+module github.com/open-telemetry/opentelemetry-collector-contrib/exporter/tanzuobservabilityexporter
+
+go 1.15
+
+require (
+	github.com/stretchr/testify v1.7.0
+	go.opentelemetry.io/collector v0.26.1-0.20210514011731-65a43fe39980
+	go.uber.org/zap v1.16.0
+)