Begin implementation of OTLP/HTTP exporter

This adds the initial config and factory boilerplate and corresponding tests.

Contributes to: open-telemetry#882

Testing: config and factory tests unit tests added.

Documentation: Added README.

The next PR will add the exporting logic.

exporter/otlphttpexporter/README.md

@@ -0,0 +1,35 @@
+# OTLP/HTTP Exporter
+
+Exports traces and/or metrics via HTTP using
+[OTLP](https://github.com/open-telemetry/opentelemetry-specification/blob/master/specification/protocol/otlp.md) format.
+
+The following settings are required:
+
+- `endpoint` (no default): The target URL to send data to (e.g.: https://example.com:55681/v1/traces).
+
+The following settings can be optionally configured:
+
+- `insecure` (default = false): when set to true disables verifying the server's
+  certificate chain and host name. The connection is still encrypted but server identity
+  is not verified.
+- `ca_file` path to the CA cert. For a client this verifies the server certificate. Should
+  only be used if `insecure` is set to false.
+- `cert_file` path to the TLS cert to use for TLS required connections. Should
+  only be used if `insecure` is set to false.
+- `key_file` path to the TLS key to use for TLS required connections. Should
+  only be used if `insecure` is set to false.
+- `timeout` (default = 30s): How long to wait until the connection is close.
+- `read_buffer_size` (default = 0): ReadBufferSize for HTTP client.
+- `write_buffer_size` (default = 512 * 1024): WriteBufferSize for HTTP client.
+
+
+Example:
+
+```yaml
+exporters:
+  otlphttp:
+    endpoint: https://example.com:55681/v1/traces
+```
+
+The full list of settings exposed for this exporter are documented [here](./config.go)
+with detailed sample configurations [here](./testdata/config.yaml).

exporter/otlphttpexporter/config.go

@@ -0,0 +1,29 @@
+// 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 otlphttpexporter
+
+import (
+	"go.opentelemetry.io/collector/config/confighttp"
+	"go.opentelemetry.io/collector/config/configmodels"
+	"go.opentelemetry.io/collector/exporter/exporterhelper"
+)
+
+// Config defines configuration for OTLP/HTTP exporter.
+type Config struct {
+	configmodels.ExporterSettings `mapstructure:",squash"` // squash ensures fields are correctly decoded in embedded struct.
+	confighttp.HTTPClientSettings `mapstructure:",squash"` // squash ensures fields are correctly decoded in embedded struct.
+	exporterhelper.QueueSettings  `mapstructure:"sending_queue"`
+	exporterhelper.RetrySettings  `mapstructure:"retry_on_failure"`
+}

exporter/otlphttpexporter/config_test.go

@@ -0,0 +1,85 @@
+// 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 otlphttpexporter
+
+import (
+	"path"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"go.opentelemetry.io/collector/component/componenttest"
+	"go.opentelemetry.io/collector/config/confighttp"
+	"go.opentelemetry.io/collector/config/configmodels"
+	"go.opentelemetry.io/collector/config/configtest"
+	"go.opentelemetry.io/collector/config/configtls"
+	"go.opentelemetry.io/collector/exporter/exporterhelper"
+)
+
+func TestLoadConfig(t *testing.T) {
+	factories, err := componenttest.ExampleComponents()
+	assert.NoError(t, err)
+
+	factory := NewFactory()
+	factories.Exporters[typeStr] = factory
+	cfg, err := configtest.LoadConfigFile(t, path.Join(".", "testdata", "config.yaml"), factories)
+
+	require.NoError(t, err)
+	require.NotNil(t, cfg)
+
+	e0 := cfg.Exporters["otlphttp"]
+	assert.Equal(t, e0, factory.CreateDefaultConfig())
+
+	e1 := cfg.Exporters["otlphttp/2"]
+	assert.Equal(t, e1,
+		&Config{
+			ExporterSettings: configmodels.ExporterSettings{
+				NameVal: "otlphttp/2",
+				TypeVal: "otlphttp",
+			},
+			RetrySettings: exporterhelper.RetrySettings{
+				Enabled:         true,
+				InitialInterval: 10 * time.Second,
+				MaxInterval:     1 * time.Minute,
+				MaxElapsedTime:  10 * time.Minute,
+			},
+			QueueSettings: exporterhelper.QueueSettings{
+				Enabled:      true,
+				NumConsumers: 2,
+				QueueSize:    10,
+			},
+			HTTPClientSettings: confighttp.HTTPClientSettings{
+				Headers: map[string]string{
+					"can you have a . here?": "F0000000-0000-0000-0000-000000000000",
+					"header1":                "234",
+					"another":                "somevalue",
+				},
+				Endpoint: "https://1.2.3.4:1234",
+				TLSSetting: configtls.TLSClientSetting{
+					TLSSetting: configtls.TLSSetting{
+						CAFile:   "/var/lib/mycert.pem",
+						CertFile: "certfile",
+						KeyFile:  "keyfile",
+					},
+					Insecure: true,
+				},
+				ReadBufferSize:  123,
+				WriteBufferSize: 345,
+				Timeout:         time.Second * 10,
+			},
+		})
+}

exporter/otlphttpexporter/factory.go

@@ -0,0 +1,135 @@
+// 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 otlphttpexporter
+
+import (
+	"context"
+	"time"
+
+	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/config/confighttp"
+	"go.opentelemetry.io/collector/config/configmodels"
+	"go.opentelemetry.io/collector/exporter/exporterhelper"
+)
+
+const (
+	// The value of "type" key in configuration.
+	typeStr = "otlphttp"
+)
+
+// NewFactory creates a factory for OTLP exporter.
+func NewFactory() component.ExporterFactory {
+	return exporterhelper.NewFactory(
+		typeStr,
+		createDefaultConfig,
+		exporterhelper.WithTraces(createTraceExporter),
+		exporterhelper.WithMetrics(createMetricsExporter),
+		exporterhelper.WithLogs(createLogsExporter))
+}
+
+func createDefaultConfig() configmodels.Exporter {
+	return &Config{
+		ExporterSettings: configmodels.ExporterSettings{
+			TypeVal: typeStr,
+			NameVal: typeStr,
+		},
+		RetrySettings: exporterhelper.CreateDefaultRetrySettings(),
+		QueueSettings: exporterhelper.CreateDefaultQueueSettings(),
+		HTTPClientSettings: confighttp.HTTPClientSettings{
+			Endpoint: "",
+			Timeout:  30 * time.Second,
+			Headers:  map[string]string{},
+			// We almost read 0 bytes, so no need to tune ReadBufferSize.
+			WriteBufferSize: 512 * 1024,
+		},
+	}
+}
+
+func createTraceExporter(
+	_ context.Context,
+	_ component.ExporterCreateParams,
+	cfg configmodels.Exporter,
+) (component.TraceExporter, error) {
+	oce, err := newExporter(cfg)
+	if err != nil {
+		return nil, err
+	}
+	oCfg := cfg.(*Config)
+	oexp, err := exporterhelper.NewTraceExporter(
+		cfg,
+		oce.pushTraceData,
+		// explicitly disable since we rely on http.Client timeout logic.
+		exporterhelper.WithTimeout(exporterhelper.TimeoutSettings{Timeout: 0}),
+		exporterhelper.WithRetry(oCfg.RetrySettings),
+		exporterhelper.WithQueue(oCfg.QueueSettings),
+		exporterhelper.WithShutdown(oce.shutdown))
+	if err != nil {
+		return nil, err
+	}
+
+	return oexp, nil
+}
+
+func createMetricsExporter(
+	_ context.Context,
+	_ component.ExporterCreateParams,
+	cfg configmodels.Exporter,
+) (component.MetricsExporter, error) {
+	oce, err := newExporter(cfg)
+	if err != nil {
+		return nil, err
+	}
+	oCfg := cfg.(*Config)
+	oexp, err := exporterhelper.NewMetricsExporter(
+		cfg,
+		oce.pushMetricsData,
+		// explicitly disable since we rely on http.Client timeout logic.
+		exporterhelper.WithTimeout(exporterhelper.TimeoutSettings{Timeout: 0}),
+		exporterhelper.WithRetry(oCfg.RetrySettings),
+		exporterhelper.WithQueue(oCfg.QueueSettings),
+		exporterhelper.WithShutdown(oce.shutdown),
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return oexp, nil
+}
+
+func createLogsExporter(
+	_ context.Context,
+	_ component.ExporterCreateParams,
+	cfg configmodels.Exporter,
+) (component.LogsExporter, error) {
+	oce, err := newExporter(cfg)
+	if err != nil {
+		return nil, err
+	}
+	oCfg := cfg.(*Config)
+	oexp, err := exporterhelper.NewLogsExporter(
+		cfg,
+		oce.pushLogData,
+		// explicitly disable since we rely on http.Client timeout logic.
+		exporterhelper.WithTimeout(exporterhelper.TimeoutSettings{Timeout: 0}),
+		exporterhelper.WithRetry(oCfg.RetrySettings),
+		exporterhelper.WithQueue(oCfg.QueueSettings),
+		exporterhelper.WithShutdown(oce.shutdown),
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return oexp, nil
+}