Add Datadog exporter overall structure

exporter/datadogexporter/Makefile

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+include ../../Makefile.Common

exporter/datadogexporter/README.md

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+# Datadog Exporter
+
+This exporter sends metric data to [Datadog](https://datadoghq.com).
+
+## Configuration
+
+The only required setting is a [Datadog API key](https://app.datadoghq.com/account/settings#api).
+ ```yaml
+datadog:
+  api:
+    key: "<API key>"
+    # site: datadoghq.eu for sending data to the Datadog EU site
+ ```
+
+The hostname, environment, service and version can be set in the configuration for unified service tagging.
+
+See the sample configuration file under the `example` folder for other available options.

exporter/datadogexporter/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 datadogexporter
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"strings"
+
+	"go.opentelemetry.io/collector/config/configmodels"
+	"go.opentelemetry.io/collector/config/confignet"
+)
+
+var (
+	errUnsetAPIKey = errors.New("the Datadog API key is unset")
+)
+
+// APIConfig defines the API configuration options
+type APIConfig struct {
+	// Key is the Datadog API key to associate your Agent's data with your organization.
+	// Create a new API key here: https://app.datadoghq.com/account/settings
+	Key string `mapstructure:"key"`
+
+	// Site is the site of the Datadog intake to send data to.
+	// The default value is "datadoghq.com".
+	Site string `mapstructure:"site"`
+}
+
+// GetCensoredKey returns the API key censored for logging purposes
+func (api *APIConfig) GetCensoredKey() string {
+	if len(api.Key) <= 5 {
+		return api.Key
+	}
+	return strings.Repeat("*", len(api.Key)-5) + api.Key[len(api.Key)-5:]
+}
+
+// MetricsConfig defines the metrics exporter specific configuration options
+type MetricsConfig struct {
+	// Namespace is the namespace under which the metrics are sent
+	// By default metrics are not namespaced
+	Namespace string `mapstructure:"namespace"`
+
+	// Buckets states whether to report buckets from distribution metrics
+	Buckets bool `mapstructure:"report_buckets"`
+
+	// TCPAddr.Endpoint is the host of the Datadog intake server to send metrics to.
+	// If unset, the value is obtained from the Site.
+	confignet.TCPAddr `mapstructure:",squash"`
+}
+
+// TagsConfig defines the tag-related configuration
+// It is embedded in the configuration
+type TagsConfig struct {
+	// Hostname is the host name for unified service tagging.
+	// If unset, it is determined automatically.
+	// See https://docs.datadoghq.com/agent/faq/how-datadog-agent-determines-the-hostname
+	// for more details.
+	Hostname string `mapstructure:"hostname"`
+
+	// Env is the environment for unified service tagging.
+	// It can also be set through the `DD_ENV` environment variable.
+	Env string `mapstructure:"env"`
+
+	// Service is the service for unified service tagging.
+	// It can also be set through the `DD_SERVICE` environment variable.
+	Service string `mapstructure:"service"`
+
+	// Version is the version for unified service tagging.
+	// It can also be set through the `DD_VERSION` version variable.
+	Version string `mapstructure:"version"`
+
+	// Tags is the list of default tags to add to every metric or trace.
+	Tags []string `mapstructure:"tags"`
+}
+
+// UpdateWithEnv gets the unified service tagging information
+// from the environment variables.
+func (t *TagsConfig) UpdateWithEnv() {
+	if t.Hostname == "" {
+		t.Hostname = os.Getenv("DD_HOST")
+	}
+
+	if t.Env == "" {
+		t.Env = os.Getenv("DD_ENV")
+	}
+
+	if t.Service == "" {
+		t.Service = os.Getenv("DD_SERVICE")
+	}
+
+	if t.Version == "" {
+		t.Version = os.Getenv("DD_VERSION")
+	}
+}
+
+// GetTags gets the default tags extracted from the configuration
+func (t *TagsConfig) GetTags(addHost bool) []string {
+	tags := make([]string, 0, 4)
+
+	vars := map[string]string{
+		"env":     t.Env,
+		"service": t.Service,
+		"version": t.Version,
+	}
+
+	if addHost {
+		vars["host"] = t.Hostname
+	}
+
+	for name, val := range vars {
+		if val != "" {
+			tags = append(tags, fmt.Sprintf("%s:%s", name, val))
+		}
+	}
+
+	tags = append(tags, t.Tags...)
+
+	return tags
+}
+
+// Config defines configuration for the Datadog exporter.
+type Config struct {
+	configmodels.ExporterSettings `mapstructure:",squash"` // squash ensures fields are correctly decoded in embedded struct.
+
+	TagsConfig `mapstructure:",squash"`
+
+	// API defines the Datadog API configuration.
+	API APIConfig `mapstructure:"api"`
+
+	// Metrics defines the Metrics exporter specific configuration
+	Metrics MetricsConfig `mapstructure:"metrics"`
+}
+
+// Sanitize tries to sanitize a given configuration
+func (c *Config) Sanitize() error {
+	// Get info from environment variables
+	// if unset
+	c.TagsConfig.UpdateWithEnv()
+
+	// Add '.' at the end of namespace
+	if c.Metrics.Namespace != "" && !strings.HasSuffix(c.Metrics.Namespace, ".") {
+		c.Metrics.Namespace = c.Metrics.Namespace + "."
+	}
+
+	if c.API.Key == "" {
+		return errUnsetAPIKey
+	}
+
+	c.API.Key = strings.TrimSpace(c.API.Key)
+
+	// Set the endpoint based on the Site
+	if c.Metrics.TCPAddr.Endpoint == "" {
+		c.Metrics.TCPAddr.Endpoint = fmt.Sprintf("https://api.%s", c.API.Site)
+	}
+
+	return nil
+}

exporter/datadogexporter/config_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 datadogexporter
+
+import (
+	"os"
+	"path"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.opentelemetry.io/collector/component/componenttest"
+	"go.opentelemetry.io/collector/config/configmodels"
+	"go.opentelemetry.io/collector/config/confignet"
+	"go.opentelemetry.io/collector/config/configtest"
+)
+
+// TestLoadConfig tests that the configuration is loaded correctly
+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)
+
+	apiConfig := cfg.Exporters["datadog/api"].(*Config)
+	err = apiConfig.Sanitize()
+
+	require.NoError(t, err)
+	assert.Equal(t, &Config{
+		ExporterSettings: configmodels.ExporterSettings{
+			NameVal: "datadog/api",
+			TypeVal: typeStr,
+		},
+
+		TagsConfig: TagsConfig{
+			Hostname: "customhostname",
+			Env:      "prod",
+			Service:  "myservice",
+			Version:  "myversion",
+			Tags:     []string{"example:tag"},
+		},
+
+		API: APIConfig{
+			Key:  "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
+			Site: "datadoghq.eu",
+		},
+
+		Metrics: MetricsConfig{
+			Namespace: "opentelemetry.",
+			TCPAddr: confignet.TCPAddr{
+				Endpoint: "https://api.datadoghq.eu",
+			},
+		},
+	}, apiConfig)
+
+	invalidConfig2 := cfg.Exporters["datadog/invalid"].(*Config)
+	err = invalidConfig2.Sanitize()
+	require.Error(t, err)
+
+}
+
+func TestTags(t *testing.T) {
+	tc := TagsConfig{
+		Hostname: "customhost",
+		Env:      "customenv",
+		Service:  "customservice",
+		Version:  "customversion",
+		Tags:     []string{"key1:val1", "key2:val2"},
+	}
+
+	assert.ElementsMatch(t,
+		[]string{
+			"host:customhost",
+			"env:customenv",
+			"service:customservice",
+			"version:customversion",
+			"key1:val1",
+			"key2:val2",
+		},
+		tc.GetTags(true), // get host
+	)
+}
+
+// TestOverrideMetricsURL tests that the metrics URL is overridden
+// correctly when set manually.
+func TestOverrideMetricsURL(t *testing.T) {
+
+	const DebugEndpoint string = "http://localhost:8080"
+
+	cfg := Config{
+		API: APIConfig{Key: "notnull", Site: DefaultSite},
+		Metrics: MetricsConfig{
+			TCPAddr: confignet.TCPAddr{
+				Endpoint: DebugEndpoint,
+			},
+		},
+	}
+
+	err := cfg.Sanitize()
+	require.NoError(t, err)
+	assert.Equal(t, cfg.Metrics.Endpoint, DebugEndpoint)
+}
+
+func TestAPIKeyUnset(t *testing.T) {
+	cfg := Config{}
+	err := cfg.Sanitize()
+	assert.Equal(t, err, errUnsetAPIKey)
+}
+
+func TestCensorAPIKey(t *testing.T) {
+	cfg := APIConfig{
+		Key: "ddog_32_characters_long_api_key1",
+	}
+
+	assert.Equal(
+		t,
+		"***************************_key1",
+		cfg.GetCensoredKey(),
+	)
+}
+
+func TestUpdateWithEnv(t *testing.T) {
+	cfg := TagsConfig{
+		Hostname: "test_host",
+		Env:      "test_env",
+	}
+
+	// Should be ignored since they were set
+	// on config
+	os.Setenv("DD_HOST", "env_host")
+	os.Setenv("DD_ENV", "env_env")
+
+	// Should be picked up
+	os.Setenv("DD_SERVICE", "env_service")
+	os.Setenv("DD_VERSION", "env_version")
+
+	cfg.UpdateWithEnv()
+
+	assert.Equal(t,
+		TagsConfig{
+			Hostname: "test_host",
+			Env:      "test_env",
+			Service:  "env_service",
+			Version:  "env_version",
+		},
+		cfg,
+	)
+}