Refactor OTLP exporter env config to be shared across all exporters (#2608)

* setup global envconfig package for otlp exporter

* use envconfig in otlpmetrics package

* fix lint

* add changelog entry

* Update exporters/otlp/internal/envconfig/envconfig.go

Co-authored-by: Chester Cheung <cheung.zhy.csu@gmail.com>

* fix lint

Co-authored-by: Chester Cheung <cheung.zhy.csu@gmail.com>
Co-authored-by: Anthony Mirabella <a9@aneurysm9.com>

CHANGELOG.md

@@ -31,6 +31,7 @@ This update is a breaking change of the unstable Metrics API. Code instrumented
 - The metrics API has been significantly changed. (#2587)
 - Unify path cleaning functionally in the `otlpmetric` and `otlptrace` config. (#2639)
 - Change the debug message from the `sdk/trace.BatchSpanProcessor` to reflect the count is cumulative. (#2640)
+- Introduce new internal envconfig package for OTLP exporters (#2608)
 
 ### Fixed
 

exporters/otlp/internal/envconfig/envconfig.go

@@ -0,0 +1,148 @@
+// 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 envconfig // import "go.opentelemetry.io/otel/exporters/otlp/internal/envconfig"
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"errors"
+	"fmt"
+	"net/url"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// ConfigFn is the generic function used to set a config
+type ConfigFn func(*EnvOptionsReader)
+
+// EnvOptionsReader reads the required environment variables
+type EnvOptionsReader struct {
+	GetEnv    func(string) string
+	ReadFile  func(string) ([]byte, error)
+	Namespace string
+}
+
+// Apply runs every ConfigFn
+func (e *EnvOptionsReader) Apply(opts ...ConfigFn) {
+	for _, o := range opts {
+		o(e)
+	}
+}
+
+// GetEnvValue gets an OTLP environment variable value of the specified key
+// using the GetEnv function.
+// This function prepends the OTLP specified namespace to all key lookups.
+func (e *EnvOptionsReader) GetEnvValue(key string) (string, bool) {
+	v := strings.TrimSpace(e.GetEnv(keyWithNamespace(e.Namespace, key)))
+	return v, v != ""
+}
+
+// WithString retrieves the specified config and passes it to ConfigFn as a string
+func WithString(n string, fn func(string)) func(e *EnvOptionsReader) {
+	return func(e *EnvOptionsReader) {
+		if v, ok := e.GetEnvValue(n); ok {
+			fn(v)
+		}
+	}
+}
+
+// WithDuration retrieves the specified config and passes it to ConfigFn as a duration
+func WithDuration(n string, fn func(time.Duration)) func(e *EnvOptionsReader) {
+	return func(e *EnvOptionsReader) {
+		if v, ok := e.GetEnvValue(n); ok {
+			if d, err := strconv.Atoi(v); err == nil {
+				fn(time.Duration(d) * time.Millisecond)
+			}
+		}
+	}
+}
+
+// WithHeaders retrieves the specified config and passes it to ConfigFn as a map of HTTP headers
+func WithHeaders(n string, fn func(map[string]string)) func(e *EnvOptionsReader) {
+	return func(e *EnvOptionsReader) {
+		if v, ok := e.GetEnvValue(n); ok {
+			fn(stringToHeader(v))
+		}
+	}
+}
+
+// WithURL retrieves the specified config and passes it to ConfigFn as a net/url.URL
+func WithURL(n string, fn func(*url.URL)) func(e *EnvOptionsReader) {
+	return func(e *EnvOptionsReader) {
+		if v, ok := e.GetEnvValue(n); ok {
+			if u, err := url.Parse(v); err == nil {
+				fn(u)
+			}
+		}
+	}
+}
+
+// WithTLSConfig retrieves the specified config and passes it to ConfigFn as a crypto/tls.Config
+func WithTLSConfig(n string, fn func(*tls.Config)) func(e *EnvOptionsReader) {
+	return func(e *EnvOptionsReader) {
+		if v, ok := e.GetEnvValue(n); ok {
+			if b, err := e.ReadFile(v); err == nil {
+				if c, err := createTLSConfig(b); err == nil {
+					fn(c)
+				}
+			}
+		}
+	}
+}
+
+func keyWithNamespace(ns, key string) string {
+	if ns == "" {
+		return key
+	}
+	return fmt.Sprintf("%s_%s", ns, key)
+}
+
+func stringToHeader(value string) map[string]string {
+	headersPairs := strings.Split(value, ",")
+	headers := make(map[string]string)
+
+	for _, header := range headersPairs {
+		nameValue := strings.SplitN(header, "=", 2)
+		if len(nameValue) < 2 {
+			continue
+		}
+		name, err := url.QueryUnescape(nameValue[0])
+		if err != nil {
+			continue
+		}
+		trimmedName := strings.TrimSpace(name)
+		value, err := url.QueryUnescape(nameValue[1])
+		if err != nil {
+			continue
+		}
+		trimmedValue := strings.TrimSpace(value)
+
+		headers[trimmedName] = trimmedValue
+	}
+
+	return headers
+}
+
+func createTLSConfig(certBytes []byte) (*tls.Config, error) {
+	cp := x509.NewCertPool()
+	if ok := cp.AppendCertsFromPEM(certBytes); !ok {
+		return nil, errors.New("failed to append certificate to the cert pool")
+	}
+
+	return &tls.Config{
+		RootCAs: cp,
+	}, nil
+}

exporters/otlp/internal/envconfig/envconfig_test.go

@@ -0,0 +1,345 @@
+// 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 envconfig // import "go.opentelemetry.io/otel/exporters/otlp/internal/envconfig"
+
+import (
+	"crypto/tls"
+	"net/url"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+)
+
+const WeakCertificate = `
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
+`
+
+type testOption struct {
+	TestString   string
+	TestDuration time.Duration
+	TestHeaders  map[string]string
+	TestURL      *url.URL
+	TestTLS      *tls.Config
+}
+
+func TestEnvConfig(t *testing.T) {
+	parsedURL, err := url.Parse("https://example.com")
+	assert.NoError(t, err)
+
+	options := []testOption{}
+	for _, testcase := range []struct {
+		name            string
+		reader          EnvOptionsReader
+		configs         []ConfigFn
+		expectedOptions []testOption
+	}{
+		{
+			name: "with no namespace and a matching key",
+			reader: EnvOptionsReader{
+				GetEnv: func(n string) string {
+					if n == "HELLO" {
+						return "world"
+					}
+					return ""
+				},
+			},
+			configs: []ConfigFn{
+				WithString("HELLO", func(v string) {
+					options = append(options, testOption{TestString: v})
+				}),
+			},
+			expectedOptions: []testOption{
+				{
+					TestString: "world",
+				},
+			},
+		},
+		{
+			name: "with no namespace and a non-matching key",
+			reader: EnvOptionsReader{
+				GetEnv: func(n string) string {
+					if n == "HELLO" {
+						return "world"
+					}
+					return ""
+				},
+			},
+			configs: []ConfigFn{
+				WithString("HOLA", func(v string) {
+					options = append(options, testOption{TestString: v})
+				}),
+			},
+			expectedOptions: []testOption{},
+		},
+		{
+			name: "with a namespace and a matching key",
+			reader: EnvOptionsReader{
+				Namespace: "MY_NAMESPACE",
+				GetEnv: func(n string) string {
+					if n == "MY_NAMESPACE_HELLO" {
+						return "world"
+					}
+					return ""
+				},
+			},
+			configs: []ConfigFn{
+				WithString("HELLO", func(v string) {
+					options = append(options, testOption{TestString: v})
+				}),
+			},
+			expectedOptions: []testOption{
+				{
+					TestString: "world",
+				},
+			},
+		},
+		{
+			name: "with no namespace and a non-matching key",
+			reader: EnvOptionsReader{
+				Namespace: "MY_NAMESPACE",
+				GetEnv: func(n string) string {
+					if n == "HELLO" {
+						return "world"
+					}
+					return ""
+				},
+			},
+			configs: []ConfigFn{
+				WithString("HELLO", func(v string) {
+					options = append(options, testOption{TestString: v})
+				}),
+			},
+			expectedOptions: []testOption{},
+		},
+		{
+			name: "with a duration config",
+			reader: EnvOptionsReader{
+				GetEnv: func(n string) string {
+					if n == "HELLO" {
+						return "60"
+					}
+					return ""
+				},
+			},
+			configs: []ConfigFn{
+				WithDuration("HELLO", func(v time.Duration) {
+					options = append(options, testOption{TestDuration: v})
+				}),
+			},
+			expectedOptions: []testOption{
+				{
+					TestDuration: 60_000_000, // 60 milliseconds
+				},
+			},
+		},
+		{
+			name: "with an invalid duration config",
+			reader: EnvOptionsReader{
+				GetEnv: func(n string) string {
+					if n == "HELLO" {
+						return "world"
+					}
+					return ""
+				},
+			},
+			configs: []ConfigFn{
+				WithDuration("HELLO", func(v time.Duration) {
+					options = append(options, testOption{TestDuration: v})
+				}),
+			},
+			expectedOptions: []testOption{},
+		},
+		{
+			name: "with headers",
+			reader: EnvOptionsReader{
+				GetEnv: func(n string) string {
+					if n == "HELLO" {
+						return "userId=42,userName=alice"
+					}
+					return ""
+				},
+			},
+			configs: []ConfigFn{
+				WithHeaders("HELLO", func(v map[string]string) {
+					options = append(options, testOption{TestHeaders: v})
+				}),
+			},
+			expectedOptions: []testOption{
+				{
+					TestHeaders: map[string]string{
+						"userId":   "42",
+						"userName": "alice",
+					},
+				},
+			},
+		},
+		{
+			name: "with invalid headers",
+			reader: EnvOptionsReader{
+				GetEnv: func(n string) string {
+					if n == "HELLO" {
+						return "world"
+					}
+					return ""
+				},
+			},
+			configs: []ConfigFn{
+				WithHeaders("HELLO", func(v map[string]string) {
+					options = append(options, testOption{TestHeaders: v})
+				}),
+			},
+			expectedOptions: []testOption{
+				{
+					TestHeaders: map[string]string{},
+				},
+			},
+		},
+		{
+			name: "with URL",
+			reader: EnvOptionsReader{
+				GetEnv: func(n string) string {
+					if n == "HELLO" {
+						return "https://example.com"
+					}
+					return ""
+				},
+			},
+			configs: []ConfigFn{
+				WithURL("HELLO", func(v *url.URL) {
+					options = append(options, testOption{TestURL: v})
+				}),
+			},
+			expectedOptions: []testOption{
+				{
+					TestURL: parsedURL,
+				},
+			},
+		},
+		{
+			name: "with invalid URL",
+			reader: EnvOptionsReader{
+				GetEnv: func(n string) string {
+					if n == "HELLO" {
+						return "i nvalid://url"
+					}
+					return ""
+				},
+			},
+			configs: []ConfigFn{
+				WithURL("HELLO", func(v *url.URL) {
+					options = append(options, testOption{TestURL: v})
+				}),
+			},
+			expectedOptions: []testOption{},
+		},
+	} {
+		t.Run(testcase.name, func(t *testing.T) {
+			testcase.reader.Apply(testcase.configs...)
+			assert.Equal(t, testcase.expectedOptions, options)
+			options = []testOption{}
+		})
+	}
+}
+
+func TestWithTLSConfig(t *testing.T) {
+	tlsCert, err := createTLSConfig([]byte(WeakCertificate))
+	assert.NoError(t, err)
+
+	reader := EnvOptionsReader{
+		GetEnv: func(n string) string {
+			if n == "CERTIFICATE" {
+				return "/path/cert.pem"
+			}
+			return ""
+		},
+		ReadFile: func(p string) ([]byte, error) {
+			if p == "/path/cert.pem" {
+				return []byte(WeakCertificate), nil
+			}
+			return []byte{}, nil
+		},
+	}
+
+	var option testOption
+	reader.Apply(
+		WithTLSConfig("CERTIFICATE", func(v *tls.Config) {
+			option = testOption{TestTLS: v}
+		}))
+	assert.Equal(t, tlsCert.RootCAs.Subjects(), option.TestTLS.RootCAs.Subjects())
+}
+
+func TestStringToHeader(t *testing.T) {
+	tests := []struct {
+		name  string
+		value string
+		want  map[string]string
+	}{
+		{
+			name:  "simple test",
+			value: "userId=alice",
+			want:  map[string]string{"userId": "alice"},
+		},
+		{
+			name:  "simple test with spaces",
+			value: " userId = alice  ",
+			want:  map[string]string{"userId": "alice"},
+		},
+		{
+			name:  "multiples headers encoded",
+			value: "userId=alice,serverNode=DF%3A28,isProduction=false",
+			want: map[string]string{
+				"userId":       "alice",
+				"serverNode":   "DF:28",
+				"isProduction": "false",
+			},
+		},
+		{
+			name:  "invalid headers format",
+			value: "userId:alice",
+			want:  map[string]string{},
+		},
+		{
+			name:  "invalid key",
+			value: "%XX=missing,userId=alice",
+			want: map[string]string{
+				"userId": "alice",
+			},
+		},
+		{
+			name:  "invalid value",
+			value: "missing=%XX,userId=alice",
+			want: map[string]string{
+				"userId": "alice",
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert.Equal(t, tt.want, stringToHeader(tt.value))
+		})
+	}
+}

exporters/otlp/otlpmetric/internal/otlpconfig/envconfig.go

@@ -16,66 +16,58 @@ package otlpconfig // import "go.opentelemetry.io/otel/exporters/otlp/otlpmetric
 
 import (
 	"crypto/tls"
-	"fmt"
 	"io/ioutil"
 	"net/url"
 	"os"
 	"path"
-	"strconv"
 	"strings"
 	"time"
 
-	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/exporters/otlp/internal/envconfig"
 )
 
-var DefaultEnvOptionsReader = EnvOptionsReader{
-	GetEnv:   os.Getenv,
-	ReadFile: ioutil.ReadFile,
+// DefaultEnvOptionsReader is the default environments reader
+var DefaultEnvOptionsReader = envconfig.EnvOptionsReader{
+	GetEnv:    os.Getenv,
+	ReadFile:  ioutil.ReadFile,
+	Namespace: "OTEL_EXPORTER_OTLP",
 }
 
+// ApplyGRPCEnvConfigs applies the env configurations for gRPC
 func ApplyGRPCEnvConfigs(cfg Config) Config {
-	return DefaultEnvOptionsReader.ApplyGRPCEnvConfigs(cfg)
-}
-
-func ApplyHTTPEnvConfigs(cfg Config) Config {
-	return DefaultEnvOptionsReader.ApplyHTTPEnvConfigs(cfg)
-}
-
-type EnvOptionsReader struct {
-	GetEnv   func(string) string
-	ReadFile func(filename string) ([]byte, error)
-}
-
-func (e *EnvOptionsReader) ApplyHTTPEnvConfigs(cfg Config) Config {
-	opts := e.GetOptionsFromEnv()
-	for _, opt := range opts {
-		cfg = opt.ApplyHTTPOption(cfg)
-	}
-	return cfg
-}
-
-func (e *EnvOptionsReader) ApplyGRPCEnvConfigs(cfg Config) Config {
-	opts := e.GetOptionsFromEnv()
+	opts := getOptionsFromEnv()
 	for _, opt := range opts {
 		cfg = opt.ApplyGRPCOption(cfg)
 	}
 	return cfg
 }
 
-func (e *EnvOptionsReader) GetOptionsFromEnv() []GenericOption {
-	var opts []GenericOption
+// ApplyHTTPEnvConfigs applies the env configurations for HTTP
+func ApplyHTTPEnvConfigs(cfg Config) Config {
+	opts := getOptionsFromEnv()
+	for _, opt := range opts {
+		cfg = opt.ApplyHTTPOption(cfg)
+	}
+	return cfg
+}
 
-	// Endpoint
-	if v, ok := e.getEnvValue("METRICS_ENDPOINT"); ok {
-		u, err := url.Parse(v)
-		// Ignore invalid values.
-		if err == nil {
-			// This is used to set the scheme for OTLP/HTTP.
-			if insecureSchema(u.Scheme) {
-				opts = append(opts, WithInsecure())
-			} else {
-				opts = append(opts, WithSecure())
-			}
+func getOptionsFromEnv() []GenericOption {
+	opts := []GenericOption{}
+
+	DefaultEnvOptionsReader.Apply(
+		envconfig.WithURL("ENDPOINT", func(u *url.URL) {
+			opts = append(opts, withEndpointScheme(u))
+			opts = append(opts, newSplitOption(func(cfg Config) Config {
+				cfg.Metrics.Endpoint = u.Host
+				// For OTLP/HTTP endpoint URLs without a per-signal
+				// configuration, the passed endpoint is used as a base URL
+				// and the signals are sent to these paths relative to that.
+				cfg.Metrics.URLPath = path.Join(u.Path, DefaultMetricsPath)
+				return cfg
+			}, withEndpointForGRPC(u)))
+		}),
+		envconfig.WithURL("METRICS_ENDPOINT", func(u *url.URL) {
+			opts = append(opts, withEndpointScheme(u))
 			opts = append(opts, newSplitOption(func(cfg Config) Config {
 				cfg.Metrics.Endpoint = u.Host
 				// For endpoint URLs for OTLP/HTTP per-signal variables, the
@@ -88,141 +80,50 @@ func (e *EnvOptionsReader) GetOptionsFromEnv() []GenericOption {
 				}
 				cfg.Metrics.URLPath = path
 				return cfg
-			}, func(cfg Config) Config {
-				// For OTLP/gRPC endpoints, this is the target to which the
-				// exporter is going to send telemetry.
-				cfg.Metrics.Endpoint = path.Join(u.Host, u.Path)
-				return cfg
-			}))
-		}
-	} else if v, ok = e.getEnvValue("ENDPOINT"); ok {
-		u, err := url.Parse(v)
-		// Ignore invalid values.
-		if err == nil {
-			// This is used to set the scheme for OTLP/HTTP.
-			if insecureSchema(u.Scheme) {
-				opts = append(opts, WithInsecure())
-			} else {
-				opts = append(opts, WithSecure())
-			}
-			opts = append(opts, newSplitOption(func(cfg Config) Config {
-				cfg.Metrics.Endpoint = u.Host
-				// For OTLP/HTTP endpoint URLs without a per-signal
-				// configuration, the passed endpoint is used as a base URL
-				// and the signals are sent to these paths relative to that.
-				cfg.Metrics.URLPath = path.Join(u.Path, DefaultMetricsPath)
-				return cfg
-			}, func(cfg Config) Config {
-				// For OTLP/gRPC endpoints, this is the target to which the
-				// exporter is going to send telemetry.
-				cfg.Metrics.Endpoint = path.Join(u.Host, u.Path)
-				return cfg
-			}))
-		}
-	}
-
-	// Certificate File
-	if path, ok := e.getEnvValue("CERTIFICATE"); ok {
-		if tls, err := e.readTLSConfig(path); err == nil {
-			opts = append(opts, WithTLSClientConfig(tls))
-		} else {
-			otel.Handle(fmt.Errorf("failed to configure otlp exporter certificate '%s': %w", path, err))
-		}
-	}
-	if path, ok := e.getEnvValue("METRICS_CERTIFICATE"); ok {
-		if tls, err := e.readTLSConfig(path); err == nil {
-			opts = append(opts, WithTLSClientConfig(tls))
-		} else {
-			otel.Handle(fmt.Errorf("failed to configure otlp exporter certificate '%s': %w", path, err))
-		}
-	}
-
-	// Headers
-	if h, ok := e.getEnvValue("HEADERS"); ok {
-		opts = append(opts, WithHeaders(stringToHeader(h)))
-	}
-	if h, ok := e.getEnvValue("METRICS_HEADERS"); ok {
-		opts = append(opts, WithHeaders(stringToHeader(h)))
-	}
-
-	// Compression
-	if c, ok := e.getEnvValue("COMPRESSION"); ok {
-		opts = append(opts, WithCompression(stringToCompression(c)))
-	}
-	if c, ok := e.getEnvValue("METRICS_COMPRESSION"); ok {
-		opts = append(opts, WithCompression(stringToCompression(c)))
-	}
-
-	// Timeout
-	if t, ok := e.getEnvValue("TIMEOUT"); ok {
-		if d, err := strconv.Atoi(t); err == nil {
-			opts = append(opts, WithTimeout(time.Duration(d)*time.Millisecond))
-		}
-	}
-	if t, ok := e.getEnvValue("METRICS_TIMEOUT"); ok {
-		if d, err := strconv.Atoi(t); err == nil {
-			opts = append(opts, WithTimeout(time.Duration(d)*time.Millisecond))
-		}
-	}
+			}, withEndpointForGRPC(u)))
+		}),
+		envconfig.WithTLSConfig("CERTIFICATE", func(c *tls.Config) { opts = append(opts, WithTLSClientConfig(c)) }),
+		envconfig.WithTLSConfig("METRICS_CERTIFICATE", func(c *tls.Config) { opts = append(opts, WithTLSClientConfig(c)) }),
+		envconfig.WithHeaders("HEADERS", func(h map[string]string) { opts = append(opts, WithHeaders(h)) }),
+		envconfig.WithHeaders("METRICS_HEADERS", func(h map[string]string) { opts = append(opts, WithHeaders(h)) }),
+		WithEnvCompression("COMPRESSION", func(c Compression) { opts = append(opts, WithCompression(c)) }),
+		WithEnvCompression("METRICS_COMPRESSION", func(c Compression) { opts = append(opts, WithCompression(c)) }),
+		envconfig.WithDuration("TIMEOUT", func(d time.Duration) { opts = append(opts, WithTimeout(d)) }),
+		envconfig.WithDuration("METRICS_TIMEOUT", func(d time.Duration) { opts = append(opts, WithTimeout(d)) }),
+	)
 
 	return opts
 }
 
-func insecureSchema(schema string) bool {
-	switch strings.ToLower(schema) {
+func withEndpointForGRPC(u *url.URL) func(cfg Config) Config {
+	return func(cfg Config) Config {
+		// For OTLP/gRPC endpoints, this is the target to which the
+		// exporter is going to send telemetry.
+		cfg.Metrics.Endpoint = path.Join(u.Host, u.Path)
+		return cfg
+	}
+}
+
+// WithEnvCompression retrieves the specified config and passes it to ConfigFn as a Compression
+func WithEnvCompression(n string, fn func(Compression)) func(e *envconfig.EnvOptionsReader) {
+	return func(e *envconfig.EnvOptionsReader) {
+		if v, ok := e.GetEnvValue(n); ok {
+			cp := NoCompression
+			switch v {
+			case "gzip":
+				cp = GzipCompression
+			}
+
+			fn(cp)
+		}
+	}
+}
+
+func withEndpointScheme(u *url.URL) GenericOption {
+	switch strings.ToLower(u.Scheme) {
 	case "http", "unix":
-		return true
+		return WithInsecure()
 	default:
-		return false
+		return WithSecure()
 	}
 }
-
-// getEnvValue gets an OTLP environment variable value of the specified key using the GetEnv function.
-// This function already prepends the OTLP prefix to all key lookup.
-func (e *EnvOptionsReader) getEnvValue(key string) (string, bool) {
-	v := strings.TrimSpace(e.GetEnv(fmt.Sprintf("OTEL_EXPORTER_OTLP_%s", key)))
-	return v, v != ""
-}
-
-func (e *EnvOptionsReader) readTLSConfig(path string) (*tls.Config, error) {
-	b, err := e.ReadFile(path)
-	if err != nil {
-		return nil, err
-	}
-	return CreateTLSConfig(b)
-}
-
-func stringToCompression(value string) Compression {
-	switch value {
-	case "gzip":
-		return GzipCompression
-	}
-
-	return NoCompression
-}
-
-func stringToHeader(value string) map[string]string {
-	headersPairs := strings.Split(value, ",")
-	headers := make(map[string]string)
-
-	for _, header := range headersPairs {
-		nameValue := strings.SplitN(header, "=", 2)
-		if len(nameValue) < 2 {
-			continue
-		}
-		name, err := url.QueryUnescape(nameValue[0])
-		if err != nil {
-			continue
-		}
-		trimmedName := strings.TrimSpace(name)
-		value, err := url.QueryUnescape(nameValue[1])
-		if err != nil {
-			continue
-		}
-		trimmedValue := strings.TrimSpace(value)
-
-		headers[trimmedName] = trimmedValue
-	}
-
-	return headers
-}

exporters/otlp/otlpmetric/internal/otlpconfig/envconfig_test.go

@@ -13,63 +13,3 @@
 // limitations under the License.
 
 package otlpconfig
-
-import (
-	"reflect"
-	"testing"
-)
-
-func TestStringToHeader(t *testing.T) {
-	tests := []struct {
-		name  string
-		value string
-		want  map[string]string
-	}{
-		{
-			name:  "simple test",
-			value: "userId=alice",
-			want:  map[string]string{"userId": "alice"},
-		},
-		{
-			name:  "simple test with spaces",
-			value: " userId = alice  ",
-			want:  map[string]string{"userId": "alice"},
-		},
-		{
-			name:  "multiples headers encoded",
-			value: "userId=alice,serverNode=DF%3A28,isProduction=false",
-			want: map[string]string{
-				"userId":       "alice",
-				"serverNode":   "DF:28",
-				"isProduction": "false",
-			},
-		},
-		{
-			name:  "invalid headers format",
-			value: "userId:alice",
-			want:  map[string]string{},
-		},
-		{
-			name:  "invalid key",
-			value: "%XX=missing,userId=alice",
-			want: map[string]string{
-				"userId": "alice",
-			},
-		},
-		{
-			name:  "invalid value",
-			value: "missing=%XX,userId=alice",
-			want: map[string]string{
-				"userId": "alice",
-			},
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			if got := stringToHeader(tt.value); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("stringToHeader() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}

exporters/otlp/otlpmetric/internal/otlpconfig/options_test.go

@@ -21,6 +21,7 @@ import (
 
 	"github.com/stretchr/testify/assert"
 
+	"go.opentelemetry.io/otel/exporters/otlp/internal/envconfig"
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/internal/otlpconfig"
 )
 
@@ -383,9 +384,10 @@ func TestConfigs(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			origEOR := otlpconfig.DefaultEnvOptionsReader
-			otlpconfig.DefaultEnvOptionsReader = otlpconfig.EnvOptionsReader{
-				GetEnv:   tt.env.getEnv,
-				ReadFile: tt.fileReader.readFile,
+			otlpconfig.DefaultEnvOptionsReader = envconfig.EnvOptionsReader{
+				GetEnv:    tt.env.getEnv,
+				ReadFile:  tt.fileReader.readFile,
+				Namespace: "OTEL_EXPORTER_OTLP",
 			}
 			t.Cleanup(func() { otlpconfig.DefaultEnvOptionsReader = origEOR })
 

exporters/otlp/otlptrace/internal/otlpconfig/envconfig.go

@@ -16,66 +16,58 @@ package otlpconfig // import "go.opentelemetry.io/otel/exporters/otlp/otlptrace/
 
 import (
 	"crypto/tls"
-	"fmt"
 	"io/ioutil"
 	"net/url"
 	"os"
 	"path"
-	"strconv"
 	"strings"
 	"time"
 
-	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/exporters/otlp/internal/envconfig"
 )
 
-var DefaultEnvOptionsReader = EnvOptionsReader{
-	GetEnv:   os.Getenv,
-	ReadFile: ioutil.ReadFile,
+// DefaultEnvOptionsReader is the default environments reader
+var DefaultEnvOptionsReader = envconfig.EnvOptionsReader{
+	GetEnv:    os.Getenv,
+	ReadFile:  ioutil.ReadFile,
+	Namespace: "OTEL_EXPORTER_OTLP",
 }
 
+// ApplyGRPCEnvConfigs applies the env configurations for gRPC
 func ApplyGRPCEnvConfigs(cfg Config) Config {
-	return DefaultEnvOptionsReader.ApplyGRPCEnvConfigs(cfg)
-}
-
-func ApplyHTTPEnvConfigs(cfg Config) Config {
-	return DefaultEnvOptionsReader.ApplyHTTPEnvConfigs(cfg)
-}
-
-type EnvOptionsReader struct {
-	GetEnv   func(string) string
-	ReadFile func(filename string) ([]byte, error)
-}
-
-func (e *EnvOptionsReader) ApplyHTTPEnvConfigs(cfg Config) Config {
-	opts := e.GetOptionsFromEnv()
-	for _, opt := range opts {
-		cfg = opt.ApplyHTTPOption(cfg)
-	}
-	return cfg
-}
-
-func (e *EnvOptionsReader) ApplyGRPCEnvConfigs(cfg Config) Config {
-	opts := e.GetOptionsFromEnv()
+	opts := getOptionsFromEnv()
 	for _, opt := range opts {
 		cfg = opt.ApplyGRPCOption(cfg)
 	}
 	return cfg
 }
 
-func (e *EnvOptionsReader) GetOptionsFromEnv() []GenericOption {
-	var opts []GenericOption
+// ApplyHTTPEnvConfigs applies the env configurations for HTTP
+func ApplyHTTPEnvConfigs(cfg Config) Config {
+	opts := getOptionsFromEnv()
+	for _, opt := range opts {
+		cfg = opt.ApplyHTTPOption(cfg)
+	}
+	return cfg
+}
 
-	// Endpoint
-	if v, ok := e.getEnvValue("TRACES_ENDPOINT"); ok {
-		u, err := url.Parse(v)
-		// Ignore invalid values.
-		if err == nil {
-			// This is used to set the scheme for OTLP/HTTP.
-			if insecureSchema(u.Scheme) {
-				opts = append(opts, WithInsecure())
-			} else {
-				opts = append(opts, WithSecure())
-			}
+func getOptionsFromEnv() []GenericOption {
+	opts := []GenericOption{}
+
+	DefaultEnvOptionsReader.Apply(
+		envconfig.WithURL("ENDPOINT", func(u *url.URL) {
+			opts = append(opts, withEndpointScheme(u))
+			opts = append(opts, newSplitOption(func(cfg Config) Config {
+				cfg.Traces.Endpoint = u.Host
+				// For OTLP/HTTP endpoint URLs without a per-signal
+				// configuration, the passed endpoint is used as a base URL
+				// and the signals are sent to these paths relative to that.
+				cfg.Traces.URLPath = path.Join(u.Path, DefaultTracesPath)
+				return cfg
+			}, withEndpointForGRPC(u)))
+		}),
+		envconfig.WithURL("TRACES_ENDPOINT", func(u *url.URL) {
+			opts = append(opts, withEndpointScheme(u))
 			opts = append(opts, newSplitOption(func(cfg Config) Config {
 				cfg.Traces.Endpoint = u.Host
 				// For endpoint URLs for OTLP/HTTP per-signal variables, the
@@ -88,140 +80,50 @@ func (e *EnvOptionsReader) GetOptionsFromEnv() []GenericOption {
 				}
 				cfg.Traces.URLPath = path
 				return cfg
-			}, func(cfg Config) Config {
-				// For OTLP/gRPC endpoints, this is the target to which the
-				// exporter is going to send telemetry.
-				cfg.Traces.Endpoint = path.Join(u.Host, u.Path)
-				return cfg
-			}))
-		}
-	} else if v, ok = e.getEnvValue("ENDPOINT"); ok {
-		u, err := url.Parse(v)
-		// Ignore invalid values.
-		if err == nil {
-			// This is used to set the scheme for OTLP/HTTP.
-			if insecureSchema(u.Scheme) {
-				opts = append(opts, WithInsecure())
-			} else {
-				opts = append(opts, WithSecure())
-			}
-			opts = append(opts, newSplitOption(func(cfg Config) Config {
-				cfg.Traces.Endpoint = u.Host
-				// For OTLP/HTTP endpoint URLs without a per-signal
-				// configuration, the passed endpoint is used as a base URL
-				// and the signals are sent to these paths relative to that.
-				cfg.Traces.URLPath = path.Join(u.Path, DefaultTracesPath)
-				return cfg
-			}, func(cfg Config) Config {
-				// For OTLP/gRPC endpoints, this is the target to which the
-				// exporter is going to send telemetry.
-				cfg.Traces.Endpoint = path.Join(u.Host, u.Path)
-				return cfg
-			}))
-		}
-	}
-
-	// Certificate File
-	if path, ok := e.getEnvValue("CERTIFICATE"); ok {
-		if tls, err := e.readTLSConfig(path); err == nil {
-			opts = append(opts, WithTLSClientConfig(tls))
-		} else {
-			otel.Handle(fmt.Errorf("failed to configure otlp exporter certificate '%s': %w", path, err))
-		}
-	}
-	if path, ok := e.getEnvValue("TRACES_CERTIFICATE"); ok {
-		if tls, err := e.readTLSConfig(path); err == nil {
-			opts = append(opts, WithTLSClientConfig(tls))
-		} else {
-			otel.Handle(fmt.Errorf("failed to configure otlp traces exporter certificate '%s': %w", path, err))
-		}
-	}
-
-	// Headers
-	if h, ok := e.getEnvValue("HEADERS"); ok {
-		opts = append(opts, WithHeaders(stringToHeader(h)))
-	}
-	if h, ok := e.getEnvValue("TRACES_HEADERS"); ok {
-		opts = append(opts, WithHeaders(stringToHeader(h)))
-	}
-
-	// Compression
-	if c, ok := e.getEnvValue("COMPRESSION"); ok {
-		opts = append(opts, WithCompression(stringToCompression(c)))
-	}
-	if c, ok := e.getEnvValue("TRACES_COMPRESSION"); ok {
-		opts = append(opts, WithCompression(stringToCompression(c)))
-	}
-	// Timeout
-	if t, ok := e.getEnvValue("TIMEOUT"); ok {
-		if d, err := strconv.Atoi(t); err == nil {
-			opts = append(opts, WithTimeout(time.Duration(d)*time.Millisecond))
-		}
-	}
-	if t, ok := e.getEnvValue("TRACES_TIMEOUT"); ok {
-		if d, err := strconv.Atoi(t); err == nil {
-			opts = append(opts, WithTimeout(time.Duration(d)*time.Millisecond))
-		}
-	}
+			}, withEndpointForGRPC(u)))
+		}),
+		envconfig.WithTLSConfig("CERTIFICATE", func(c *tls.Config) { opts = append(opts, WithTLSClientConfig(c)) }),
+		envconfig.WithTLSConfig("TRACES_CERTIFICATE", func(c *tls.Config) { opts = append(opts, WithTLSClientConfig(c)) }),
+		envconfig.WithHeaders("HEADERS", func(h map[string]string) { opts = append(opts, WithHeaders(h)) }),
+		envconfig.WithHeaders("TRACES_HEADERS", func(h map[string]string) { opts = append(opts, WithHeaders(h)) }),
+		WithEnvCompression("COMPRESSION", func(c Compression) { opts = append(opts, WithCompression(c)) }),
+		WithEnvCompression("TRACES_COMPRESSION", func(c Compression) { opts = append(opts, WithCompression(c)) }),
+		envconfig.WithDuration("TIMEOUT", func(d time.Duration) { opts = append(opts, WithTimeout(d)) }),
+		envconfig.WithDuration("TRACES_TIMEOUT", func(d time.Duration) { opts = append(opts, WithTimeout(d)) }),
+	)
 
 	return opts
 }
 
-func insecureSchema(schema string) bool {
-	switch strings.ToLower(schema) {
+func withEndpointScheme(u *url.URL) GenericOption {
+	switch strings.ToLower(u.Scheme) {
 	case "http", "unix":
-		return true
+		return WithInsecure()
 	default:
-		return false
+		return WithSecure()
 	}
 }
 
-// getEnvValue gets an OTLP environment variable value of the specified key using the GetEnv function.
-// This function already prepends the OTLP prefix to all key lookup.
-func (e *EnvOptionsReader) getEnvValue(key string) (string, bool) {
-	v := strings.TrimSpace(e.GetEnv(fmt.Sprintf("OTEL_EXPORTER_OTLP_%s", key)))
-	return v, v != ""
-}
-
-func (e *EnvOptionsReader) readTLSConfig(path string) (*tls.Config, error) {
-	b, err := e.ReadFile(path)
-	if err != nil {
-		return nil, err
+func withEndpointForGRPC(u *url.URL) func(cfg Config) Config {
+	return func(cfg Config) Config {
+		// For OTLP/gRPC endpoints, this is the target to which the
+		// exporter is going to send telemetry.
+		cfg.Traces.Endpoint = path.Join(u.Host, u.Path)
+		return cfg
 	}
-	return CreateTLSConfig(b)
 }
 
-func stringToCompression(value string) Compression {
-	switch value {
-	case "gzip":
-		return GzipCompression
-	}
+// WithEnvCompression retrieves the specified config and passes it to ConfigFn as a Compression
+func WithEnvCompression(n string, fn func(Compression)) func(e *envconfig.EnvOptionsReader) {
+	return func(e *envconfig.EnvOptionsReader) {
+		if v, ok := e.GetEnvValue(n); ok {
+			cp := NoCompression
+			switch v {
+			case "gzip":
+				cp = GzipCompression
+			}
 
-	return NoCompression
-}
-
-func stringToHeader(value string) map[string]string {
-	headersPairs := strings.Split(value, ",")
-	headers := make(map[string]string)
-
-	for _, header := range headersPairs {
-		nameValue := strings.SplitN(header, "=", 2)
-		if len(nameValue) < 2 {
-			continue
+			fn(cp)
 		}
-		name, err := url.QueryUnescape(nameValue[0])
-		if err != nil {
-			continue
-		}
-		trimmedName := strings.TrimSpace(name)
-		value, err := url.QueryUnescape(nameValue[1])
-		if err != nil {
-			continue
-		}
-		trimmedValue := strings.TrimSpace(value)
-
-		headers[trimmedName] = trimmedValue
 	}
-
-	return headers
 }

exporters/otlp/otlptrace/internal/otlpconfig/envconfig_test.go

@@ -13,63 +13,3 @@
 // limitations under the License.
 
 package otlpconfig
-
-import (
-	"reflect"
-	"testing"
-)
-
-func TestStringToHeader(t *testing.T) {
-	tests := []struct {
-		name  string
-		value string
-		want  map[string]string
-	}{
-		{
-			name:  "simple test",
-			value: "userId=alice",
-			want:  map[string]string{"userId": "alice"},
-		},
-		{
-			name:  "simple test with spaces",
-			value: " userId = alice  ",
-			want:  map[string]string{"userId": "alice"},
-		},
-		{
-			name:  "multiples headers encoded",
-			value: "userId=alice,serverNode=DF%3A28,isProduction=false",
-			want: map[string]string{
-				"userId":       "alice",
-				"serverNode":   "DF:28",
-				"isProduction": "false",
-			},
-		},
-		{
-			name:  "invalid headers format",
-			value: "userId:alice",
-			want:  map[string]string{},
-		},
-		{
-			name:  "invalid key",
-			value: "%XX=missing,userId=alice",
-			want: map[string]string{
-				"userId": "alice",
-			},
-		},
-		{
-			name:  "invalid value",
-			value: "missing=%XX,userId=alice",
-			want: map[string]string{
-				"userId": "alice",
-			},
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			if got := stringToHeader(tt.value); !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("stringToHeader() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}

exporters/otlp/otlptrace/internal/otlpconfig/options_test.go

@@ -21,6 +21,7 @@ import (
 
 	"github.com/stretchr/testify/assert"
 
+	"go.opentelemetry.io/otel/exporters/otlp/internal/envconfig"
 	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/internal/otlpconfig"
 )
 
@@ -381,9 +382,10 @@ func TestConfigs(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			origEOR := otlpconfig.DefaultEnvOptionsReader
-			otlpconfig.DefaultEnvOptionsReader = otlpconfig.EnvOptionsReader{
-				GetEnv:   tt.env.getEnv,
-				ReadFile: tt.fileReader.readFile,
+			otlpconfig.DefaultEnvOptionsReader = envconfig.EnvOptionsReader{
+				GetEnv:    tt.env.getEnv,
+				ReadFile:  tt.fileReader.readFile,
+				Namespace: "OTEL_EXPORTER_OTLP",
 			}
 			t.Cleanup(func() { otlpconfig.DefaultEnvOptionsReader = origEOR })