Handle empty env vars as it they were not set (#3764)

* Handle empty env vars as it they were not set

* Add changelog entry

* Add missing unit test

CHANGELOG.md

@@ -8,6 +8,10 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 ## [Unreleased]
 
+### Fixed
+
+- Handle empty environment variable as it they were not set. (#3764)
+
 ## [1.14.0/0.37.0/0.0.4] 2023-02-27
 
 This release is the last to support [Go 1.18].

exporters/jaeger/env.go

@@ -37,7 +37,7 @@ const (
 
 // envOr returns an env variable's value if it is exists or the default if not.
 func envOr(key, defaultValue string) string {
-	if v, ok := os.LookupEnv(key); ok && v != "" {
+	if v := os.Getenv(key); v != "" {
 		return v
 	}
 	return defaultValue

exporters/zipkin/env.go

@@ -24,7 +24,7 @@ const (
 
 // envOr returns an env variable's value if it is exists or the default if not.
 func envOr(key, defaultValue string) string {
-	if v, ok := os.LookupEnv(key); ok && v != "" {
+	if v := os.Getenv(key); v != "" {
 		return v
 	}
 	return defaultValue

sdk/internal/env/env.go

@@ -70,8 +70,8 @@ const (
 // returned.
 func firstInt(defaultValue int, keys ...string) int {
 	for _, key := range keys {
-		value, ok := os.LookupEnv(key)
-		if !ok {
+		value := os.Getenv(key)
+		if value == "" {
 			continue
 		}
 
@@ -88,10 +88,10 @@ func firstInt(defaultValue int, keys ...string) int {
 }
 
 // IntEnvOr returns the int value of the environment variable with name key if
-// it exists and the value is an int. Otherwise, defaultValue is returned.
+// it exists, it is not empty, and the value is an int. Otherwise, defaultValue is returned.
 func IntEnvOr(key string, defaultValue int) int {
-	value, ok := os.LookupEnv(key)
-	if !ok {
+	value := os.Getenv(key)
+	if value == "" {
 		return defaultValue
 	}
 

sdk/internal/env/env_test.go

@@ -96,6 +96,7 @@ func TestEnvParse(t *testing.T) {
 		envVal    = 2500
 		envValStr = "2500"
 		invalid   = "localhost"
+		empty     = ""
 	)
 
 	for _, tc := range testCases {
@@ -113,6 +114,9 @@ func TestEnvParse(t *testing.T) {
 
 					require.NoError(t, os.Setenv(key, invalid))
 					assert.Equal(t, defVal, tc.f(defVal), "invalid value")
+
+					require.NoError(t, os.Setenv(key, empty))
+					assert.Equal(t, defVal, tc.f(defVal), "empty value")
 				})
 			}
 		})