Fix config load env, and New func error handling

aws/session/doc.go

@@ -124,7 +124,7 @@ file for the shared config. If not set the file will be loaded from
 $HOME/.aws/config on Linux/Unix based systems, and
 %USERPROFILE%\.aws\config on Windows.
 
-	AWS_SHARED_CONFIG_FILE=$HOME/my_shared_config
+	AWS_CONFIG_FILE=$HOME/my_shared_config
 
 Shared Config Fields
 

aws/session/env_config.go

@@ -73,7 +73,7 @@ type envConfig struct {
 	// $HOME/.aws/config on Linux/Unix based systems, and
 	// %USERPROFILE%\.aws\config on Windows.
 	//
-	//	AWS_SHARED_CONFIG_FILE=$HOME/my_shared_config
+	//	AWS_CONFIG_FILE=$HOME/my_shared_config
 	SharedConfigFile string
 }
 

aws/session/session.go

@@ -2,6 +2,7 @@ package session
 
 import (
 	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/aws/awserr"
 	"github.com/aws/aws-sdk-go/aws/client"
 	"github.com/aws/aws-sdk-go/aws/corehandlers"
 	"github.com/aws/aws-sdk-go/aws/credentials"
@@ -30,30 +31,41 @@ type Session struct {
 //
 // If the AWS_SDK_LOAD_CONFIG environment is set to a truthy value, the New
 // method could now encounter an error when loading the configuration. When
-// the environment variable is set New will panic if an error occurs. The Build
-// methods should be used instead to avoid this panic, as they will return an
-// error if one occurs.
+// The environment variable is set, and an error occurs, New will return a
+// session that will fail all requests reporting the error that occured while
+// loading the session. Use the Build funcs to get the error when creating
+// the session.
 //
 // If the AWS_SDK_LOAD_CONFIG environment variable is set to a truthy value
 // the shared config file (~/.aws/config) will also be loaded, in addition to
 // the shared credentials file (~/.aws/config). Values set in both the shared
 // shared config, and shared credentials will be taken from the shared
 // credentials file.
 //
-// Deprecated: Use Build instead. Build has the same functionality as New
-// except an error is returned instead of panic.
+// Deprecated: Use Build instead. Build funcs have the same functionality as
+// New except an error can be returned when the func is called instead of
+// waiting to receive an error until a request is made.
 func New(cfgs ...*aws.Config) *Session {
 	// load initial config from environment
 	envCfg := loadEnvConfig()
 
 	if envCfg.EnableSharedConfig {
-		// Old session.New expected all errors to be discovered when
-		// a request is made, and would report the errors then. This
-		// needs to be mocked.
 		s, err := buildSession(envCfg, cfgs...)
 		if err != nil {
-			// TODO error message
-			panic(err)
+			// Old session.New expected all errors to be discovered when
+			// a request is made, and would report the errors then. This
+			// needs to be replicated if an error occurs while creating
+			// the session.
+			msg := "failed to create session with AWS_SDK_LOAD_CONFIG enabled. " +
+				"Use session.Build to handle errors occuring during session creation."
+
+			// Session creation failed, need to report the error and prevent
+			// any requests from succeeding.
+			s = &Session{Config: defaults.Config()}
+			s.Config.Logger.Log("ERROR:", msg, "Error:", err)
+			s.Handlers.Validate.PushBack(func(r *request.Request) {
+				r.Error = awserr.New("SharedConfigLoadError", msg, err)
+			})
 		}
 		return s
 	}

aws/session/session_test.go

@@ -11,15 +11,15 @@ import (
 	"github.com/stretchr/testify/assert"
 
 	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/aws/awserr"
 	"github.com/aws/aws-sdk-go/aws/credentials"
 	"github.com/aws/aws-sdk-go/aws/defaults"
+	"github.com/aws/aws-sdk-go/service/s3"
 )
 
 func TestNewDefaultSession(t *testing.T) {
-	env := stashEnv()
-	defer popEnv(env)
-	os.Setenv("AWS_SHARED_CONFIG_FILE", "file_not_exists")
-	os.Setenv("AWS_SHARED_CREDENTIALS_FILE", "file_not_exists")
+	oldEnv := initSessionTestEnv()
+	defer popEnv(oldEnv)
 
 	s := New(&aws.Config{Region: aws.String("region")})
 
@@ -30,8 +30,8 @@ func TestNewDefaultSession(t *testing.T) {
 }
 
 func TestNew_WithCustomCreds(t *testing.T) {
-	env := stashEnv()
-	defer popEnv(env)
+	oldEnv := initSessionTestEnv()
+	defer popEnv(oldEnv)
 
 	customCreds := credentials.NewStaticCredentials("AKID", "SECRET", "TOKEN")
 	s := New(&aws.Config{Credentials: customCreds})
@@ -40,8 +40,8 @@ func TestNew_WithCustomCreds(t *testing.T) {
 }
 
 func TestSessionCopy(t *testing.T) {
-	env := stashEnv()
-	defer popEnv(env)
+	oldEnv := initSessionTestEnv()
+	defer popEnv(oldEnv)
 
 	os.Setenv("AWS_REGION", "orig_region")
 
@@ -67,10 +67,8 @@ func TestSessionClientConfig(t *testing.T) {
 }
 
 func TestBuildFromProfile(t *testing.T) {
-	env := stashEnv()
-	defer popEnv(env)
-	os.Setenv("AWS_SHARED_CONFIG_FILE", "file_not_exists")
-	os.Setenv("AWS_SHARED_CREDENTIALS_FILE", "file_not_exists")
+	oldEnv := initSessionTestEnv()
+	defer popEnv(oldEnv)
 
 	os.Setenv("AWS_SHARED_CREDENTIALS_FILE", testConfigFilename)
 	os.Setenv("AWS_PROFILE", "other_profile")
@@ -89,10 +87,8 @@ func TestBuildFromProfile(t *testing.T) {
 }
 
 func TestBuildFromProfile_WithSharedConfig(t *testing.T) {
-	env := stashEnv()
-	defer popEnv(env)
-	os.Setenv("AWS_SHARED_CONFIG_FILE", "file_not_exists")
-	os.Setenv("AWS_SHARED_CREDENTIALS_FILE", "file_not_exists")
+	oldEnv := initSessionTestEnv()
+	defer popEnv(oldEnv)
 
 	os.Setenv("AWS_SDK_LOAD_CONFIG", "1")
 	os.Setenv("AWS_SHARED_CREDENTIALS_FILE", testConfigFilename)
@@ -112,10 +108,8 @@ func TestBuildFromProfile_WithSharedConfig(t *testing.T) {
 }
 
 func TestBuildFromSharedConfig(t *testing.T) {
-	env := stashEnv()
-	defer popEnv(env)
-	os.Setenv("AWS_SHARED_CONFIG_FILE", "file_not_exists")
-	os.Setenv("AWS_SHARED_CREDENTIALS_FILE", "file_not_exists")
+	oldEnv := initSessionTestEnv()
+	defer popEnv(oldEnv)
 
 	os.Setenv("AWS_SDK_LOAD_CONFIG", "0")
 	os.Setenv("AWS_SHARED_CREDENTIALS_FILE", testConfigFilename)
@@ -137,10 +131,8 @@ func TestBuildFromSharedConfig(t *testing.T) {
 func TestSessionAssumeRole_DisableSharedConfig(t *testing.T) {
 	// Backwards compatibility with Shared config disabled
 	// assume role should not be built into the config.
-	env := stashEnv()
-	defer popEnv(env)
-	os.Setenv("AWS_SHARED_CONFIG_FILE", "file_not_exists")
-	os.Setenv("AWS_SHARED_CREDENTIALS_FILE", "file_not_exists")
+	oldEnv := initSessionTestEnv()
+	defer popEnv(oldEnv)
 
 	os.Setenv("AWS_SDK_LOAD_CONFIG", "0")
 	os.Setenv("AWS_SHARED_CREDENTIALS_FILE", testConfigFilename)
@@ -157,10 +149,8 @@ func TestSessionAssumeRole_DisableSharedConfig(t *testing.T) {
 }
 
 func TestSesisonAssumeRole(t *testing.T) {
-	env := stashEnv()
-	defer popEnv(env)
-	os.Setenv("AWS_SHARED_CONFIG_FILE", "file_not_exists")
-	os.Setenv("AWS_SHARED_CREDENTIALS_FILE", "file_not_exists")
+	oldEnv := initSessionTestEnv()
+	defer popEnv(oldEnv)
 
 	os.Setenv("AWS_REGION", "us-east-1")
 	os.Setenv("AWS_SDK_LOAD_CONFIG", "1")
@@ -203,10 +193,8 @@ func TestSesisonAssumeRole(t *testing.T) {
 func TestSessionAssumeRole_InvalidSourceProfile(t *testing.T) {
 	// Backwards compatibility with Shared config disabled
 	// assume role should not be built into the config.
-	env := stashEnv()
-	defer popEnv(env)
-	os.Setenv("AWS_SHARED_CONFIG_FILE", "file_not_exists")
-	os.Setenv("AWS_SHARED_CREDENTIALS_FILE", "file_not_exists")
+	oldEnv := initSessionTestEnv()
+	defer popEnv(oldEnv)
 
 	os.Setenv("AWS_SDK_LOAD_CONFIG", "1")
 	os.Setenv("AWS_SHARED_CREDENTIALS_FILE", testConfigFilename)
@@ -260,7 +248,7 @@ func TestBuildFromSharedConfigProfile(t *testing.T) {
 			InEnvs: map[string]string{
 				"AWS_SDK_LOAD_CONFIG":         "0",
 				"AWS_SHARED_CREDENTIALS_FILE": testConfigFilename,
-				"AWS_SHARED_CONFIG_FILE":      testConfigOtherFilename,
+				"AWS_CONFIG_FILE":             testConfigOtherFilename,
 				"AWS_PROFILE":                 "shared_profile",
 			},
 			InProfile: "config_file_load_order",
@@ -274,10 +262,8 @@ func TestBuildFromSharedConfigProfile(t *testing.T) {
 	}
 
 	for _, c := range cases {
-		env := stashEnv()
-		defer popEnv(env)
-		os.Setenv("AWS_SHARED_CONFIG_FILE", "file_not_exists")
-		os.Setenv("AWS_SHARED_CREDENTIALS_FILE", "file_not_exists")
+		oldEnv := initSessionTestEnv()
+		defer popEnv(oldEnv)
 
 		for k, v := range c.InEnvs {
 			os.Setenv(k, v)
@@ -295,3 +281,34 @@ func TestBuildFromSharedConfigProfile(t *testing.T) {
 		assert.Contains(t, creds.ProviderName, c.OutCreds.ProviderName)
 	}
 }
+
+func TestNew_WithSessionLoadError(t *testing.T) {
+	oldEnv := initSessionTestEnv()
+	defer popEnv(oldEnv)
+
+	os.Setenv("AWS_SDK_LOAD_CONFIG", "1")
+	os.Setenv("AWS_CONFIG_FILE", testConfigFilename)
+	os.Setenv("AWS_PROFILE", "assume_role_invalid_source_profile")
+
+	s := New()
+
+	assert.NotNil(t, s)
+
+	svc := s3.New(s)
+	_, err := svc.ListBuckets(&s3.ListBucketsInput{})
+
+	assert.Error(t, err)
+	aerr := err.(awserr.Error)
+
+	assert.Equal(t, "SharedConfigLoadError", aerr.Code())
+	assert.Contains(t, aerr.Message(), "failed to create session")
+	assert.Contains(t, aerr.OrigErr().Error(), "SharedConfigAssumeRoleError")
+}
+
+func initSessionTestEnv() (oldEnv []string) {
+	oldEnv = stashEnv()
+	os.Setenv("AWS_CONFIG_FILE", "file_not_exists")
+	os.Setenv("AWS_SHARED_CREDENTIALS_FILE", "file_not_exists")
+
+	return oldEnv
+}