Improve GetAWSContainer error handling

Author: gtsiolis

README.md

@@ -83,6 +83,14 @@ To see which config file is currently in use:
 lstk config path
 ```
 
+You can also configure AWS CLI integration:
+
+```bash
+lstk setup aws
+```
+
+This sets up a `localstack` profile in `~/.aws/config` and `~/.aws/credentials`.
+
 You can also point `lstk` at a specific config file for any command:
 
 ```bash
@@ -184,6 +192,9 @@ lstk update
 # Show resolved config file path
 lstk config path
 
+# Set up AWS CLI profile integration
+lstk setup aws
+
 ```
 
 ## Reporting bugs

internal/config/containers.go

@@ -140,12 +140,12 @@ func (c *ContainerConfig) ProductName() (string, error) {
 }
 
 // GetAWSContainer returns the AWS container config from the list of containers.
-// Returns nil if no AWS container is configured.
-func GetAWSContainer(containers []ContainerConfig) *ContainerConfig {
+// Returns an error if no AWS container is configured.
+func GetAWSContainer(containers []ContainerConfig) (*ContainerConfig, error) {
 	for i := range containers {
 		if containers[i].Type == EmulatorAWS {
-			return &containers[i]
+			return &containers[i], nil
 		}
 	}
-	return nil
+	return nil, fmt.Errorf("no aws emulator configured")
 }

internal/ui/run_awsconfig.go

@@ -2,7 +2,6 @@ package ui
 
 import (
 	"context"
-	"fmt"
 
 	"github.com/localstack/lstk/internal/awsconfig"
 	"github.com/localstack/lstk/internal/config"
@@ -13,9 +12,9 @@ import (
 // RunConfigProfile runs the AWS profile setup flow with TUI output.
 // It resolves the host from the AWS container config and runs the setup.
 func RunConfigProfile(parentCtx context.Context, containers []config.ContainerConfig, localStackHost string) error {
-	awsContainer := config.GetAWSContainer(containers)
-	if awsContainer == nil {
-		return fmt.Errorf("no aws emulator configured")
+	awsContainer, err := config.GetAWSContainer(containers)
+	if err != nil {
+		return err
 	}
 
 	resolvedHost, dnsOK := endpoint.ResolveHost(awsContainer.Port, localStackHost)

test/integration/awsconfig_test.go

@@ -134,7 +134,8 @@ func TestStartSkipsAWSProfilePromptWhenAlreadyConfigured(t *testing.T) {
 	_ = cmd.Process.Kill()
 	err = cmd.Wait()
 	<-outputCh
-	require.NoError(t, err, "lstk start should exit after kill")
+	// Process was killed, so we expect an error from Wait()
+	require.Error(t, err, "lstk start should exit after kill")
 
 	assert.NotContains(t, out.String(), awsSetupPrompt,
 		"profile prompt should not appear when profile is already correctly configured")