aws/external: Add example for shared config and static credential helper

aws/external/example_test.go

@@ -0,0 +1,60 @@
+package external_test
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/aws/aws-sdk-go-v2/aws"
+	"github.com/aws/aws-sdk-go-v2/aws/external"
+)
+
+func ExampleWithSharedConfigProfile() {
+	cfg, err := external.LoadDefaultAWSConfig(
+		// Specify the shared configuration profile to load.
+		external.WithSharedConfigProfile("exampleProfile"),
+
+		// Optionally specify the specific shared configuraiton
+		// files to load the profile from.
+		external.WithSharedConfigFiles([]string{
+			filepath.Join("testdata", "shared_config"),
+		}),
+	)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "failed to load config, %v", err)
+		os.Exit(1)
+	}
+
+	// Region loaded from credentials file.
+	fmt.Println("Region:", cfg.Region)
+
+	// Output:
+	// Region: us-west-2
+}
+
+func ExampleWithCredentialsValue() {
+	cfg, err := external.LoadDefaultAWSConfig(
+		// Hard coded credentials.
+		external.WithCredentialsValue(aws.Credentials{
+			AccessKeyID: "AKID", SecretAccessKey: "SECRET", SessionToken: "SESSION",
+			Source: "example hard coded credentials",
+		}),
+	)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "failed to load config, %v", err)
+		os.Exit(1)
+	}
+
+	// Credentials retrieve will be called automatically internally to the SDK
+	// service clients created with the cfg value.
+	creds, err := cfg.Credentials.Retrieve()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "failed to get credentials, %v", err)
+		os.Exit(1)
+	}
+
+	fmt.Println("Credentials Source:", creds.Source)
+
+	// Output:
+	// Credentials Source: example hard coded credentials
+}

aws/external/testdata/shared_config

@@ -5,6 +5,11 @@ s3 =
 
 region = default_region
 
+[profile exampleProfile]
+region = us-west-2
+aws_access_key_id = AKID
+aws_secret_access_key = SECRET
+
 [profile alt_profile_name]
 region = alt_profile_name_region