add credential string constants, ValidCredentials and ValidCredentialsString methods

Author: sfomuseumbot

config.go

@@ -3,10 +3,11 @@ package auth
 import (
 	"context"
 	"fmt"
+	"log/slog"
 	"net/url"
 	"os/user"
 	"path/filepath"
-	"sort"
+	_ "sort"
 	"strings"
 
 	"github.com/aws/aws-sdk-go-v2/aws"
@@ -17,20 +18,49 @@ import (
 // null_cfg is a placeholder to return in error contexts.
 var null_cfg aws.Config
 
-// CredentialsStringPatterns() returns the list of valid credential strings patterns.
-func CredentialsStringPatterns() []string {
+const AnonymousCredentialsString string = "anon:"
+
+const EnvironmentCredentialsString string = "env:"
+
+const IAMCredentialsString string = "iam:"
+
+const ProfileCredentialsTemplate string = "{profile}"
+
+const ProfileFromPathCredentialsTemplate string = "{path}:{profile}"
+
+const StaticCredentialsTemplate string = "static:{id}:{key}:{secret}"
+
+const StaticCredentialsPrefix string = "static:"
+
+const STSCredentialsPrefix string = "sts:"
 
-	patterns := []string{
-		"anon:",
-		"env:",
-		"iam:",
-		"{PROFILE}",
-		"{PATH}:{PROFILE}",
-		"static:{KEY}:{SECRET}:{TOKEN}",
+// ValidCredentials() returns the list of valid credential strings patterns.
+func ValidCredentials() []string {
+
+	valid := []string{
+		AnonymousCredentialsString,
+		EnvironmentCredentialsString,
+		IAMCredentialsString,
+		STSCredentialsPrefix,
+		ProfileCredentialsTemplate,
+		ProfileFromPathCredentialsTemplate,
+		StaticCredentialsTemplate,
 	}
 
-	sort.Strings(patterns)
-	return patterns
+	return valid
+}
+
+func ValidCredentialsString() string {
+
+	valid := ValidCredentials()
+
+	return fmt.Sprintf("Valid credential flags are: %s", strings.Join(valid, ", "))
+}
+
+// CredentialsStringPatterns() returns the list of valid credential strings patterns. DEPRECATED. Please use `ValidCredentials` instead.
+func CredentialsStringPatterns() []string {
+	slog.Warn("CredentialsStringPatterns() is deprecated. Please call ValidCredentials() instead.")
+	return ValidCredentials()
 }
 
 // NewConfig() returns a new `aws.Config` derived from 'uri' which is expected to be configured