util: log available configs when KMS not found

When the KMS configuration can not be found, it is useful to know what
configurations are available. This aids troubleshooting when typos in
the KMS ID are made.

Signed-off-by: Niels de Vos <ndevos@redhat.com>

internal/util/kms.go

@@ -67,7 +67,7 @@ func GetKMS(tenant, kmsID string, secrets map[string]string) (EncryptionKMS, err
 	section, ok := config[kmsID]
 	if !ok {
 		return nil, fmt.Errorf("could not get KMS configuration "+
-			"for %q", kmsID)
+			"for %q (have %v)", kmsID, getKeys(config))
 	}
 
 	// kmsConfig can have additional sub-sections

internal/util/util.go

@@ -319,3 +319,17 @@ func contains(s []string, key string) bool {
 
 	return false
 }
+
+// getKeys takes a map that uses strings for keys and returns a slice with the
+// keys.
+func getKeys(m map[string]interface{}) []string {
+	keys := make([]string, len(m))
+
+	i := 0
+	for k := range m {
+		keys[i] = k
+		i++
+	}
+
+	return keys
+}