chore(gssapi): refine schema doc

apps/emqx_auth_gssapi/src/emqx_authn_gssapi_schema.erl

@@ -42,12 +42,12 @@ fields(gssapi) ->
             {principal,
                 ?HOCON(binary(), #{
                     required => true,
-                    desc => ?DESC(emqx_bridge_kafka, auth_kerberos_principal)
+                    desc => ?DESC(principal)
                 })},
             {keytab_file,
                 ?HOCON(binary(), #{
                     required => true,
-                    desc => ?DESC(emqx_bridge_kafka, auth_kerberos_keytab_file)
+                    desc => ?DESC(keytab_file)
                 })}
         ].
 

rel/i18n/emqx_authn_gssapi_schema.hocon

@@ -0,0 +1,18 @@
+emqx_authn_gssapi_schema {
+
+principal {
+    label: "Kerberos Principal"
+    desc: """~
+        SASL GSSAPI authentication Kerberos principal.
+        For example <code>mqtt/node1.example.com@MY_REALM.EXAMPLE.COM</code>.
+        NOTE: The realm in use has to be configured in /etc/krb5.conf in EMQX nodes.~"""
+}
+
+keytab_file {
+    label: "keytab file"
+    desc: """~
+        SASL GSSAPI authentication Kerberos keytab file path.
+        NOTE: This file has to be placed in EMQX nodes.~"""
+}
+
+}

rel/i18n/emqx_bridge_kafka.hocon

@@ -147,7 +147,7 @@ consumer_mqtt_opts.label:
 """MQTT publish"""
 
 auth_kerberos_principal.desc:
-"""SASL GSSAPI authentication Kerberos principal. For example <code>client_name@MY.KERBEROS.REALM.MYDOMAIN.COM</code>, NOTE: The realm in use has to be configured in /etc/krb5.conf in EMQX nodes."""
+"""SASL GSSAPI authentication Kerberos principal. For example <code>kafka/node1.example.com@EXAMPLE.COM</code>, NOTE: The realm in use has to be configured in /etc/krb5.conf in EMQX nodes."""
 
 auth_kerberos_principal.label:
 """Kerberos Principal"""