node rejoin: improve error code handling

- return ERR_REJOIN_FAIL in all cases where the rejoin operation fails
 - ensure ERR_FOLLOW_FAIL is not returned
 - document error codes

doc/repmgr-node-check.sgml

@@ -165,6 +165,7 @@
       Following exit codes can be emitted by <command>repmgr status check</command>
       if no individual check was specified.
     </para>
+
     <variablelist>
 
       <varlistentry>
@@ -186,6 +187,7 @@
       </varlistentry>
 
    </variablelist>
+
   </refsect1>
 
 

doc/repmgr-node-rejoin.sgml

@@ -255,6 +255,59 @@
 
   </refsect1>
 
+  <refsect1>
+    <title>Exit codes</title>
+    <para>
+      Following exit codes can be emitted by <command>repmgr node rejoin</command>:
+    </para>
+
+    <variablelist>
+
+      <varlistentry>
+        <term><option>SUCCESS (0)</option></term>
+        <listitem>
+          <para>
+            The node rejoin succeeded; or if <option>--dry-run</option> was provided,
+            no issues were detected which would prevent the node rejoin.
+          </para>
+        </listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>ERR_BAD_CONFIG (1)</option></term>
+        <listitem>
+          <para>
+            A configuration issue was detected which prevented &repmgr; from
+            continuing with the node rejoin.
+          </para>
+        </listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>ERR_NO_RESTART (4)</option></term>
+        <listitem>
+          <para>
+            The node could not be restarted.
+          </para>
+        </listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>ERR_REJOIN_FAIL (24)</option></term>
+        <listitem>
+          <para>
+            The node rejoin operation failed.
+          </para>
+        </listitem>
+      </varlistentry>
+
+
+    </variablelist>
+
+  </refsect1>
+
+  </refsect1>
+
   <refsect1>
     <title>See also</title>
     <para>

repmgr-action-node.c

@@ -2174,7 +2174,7 @@ do_node_rejoin(void)
 		log_error(_("database is still running in state \"%s\""),
 				  describe_db_state(db_state));
 		log_hint(_("\"repmgr node rejoin\" cannot be executed on a running node"));
-		exit(ERR_BAD_CONFIG);
+		exit(ERR_REJOIN_FAIL);
 	}
 
 	/* check if cleanly shut down */
@@ -2193,7 +2193,7 @@ do_node_rejoin(void)
 				log_detail(_("pg_rewind will not be able to run"));
 			}
 			log_hint(_("database should be restarted then shut down cleanly after crash recovery completes"));
-			exit(ERR_BAD_CONFIG);
+			exit(ERR_REJOIN_FAIL);
 		}
 	}
 
@@ -2255,7 +2255,7 @@ do_node_rejoin(void)
 		if (can_follow == false)
 		{
 			PQfinish(upstream_conn);
-			exit(ERR_BAD_CONFIG);
+			exit(ERR_REJOIN_FAIL);
 		}
 	}
 
@@ -2358,7 +2358,7 @@ do_node_rejoin(void)
 
 				termPQExpBuffer(&command_output);
 
-				exit(ERR_BAD_CONFIG);
+				exit(ERR_REJOIN_FAIL);
 			}
 
 			termPQExpBuffer(&command_output);
@@ -2471,6 +2471,7 @@ do_node_rejoin(void)
 										 upstream_conn,
 										 &primary_node_record,
 										 &follow_output,
+										 ERR_REJOIN_FAIL,
 										 &follow_error_code);
 
 	if (success == false)

repmgr-action-standby.c

@@ -2561,6 +2561,7 @@ do_standby_follow(void)
 		follow_target_conn,
 		&follow_target_node_record,
 		&follow_output,
+		ERR_FOLLOW_FAIL,
 		&follow_error_code);
 
 	/* unable to restart the standby */
@@ -2665,7 +2666,7 @@ do_standby_follow(void)
  * this function.
  */
 bool
-do_standby_follow_internal(PGconn *primary_conn, PGconn *follow_target_conn, t_node_info *follow_target_node_record, PQExpBufferData *output, int *error_code)
+do_standby_follow_internal(PGconn *primary_conn, PGconn *follow_target_conn, t_node_info *follow_target_node_record, PQExpBufferData *output, int general_error_code, int *error_code)
 {
 	t_node_info local_node_record = T_NODE_INFO_INITIALIZER;
 	int			original_upstream_node_id = UNKNOWN_NODE_ID;
@@ -2691,7 +2692,7 @@ do_standby_follow_internal(PGconn *primary_conn, PGconn *follow_target_conn, t_n
 		log_error(_("unable to retrieve record for node %i"),
 				  config_file_options.node_id);
 
-		*error_code = ERR_FOLLOW_FAIL;
+		*error_code = ERR_BAD_CONFIG;
 		return false;
 	}
 
@@ -2818,7 +2819,7 @@ do_standby_follow_internal(PGconn *primary_conn, PGconn *follow_target_conn, t_n
 
 	if (!create_recovery_file(&local_node_record, &recovery_conninfo, config_file_options.data_directory, true))
 	{
-		*error_code = ERR_FOLLOW_FAIL;
+		*error_code = general_error_code;
 		return false;
 	}
 
@@ -2969,7 +2970,6 @@ do_standby_follow_internal(PGconn *primary_conn, PGconn *follow_target_conn, t_n
 		return false;
 	}
 
-
 	appendPQExpBuffer(output,
 					  _("node %i is now attached to node %i"),
 					  config_file_options.node_id,

repmgr-action-standby.h

@@ -28,7 +28,7 @@ extern void do_standby_switchover(void);
 
 extern void do_standby_help(void);
 
-extern bool do_standby_follow_internal(PGconn *primary_conn, PGconn *follow_target_conn, t_node_info *follow_target_node_record, PQExpBufferData *output, int *error_code);
+extern bool do_standby_follow_internal(PGconn *primary_conn, PGconn *follow_target_conn, t_node_info *follow_target_node_record, PQExpBufferData *output, int general_error_code, int *error_code);