[lxc-devel] [lxd/master] main_forkdns: Restores usage output text when running with no arguments

[tomponline on Github]

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From a424fbfe3ac51c727ab6e1b7488fe15003d9abc1 Mon Sep 17 00:00:00 2001
From: Thomas Parrott <thomas.parrott at canonical.com>
Date: Wed, 12 Jun 2019 09:22:48 +0100
Subject: [PATCH 1/2] main_forkdns: Restores usage output text when running
 with no arguments

stgraber emphasised the use of the usage text when running the program here https://github.com/lxc/lxd/pull/5817#discussion_r291122104

This change restores access to it when running without any arguments.

Signed-off-by: Thomas Parrott <thomas.parrott at canonical.com>
---
 lxd/main_forkdns.go | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/lxd/main_forkdns.go b/lxd/main_forkdns.go
index 049d283a8b..e79d8ba77e 100644
--- a/lxd/main_forkdns.go
+++ b/lxd/main_forkdns.go
@@ -66,7 +66,13 @@ void forkdns()
 
 	close(STDIN_FILENO);
 
-	log_path = advance_arg(true);
+	log_path = advance_arg(false);
+	pid_path = advance_arg(false);
+
+	// If arguments are missing, fall through to Go part without double forking to output usage info.
+	if (log_path == NULL || pid_path == NULL)
+		return;
+
 	log_fd = open(log_path, O_WRONLY | O_CREAT | O_CLOEXEC | O_TRUNC, 0600);
 	if (log_fd < 0)
 		_exit(EXIT_FAILURE);
@@ -79,7 +85,6 @@ void forkdns()
 	if (ret < 0)
 		_exit(EXIT_FAILURE);
 
-	pid_path = advance_arg(true);
 	pid_file = fopen(pid_path, "we+");
 	if (!pid_file) {
 		fprintf(stderr,

From 5d374966e4fa28a5abd0bc6bfee5bbf73121117a Mon Sep 17 00:00:00 2001
From: Thomas Parrott <thomas.parrott at canonical.com>
Date: Wed, 12 Jun 2019 09:28:16 +0100
Subject: [PATCH 2/2] main_forkdns: Removes unused includes

Signed-off-by: Thomas Parrott <thomas.parrott at canonical.com>
---
 lxd/main_forkdns.go | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/lxd/main_forkdns.go b/lxd/main_forkdns.go
index e79d8ba77e..e339593c49 100644
--- a/lxd/main_forkdns.go
+++ b/lxd/main_forkdns.go
@@ -25,14 +25,9 @@ import (
 #include <errno.h>
 #include <fcntl.h>
 #include <stdbool.h>
-#include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <sys/epoll.h>
-#include <sys/socket.h>
-#include <sys/stat.h>
-#include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>