[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Shepherd redirect stdout/stderr to syslog
From: |
David Craven |
Subject: |
Re: Shepherd redirect stdout/stderr to syslog |
Date: |
Mon, 5 Sep 2016 15:44:40 +0200 |
> Is redirecting stdout/stderr to syslog something that
> make-forkexec-constructor could/should do?
I looked into what would be involved. I included a diff that I didn't
test and don't expect to work.
The reason why I don't expect this to work is that running echo
"hello" > /dev/log errors. stracing logger "hello" shows that it makes
use of the socket and sendmsg syscalls instead of the usual open and
write syscalls. I don't understand why though, since what's the point
of everything being a file if they don't share the same interface?
diff --git a/modules/shepherd/service.scm b/modules/shepherd/service.scm
index 49f6e8b..69c1cc2 100644
--- a/modules/shepherd/service.scm
+++ b/modules/shepherd/service.scm
@@ -712,12 +712,18 @@ false."
;; Close all the file descriptors except stdout and stderr.
(let ((max-fd (max-file-descriptors)))
+ ;; Redirect stdin to use /dev/null
(catch-system-error (close-fdes 0))
-
;; Make sure file descriptor zero is used, so we don't end up reusing
;; it for something unrelated, which can confuse some packages.
(dup2 (open-fdes "/dev/null" O_RDONLY) 0)
+ ;; Redirect stout and stderr to use /dev/log
+ (catch-system-error (close-fdes 1))
+ (catch-system-error (close-fdes 2))
+ (dup2 (open-fdes "/dev/log" O_WRONLY) 1)
+ (dup2 (open-fdes "/dev/log" O_WRONLY) 2)
+
(let loop ((i 3))
(when (< i max-fd)
(catch-system-error (close-fdes i))