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authorLudovic Courtès <ludo@gnu.org>2022-03-30 16:10:18 +0200
committerLudovic Courtès <ludo@gnu.org>2022-04-07 00:08:55 +0200
commit938448bf40fc77092859352d2243e2d0c236375f (patch)
treeede2c89968aa48d4e61c3249cba83437af4ed57c /gnu/build/shepherd.scm
parentd4172babe0f54c69a1203ce05e719e9021e26110 (diff)
shepherd: Adjust 'fork+exec-command/container' for the Shepherd 0.9.
* gnu/build/shepherd.scm (exec-command*): New procedure, with code formerly... (make-forkexec-constructor/container): ... here. Use it. (fork+exec-command/container): Use 'fork+exec-command' only when CONTAINER-SUPPORT? is false or PID is the current process.
Diffstat (limited to 'gnu/build/shepherd.scm')
-rw-r--r--gnu/build/shepherd.scm83
1 files changed, 54 insertions, 29 deletions
diff --git a/gnu/build/shepherd.scm b/gnu/build/shepherd.scm
index 778e3fc627..0627bac5b9 100644
--- a/gnu/build/shepherd.scm
+++ b/gnu/build/shepherd.scm
@@ -1,5 +1,5 @@
;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2017, 2018, 2019, 2020 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2017, 2018, 2019, 2020, 2022 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2020 Mathieu Othacehe <othacehe@gnu.org>
;;;
;;; This file is part of GNU Guix.
@@ -103,8 +103,13 @@
separate mount and PID name space. Return the \"outer\" PID. "
(match (container-excursion* pid
(lambda ()
- (read-pid-file pid-file
- #:max-delay max-delay)))
+ ;; XXX: Trick for Shepherd 0.9: prevent 'read-pid-file' from
+ ;; using (@ (fibers) sleep), which would try to suspend the
+ ;; current task, which doesn't work in this extra process.
+ (with-continuation-barrier
+ (lambda ()
+ (read-pid-file pid-file
+ #:max-delay max-delay)))))
(#f
;; Send SIGTERM to the whole process group.
(catch-system-error (kill (- pid) SIGTERM))
@@ -114,6 +119,26 @@ separate mount and PID name space. Return the \"outer\" PID. "
;; PID is always 1, but that's not what Shepherd needs to know.
pid)))
+(define* (exec-command* command #:key user group log-file pid-file
+ directory (environment-variables (environ)))
+ "Like 'exec-command', but first restore signal handles modified by
+shepherd (PID 1)."
+ ;; First restore the default handlers.
+ (for-each (cut sigaction <> SIG_DFL) %precious-signals)
+
+ ;; Unblock any signals that have been blocked by the parent process.
+ (unblock-signals %precious-signals)
+
+ (mkdir-p "/var/run")
+ (clean-up pid-file)
+
+ (exec-command command
+ #:user user
+ #:group group
+ #:log-file log-file
+ #:directory directory
+ #:environment-variables environment-variables))
+
(define* (make-forkexec-constructor/container command
#:key
(namespaces
@@ -164,24 +189,14 @@ namespace, in addition to essential bind-mounts such /proc."
(let ((pid (run-container container-directory
mounts namespaces 1
(lambda ()
- ;; First restore the default handlers.
- (for-each (cut sigaction <> SIG_DFL)
- %precious-signals)
-
- ;; Unblock any signals that have been blocked
- ;; by the parent process.
- (unblock-signals %precious-signals)
-
- (mkdir-p "/var/run")
- (clean-up pid-file)
-
- (exec-command command
- #:user user
- #:group group
- #:log-file log-file
- #:directory directory
- #:environment-variables
- environment-variables)))))
+ (exec-command* command
+ #:user user
+ #:group group
+ #:pid-file pid-file
+ #:log-file log-file
+ #:directory directory
+ #:environment-variables
+ environment-variables)))))
(if pid-file
(if (or (memq 'mnt namespaces) (memq 'pid namespaces))
(read-pid-file/container pid pid-file
@@ -209,14 +224,24 @@ on Hurd systems for instance, fallback to direct forking."
((head . rest)
(loop rest (cons head result))))))
- (let ((container-support?
- (file-exists? "/proc/self/ns"))
- (fork-proc (lambda ()
- (apply fork+exec-command command
- (strip-pid args)))))
- (if container-support?
- (container-excursion* pid fork-proc)
- (fork-proc))))
+ (let ((container-support? (file-exists? "/proc/self/ns")))
+ (if (and container-support?
+ (not (and pid (= pid (getpid)))))
+ (container-excursion* pid
+ (lambda ()
+ ;; Note: In the Shepherd 0.9, 'fork+exec-command' expects to be
+ ;; called from the shepherd process (because it creates a pipe to
+ ;; capture stdout/stderr and spawns a logging fiber) so we cannot
+ ;; use it here.
+ (match (primitive-fork)
+ (0 (dynamic-wind
+ (const #t)
+ (lambda ()
+ (apply exec-command* command (strip-pid args)))
+ (lambda ()
+ (primitive-_exit 127))))
+ (pid #t))))
+ (apply fork+exec-command command (strip-pid args)))))
;; Local Variables:
;; eval: (put 'container-excursion* 'scheme-indent-function 1)