branch: main
commit fc0e5e1bc0805ccf6dab2b943220e6fe2c843f83
Author: Ludovic Courtès <[email protected]>
AuthorDate: Fri Mar 21 17:28:40 2025 +0100
register: Support socket activation.
* src/cuirass/scripts/register.scm (listening-sockets): New procedure.
(cuirass-register): Use it.
* doc/cuirass.texi (Invocation): Document it.
---
doc/cuirass.texi | 22 +++++++++++++++++++++-
src/cuirass/scripts/register.scm | 24 +++++++++++++++++++++---
2 files changed, 42 insertions(+), 4 deletions(-)
diff --git a/doc/cuirass.texi b/doc/cuirass.texi
index f832c76..04f91f2 100644
--- a/doc/cuirass.texi
+++ b/doc/cuirass.texi
@@ -507,7 +507,27 @@ cuirass register --specifications @var{specs}
This starts a Cuirass registration instance building @var{specs} and
storing the results using the default PostgreSQL database.
-Additionally the following options can be used.
+@cindex socket activation
+Alternatively, the @command{cuirass register} process can be
+@dfn{socket-activated} (@pxref{Service De- and Constructors,
+@code{make-system-constructor},, shepherd, The GNU Shepherd Manual}).
+In that case, the service manager (which could be the Shepherd or
+systemd) must provide it with two open stream-oriented sockets:
+
+@itemize @code
+@item bridge
+this socket allows other Cuirass process to communicate with this one
+and should be bound to @file{/var/run/cuirass/bridge};
+@item remote-builds
+this is the socket @command{cuirass remote-server} connects to should be
+bound to @file{/var/run/cuirass/remote-builds}.
+@end itemize
+
+Using the socket activation mechanism ensures proper synchronization
+among the various @command{cuirass} process when they start up.
+
+The full list of options @command{cuirass register} supports is given
+below.
@table @code
@item --one-shot
diff --git a/src/cuirass/scripts/register.scm b/src/cuirass/scripts/register.scm
index 836dfe4..a71d2ff 100644
--- a/src/cuirass/scripts/register.scm
+++ b/src/cuirass/scripts/register.scm
@@ -105,6 +105,24 @@
(log-info "opening bridge socket at '~a'" (%bridge-socket-file-name))
(open-unix-listening-socket (%bridge-socket-file-name)))
+(define (listening-sockets)
+ "Return a list of name/port pairs corresponding to each server socket
+accepting incoming connections."
+ (match (activation-sockets)
+ (()
+ ;; Not socket-activated so explicitly open these sockets.
+ `((bridge . ,(open-bridge-socket))
+ (remote-builds . ,(open-unix-listening-socket
+ (%remote-server-socket-file-name)))))
+ (lst
+ (log-info "socket-activated with the following sockets:~{ ~a~}"
+ (map car lst))
+ (unless (and (assoc-ref lst 'bridge)
+ (assoc-ref lst 'remote-builds))
+ (log-error "missing some sockets")
+ (exit 1))
+ lst)))
+
(define (bridge channel ;currently unused
socket registry)
(define (serve-client socket)
@@ -272,10 +290,10 @@
(leave (G_ "'--one-shot' is currently unimplemented~%"))
(let* ((exit-channel (make-channel))
(event-log-service (spawn-event-log-service))
+ (sockets (listening-sockets))
(builder (if (option-ref opts 'build-remote #f)
(spawn-remote-builder
- (open-unix-listening-socket
- (%remote-server-socket-file-name))
+ (assoc-ref sockets 'remote-builds)
event-log-service)
(spawn-local-builder
event-log-service)))
(evaluator (spawn-jobset-evaluator
@@ -310,7 +328,7 @@
;; Spawn the bridge through which other 'cuirass'
;; processes, such as 'cuirass web', may talk to the
;; registry.
- (spawn-bridge (open-bridge-socket) registry))
+ (spawn-bridge (assoc-ref sockets 'bridge) registry))
;; Periodically delete old GC roots.
(spawn-gc-root-cleaner gc-root-ttl
