@@ -19383,6 +19383,10 @@ Scheduled Job Execution
This is a list of symbols naming Shepherd services that this service
will depend on.
+@item @code{instance} (type: maybe-symbol)
+Set the shepherd service name to @code{mcron-@var{instance}}. This is
+useful when you want to have more than one mcron instance.
+
@item @code{jobs} (default: @code{()}) (type: list-of-gexps)
This is a list of gexps (@pxref{G-Expressions}), where each gexp
corresponds to an mcron job specification (@pxref{Syntax, mcron job
@@ -19392,7 +19396,9 @@ Scheduled Job Execution
Log messages to standard output.
@item @code{log-file} (default: @code{"/var/log/mcron.log"}) (type: string)
-Log file location.
+Log file location. When @var{instance} is set and @var{log-file} is
+kept at its @emph{default value}, it will log to
+@file{/var/log/mcron-@var{instance}.log}.
@item @code{log-format} (default: @code{"~1@@*~a ~a: ~a~%"}) (type: string)
@code{(ice-9 format)} format string for log messages. The default value
@@ -19407,6 +19413,28 @@ Scheduled Job Execution
@end deftp
@c %end of fragment
+Occasionally, it is desirable to run another mcron instance to separate
+some of the jobs from the main mcron instance for clarity purposes, or if
+the jobs are very chatty and frequent. (for example, a heartbeat check
+every 30 seconds)
+
+The example below shows how an extra mcron service can be defined.
+@lisp
+(use (guix)
+ (guix records)
+ (gnu services)
+ (gnu services mcron))
+
+(define secondary-mcron-service-type
+ (service-type
+ (inherit mcron-service-type)
+ (name 'mcron-secondary)
+ (default-value
+ (mcron-configuration
+ (instance 'secondary)
+ (log-file "/var/log/mcron-secondary.log")))))
+@end lisp
+
@node Log Rotation
@subsection Log Rotation
@@ -27,12 +27,14 @@ (define-module (gnu services mcron)
#:use-module (guix records)
#:use-module (guix gexp)
#:use-module (srfi srfi-1)
+ #:use-module (ice-9 format)
#:use-module (ice-9 match)
#:use-module (ice-9 vlist)
#:export (mcron-configuration
mcron-configuration?
mcron-configuration-mcron
mcron-configuration-shepherd-requirement
+ mcron-configuration-instance
mcron-configuration-jobs
mcron-configuration-log?
mcron-configuration-log-file
@@ -63,6 +65,7 @@ (define list-of-symbols?
(list-of symbol?))
(define-maybe/no-serialization string)
+(define-maybe/no-serialization symbol)
(define-configuration/no-serialization mcron-configuration
(mcron
@@ -74,6 +77,11 @@ (define-configuration/no-serialization mcron-configuration
"This is a list of symbols naming Shepherd services that this service
will depend on.")
+ (instance
+ maybe-symbol
+ "Set the shepherd service name to @code{mcron-@var{instance}}.
+This is useful when you want to have more than one mcron instance.")
+
(jobs
(list-of-gexps '())
"This is a list of gexps (@pxref{G-Expressions}), where each gexp
@@ -86,7 +94,9 @@ (define-configuration/no-serialization mcron-configuration
(log-file
(string "/var/log/mcron.log")
- "Log file location.")
+ "Log file location. When @var{instance} is set and @var{log-file}
+is kept at its @emph{default value}, it will log to
+@file{/var/log/mcron-@var{instance}.log}.")
(log-format
(string "~1@*~a ~a: ~a~%")
@@ -167,12 +177,26 @@ (define (shepherd-schedule-action mcron files)
(define (mcron-shepherd-services config)
(match-record config <mcron-configuration>
- (mcron shepherd-requirement jobs log? log-file log-format date-format)
+ (mcron shepherd-requirement instance
+ jobs log? log-file log-format date-format)
(if (eq? jobs '())
'() ;nothing to do
- (let ((files (job-files mcron jobs)))
+ (let* ((files (job-files mcron jobs))
+ (instance-name
+ (format #f "mcron~@[-~a~]" (maybe-value instance)))
+ (service-name (string->symbol instance-name))
+ ;; Make log-file robust against multiple instances
+ ;; attempting to write to the same file when
+ ;; left at its default value.
+ (default-log-file (mcron-configuration-log-file
+ (mcron-configuration)))
+ (log-file* (if (and (maybe-value-set? instance)
+ (equal? log-file default-log-file))
+ (string-append (dirname default-log-file)
+ "/" instance-name ".log")
+ log-file)))
(list (shepherd-service
- (provision '(mcron))
+ (provision (list service-name))
(requirement `(user-processes ,@shepherd-requirement))
(modules `((srfi srfi-1)
(srfi srfi-26)
@@ -199,7 +223,7 @@ (define (mcron-shepherd-services config)
(remove (cut string-prefix? "PATH=" <>)
(environ)))
- #:log-file #$log-file))
+ #:log-file #$log-file*))
(stop #~(make-kill-destructor))
(actions
(list (shepherd-schedule-action mcron files)))))))))