02/03: services: web: 'static-web-site-configuration' can specify an update period.

[Ludovic Courtès]

civodul pushed a commit to branch master
in repository maintenance.

commit bdb914a1242cb0c00957050c96d1e279d2eb5dec
Author: Ludovic Courtès <ludo@gnu.org>
AuthorDate: Thu Oct 28 17:13:20 2021 +0200

    services: web: 'static-web-site-configuration' can specify an update period.
    
    * hydra/modules/sysadmin/web.scm (<static-web-site-configuration>)[period]:
    New field.
    (static-web-site-mcron-jobs): Honor it.
---
 hydra/modules/sysadmin/web.scm | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/hydra/modules/sysadmin/web.scm b/hydra/modules/sysadmin/web.scm
index abac188..a3d1ce3 100644
--- a/hydra/modules/sysadmin/web.scm
+++ b/hydra/modules/sysadmin/web.scm
@@ -131,6 +131,8 @@ that's built with Haunt or similar."
                (default '(branch . "master")))
   (build-file  static-web-site-configuration-build-file
                (default "guix.scm"))
+  (period      static-web-site-configuration-period
+               (default 3600))                    ;seconds
   (environment-variables static-web-site-configuration-environment-variable
                          (default '()))
   (cache-directory static-web-site-configuration-cache-directory
@@ -153,9 +155,14 @@ that's built with Haunt or similar."
                            (basename
                             (static-web-site-configuration-directory 
config)))))
 
-  ;; Spread web site updates over the hour to avoid I/O load peaks.
-  (let ((minutes (hash (static-web-site-configuration-git-url config) 60)))
-    (list #~(job '(next-minute '(#$minutes)) #$update
+  ;; Add an offset to spread web site updates over the period to avoid I/O
+  ;; load peaks when there are several such jobs.
+  (let* ((period (static-web-site-configuration-period config))
+         (offset (hash config period)))
+    (list #~(job (lambda (now)
+                   (let ((elapsed (modulo now #$period)))
+                     (+ now (- #$period elapsed) #$offset)))
+                 #$update
                  #:user "static-web-site"))))
 
 (define (static-web-site-activation config)