[shepherd] 01/06: log-rotation: Add ‘files’ action.

[Ludovic Courtès]

civodul pushed a commit to branch devel
in repository shepherd.

commit 2f30e81ebb4855788ce7c138c0a3a6466d60cc10
Author: Ludovic Courtès <ludo@gnu.org>
AuthorDate: Wed Jun 12 17:21:30 2024 +0200

    log-rotation: Add ‘files’ action.
    
    * modules/shepherd/service/log-rotation.scm (log-rotation-service)
    [action]: Rename to…
    [rotation]: … this.
    [files-action]: New variable.
    Add it to #:actions.
    * tests/services/log-rotation.sh: Test it.
    * doc/shepherd.texi (Log Rotation Service): Document it.
---
 doc/shepherd.texi                         |  6 ++++++
 modules/shepherd/service/log-rotation.scm | 30 ++++++++++++++++++++++++++----
 tests/services/log-rotation.sh            |  5 +++++
 3 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/doc/shepherd.texi b/doc/shepherd.texi
index 595b69e..2a59899 100644
--- a/doc/shepherd.texi
+++ b/doc/shepherd.texi
@@ -1981,6 +1981,12 @@ You can also trigger it explicitly at any time, like so:
 herd trigger log-rotation
 @end example
 
+Last, you can list log files subject to rotation:
+
+@example
+herd files log-rotation
+@end example
+
 The default settings should be good for most use cases, but you can
 change them by passing the @code{log-rotation-service} procedure a
 number of arguments---see the reference documentation below.
diff --git a/modules/shepherd/service/log-rotation.scm 
b/modules/shepherd/service/log-rotation.scm
index 0145b9a..66721ad 100644
--- a/modules/shepherd/service/log-rotation.scm
+++ b/modules/shepherd/service/log-rotation.scm
@@ -25,7 +25,9 @@
                                          timer-trigger-action)
   #:autoload   (shepherd service) (service
                                    service-logger
-                                   for-each-service)
+                                   service-canonical-name
+                                   for-each-service
+                                   action)
   #:autoload   (shepherd system) (%gzip-program %zstd-program)
   #:use-module (srfi srfi-1)
   #:use-module (srfi srfi-26)
@@ -248,7 +250,7 @@ only if the service that mounts the file system that hosts 
log files is up."
             (local-output (l10n "Deleting old log file '~a'.") old)
             (delete-file old)))))
 
-  (define action
+  (define rotation
     (lambda ()
       (rotate-service-logs rotate
                            #:compression compression
@@ -262,9 +264,29 @@ only if the service that mounts the file system that hosts 
log files is up."
                                        rotation-size-threshold))
                 external-log-files)))
 
+  (define files-action
+    (action 'files
+            (lambda _
+              (for-each-service (lambda (service)
+                                  (match (service-logger service)
+                                    (#f #f)
+                                    (logger
+                                     (let ((file (logger-file logger)))
+                                       (when file
+                                         (format #t "~a\t~a~%"
+                                                 file (service-canonical-name
+                                                       service))))))))
+              (for-each (lambda (file)
+                          ;; TRANSLATORS: "External" here refers to "external
+                          ;; log files".
+                          (format #t (l10n "~a\t(external)~%")
+                                  file))
+                        external-log-files))
+            (l10n "List the log files subject to rotation.")))
+
   (service provision
-           #:start (make-timer-constructor event action)
+           #:start (make-timer-constructor event rotation)
            #:stop (make-timer-destructor)
-           #:actions (list timer-trigger-action)
+           #:actions (list timer-trigger-action files-action)
            #:documentation
            (l10n "Periodically rotate the log files of services.")))
diff --git a/tests/services/log-rotation.sh b/tests/services/log-rotation.sh
index 15e3e9e..62f2b7b 100644
--- a/tests/services/log-rotation.sh
+++ b/tests/services/log-rotation.sh
@@ -70,6 +70,11 @@ $herd start log-rotation
 
 sleep 0.5
 
+for file in "$service_log1" "$service_log2" "$external_log"
+do
+    $herd files log-rotation | grep "$file"
+done
+
 test -f "$service_log1"
 test -f "$service_log2"
 echo "This is an external log file." > "$external_log"