[bug#54309] [PATCH] services: auditd: use exclusive log directory for auditd

[fesoj000 <fesoj000@gmail.com>]

Use /var/log/audit for auditd. This is the upstream default.

Further, make the inline config file more readable.

* gnu/services/auditd.scm: add auditd-activation function and extend
activation-service-type.
---
  gnu/services/auditd.scm | 27 ++++++++++++++++++++++-----
  1 file changed, 22 insertions(+), 5 deletions(-)

diff --git a/gnu/services/auditd.scm b/gnu/services/auditd.scm
index abde811f51..e9e19c61be 100644
--- a/gnu/services/auditd.scm
+++ b/gnu/services/auditd.scm
@@ -31,10 +31,15 @@ (define-module (gnu services auditd)
              %default-auditd-configuration-directory))
  
  (define auditd.conf
-  (plain-file "auditd.conf" "log_file = /var/log/audit.log\nlog_format = \
-ENRICHED\nfreq = 1\nspace_left = 5%\nspace_left_action = \
-syslog\nadmin_space_left_action = ignore\ndisk_full_action = \
-ignore\ndisk_error_action = syslog\n"))
+  (plain-file "auditd.conf" "\
+log_format = ENRICHED
+freq = 1
+space_left = 5%
+space_left_action = syslog
+admin_space_left_action = ignore
+disk_full_action = ignore
+disk_error_action = syslog
+"))
  
  (define %default-auditd-configuration-directory
    (computed-file "auditd"
@@ -50,6 +55,16 @@ (define-record-type* <auditd-configuration>
                             (default audit))
    (configuration-directory auditd-configuration-configuration-directory))      ; file-like
  
+(define (auditd-activation config)
+  (with-imported-modules '((guix build utils))
+    #~(begin
+        (use-modules (guix build utils))
+        ;; make sure /var/log exists before changing umask
+        (mkdir-p "/var/log")
+        (let* ((previous-umask (umask #o077)))
+          (mkdir-p "/var/log/audit")
+          (umask previous-umask)))))
+
  (define (auditd-shepherd-service config)
    (let* ((audit (auditd-configuration-audit config))
           (configuration-directory (auditd-configuration-configuration-directory config)))
@@ -67,7 +82,9 @@ (define auditd-service-type
                  (extensions
                   (list
                    (service-extension shepherd-root-service-type
-                                     auditd-shepherd-service)))
+                                     auditd-shepherd-service)
+                  (service-extension activation-service-type
+                                     auditd-activation)))
                  (default-value
                    (auditd-configuration
                     (configuration-directory %default-auditd-configuration-directory)))))
-- 
2.34.0