[bug#61789] [PATCH 10/27] services: base: Deprecate 'pam-limits-service' procedure.

[Bruno Victal <mirai@makinata.eu>]

* doc/guix.texi (Base Services): Replace pam-limits-service with pam-limits-service-type.
* gnu/packages/benchmark.scm (python-locust)[description]: Update index anchor to manual.
* gnu/services/base.scm (pam-limits-service-type): Accept both lists and
file-like objects for compatibility.
(pam-limits-service): Deprecate procedure.
---
 doc/guix.texi              | 18 ++++++++---------
 gnu/packages/benchmark.scm |  2 +-
 gnu/services/base.scm      | 41 +++++++++++++++++++++++++++-----------
 3 files changed, 39 insertions(+), 22 deletions(-)

diff --git a/doc/guix.texi b/doc/guix.texi
index ec6f2d9c31..f9ca809e47 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -18938,7 +18938,6 @@ Base Services
 @end table
 @end deftp
 
-@anchor{pam-limits-service}
 @cindex session limits
 @cindex ulimit
 @cindex priority
@@ -18946,19 +18945,20 @@ Base Services
 @cindex jackd
 @cindex nofile
 @cindex open file descriptors
-@deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
-
-Return a service that installs a configuration file for the
+@anchor{pam-limits-service-type}
+@defvar pam-limits-service-type
+Type of the service that installs a configuration file for the
 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
-@code{pam_limits} module}.  The procedure optionally takes a list of
-@code{pam-limits-entry} values, which can be used to specify
+@code{pam_limits} module}.  The value for this service type is
+a list of @code{pam-limits-entry} values, which can be used to specify
 @code{ulimit} limits and @code{nice} priority limits to user sessions.
+By default, the value is the empty list.
 
 The following limits definition sets two hard and soft limits for all
 login sessions of users in the @code{realtime} group:
 
 @lisp
-(pam-limits-service
+(service pam-limits-service-type
  (list
   (pam-limits-entry "@@realtime" 'both 'rtprio 99)
   (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
@@ -18973,7 +18973,7 @@ Base Services
 descriptors that can be used:
 
 @lisp
-(pam-limits-service
+(service pam-limits-service-type
  (list
   (pam-limits-entry "*" 'both 'nofile 100000)))
 @end lisp
@@ -18984,7 +18984,7 @@ Base Services
 else the users would be prevented from login in.  For more information
 about the Pluggable Authentication Module (PAM) limits, refer to the
 @samp{pam_limits} man page from the @code{linux-pam} package.
-@end deffn
+@end defvar
 
 @defvar greetd-service-type
 @uref{https://git.sr.ht/~kennylevinsen/greetd, @code{greetd}} is a minimal and
diff --git a/gnu/packages/benchmark.scm b/gnu/packages/benchmark.scm
index 33e2466da9..fd8513f41d 100644
--- a/gnu/packages/benchmark.scm
+++ b/gnu/packages/benchmark.scm
@@ -458,7 +458,7 @@ (define-public python-locust
 
 Note: Locust will complain if the available open file descriptors limit for
 the user is too low.  To raise such limit on a Guix System, refer to
-@samp{info guix --index-search=pam-limits-service}.")
+@samp{info guix --index-search=pam-limits-service-type}.")
     (license license:expat)))
 
 (define-public interbench
diff --git a/gnu/services/base.scm b/gnu/services/base.scm
index 1423ab6767..bda38abae3 100644
--- a/gnu/services/base.scm
+++ b/gnu/services/base.scm
@@ -40,7 +40,7 @@
 (define-module (gnu services base)
   #:use-module (guix store)
   #:use-module (guix deprecation)
-  #:autoload   (guix diagnostics) (warning &fix-hint)
+  #:autoload   (guix diagnostics) (warning report-error &fix-hint)
   #:autoload   (guix i18n) (G_)
   #:use-module (guix combinators)
   #:use-module (gnu services)
@@ -246,7 +246,7 @@ (define-module (gnu services base)
             kmscon-service-type
 
             pam-limits-service-type
-            pam-limits-service
+            pam-limits-service  ; deprecated
 
             greetd-service-type
             greetd-configuration
@@ -1584,17 +1584,13 @@ (define-deprecated (syslog-service #:optional (config (syslog-configuration)))
 
 
 (define pam-limits-service-type
-  (let ((security-limits
-         ;; Create /etc/security containing the provided "limits.conf" file.
-         (lambda (limits-file)
-           `(("security/limits.conf"
-              ,limits-file))))
-        (pam-extension
+  (let ((pam-extension
          (lambda (pam)
            (let ((pam-limits (pam-entry
                               (control "required")
                               (module "pam_limits.so")
-                              (arguments '("conf=/etc/security/limits.conf")))))
+                              (arguments
+                               '("conf=/etc/security/limits.conf")))))
              (if (member (pam-service-name pam)
                          '("login" "greetd" "su" "slim" "gdm-password" "sddm"
                            "sudo" "sshd"))
@@ -1602,7 +1598,26 @@ (define pam-limits-service-type
                   (inherit pam)
                   (session (cons pam-limits
                                  (pam-service-session pam))))
-                 pam)))))
+                 pam))))
+
+        ;; XXX: Using file-like objects is deprecated, use lists instead.
+        ;;      This is to be reduced into the list? case when the deprecated
+        ;;      code gets removed.
+        ;; Create /etc/security containing the provided "limits.conf" file.
+        (security-limits
+         (match-lambda
+           ((? file-like? obj)
+            (warning (G_ "Using file-like value for 'pam-limits-service-type'
+is deprecated~%"))
+            obj)
+           ((? list? lst)
+            `(("security/limits.conf"
+               ,(plain-file "limits.conf"
+                            (string-join (map pam-limits-entry->string lst)
+                                         "\n" 'suffix)))))
+           (_ (report-error
+               (G_ "invalid input for 'pam-limits-service-type'~%"))))))
+
     (service-type
      (name 'limits)
      (extensions
@@ -1612,9 +1627,11 @@ (define pam-limits-service-type
      (description
       "Install the specified resource usage limits by populating
 @file{/etc/security/limits.conf} and using the @code{pam_limits}
-authentication module."))))
+authentication module.")
+     (default-value '()))))
 
-(define* (pam-limits-service #:optional (limits '()))
+(define-deprecated (pam-limits-service #:optional (limits '()))
+  pam-limits-service-type
   "Return a service that makes selected programs respect the list of
 pam-limits-entry specified in LIMITS via pam_limits.so."
   (service pam-limits-service-type
-- 
2.39.1