[shepherd] 02/03: service: Export 'default-environment-variables'.

[Ludovic Courtès]

civodul pushed a commit to branch master
in repository shepherd.

commit 501d62c4d235045e79e5aef684b5a9250c1cf8c4
Author: Ludovic Courtès <address@hidden>
AuthorDate: Mon Feb 3 22:27:26 2020 +0100

    service: Export 'default-environment-variables'.
    
    * modules/shepherd/service.scm (default-environment-variables): Turn
    into a parameter and export.
    * doc/shepherd.texi (Service De- and Constructors): Document it.
---
 doc/shepherd.texi            | 13 ++++++++++++-
 modules/shepherd/service.scm | 12 +++++++-----
 2 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/doc/shepherd.texi b/doc/shepherd.texi
index e652fc4..da5718b 100644
--- a/doc/shepherd.texi
+++ b/doc/shepherd.texi
@@ -6,7 +6,7 @@
 
 @include version.texi
 @set OLD-YEARS 2002, 2003
-@set NEW-YEARS 2013, 2016, 2018
+@set NEW-YEARS 2013, 2016, 2018, 2019, 2020
 
 @copying
 Copyright @copyright{} @value{OLD-YEARS} Wolfgang J@"ahrling@*
@@ -947,6 +947,17 @@ unless the @var{group} keyword argument is present and not 
false.
 a separate process whose PID it returns.
 @end deffn
 
+@defvr {Scheme Variable} default-environment-variables
+This parameter (@pxref{Parameters,,, guile, GNU Guile Reference Manual})
+specifies the default list of environment variables to be defined when
+the procedures above create a new process.
+
+It must be a list of strings where each string has the format
+@code{@var{name}=@var{value}}.  It defaults to what @code{environ}
+returns when the program starts (@pxref{Runtime Environment,
+@code{environ},, guile, GNU Guile Reference Manual}).
+@end defvr
+
 @c @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
 
 @node Service Examples
diff --git a/modules/shepherd/service.scm b/modules/shepherd/service.scm
index 321ae58..e0772e8 100644
--- a/modules/shepherd/service.scm
+++ b/modules/shepherd/service.scm
@@ -1,5 +1,5 @@
 ;; service.scm -- Representation of services.
-;; Copyright (C) 2013, 2014, 2015, 2016, 2017, 2018, 2019 Ludovic Courtès 
<address@hidden>
+;; Copyright (C) 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020 Ludovic 
Courtès <address@hidden>
 ;; Copyright (C) 2002, 2003 Wolfgang Järling <address@hidden>
 ;; Copyright (C) 2014 Alex Sassmannshausen <address@hidden>
 ;; Copyright (C) 2016 Alex Kost <address@hidden>
@@ -70,6 +70,8 @@
             provided-by
             required-by
             handle-unknown
+
+            default-environment-variables
             make-forkexec-constructor
             make-kill-destructor
             exec-command
@@ -712,10 +714,10 @@ results."
                                passwd:dir)
                         (getcwd)))))
 
-(define (default-environment-variables)
-  "Return the list of environment variable name/value pairs that should be
-set when starting a service."
-  (environ))
+(define default-environment-variables
+  ;; The default list of environment variable name/value pairs that should be
+  ;; set when starting a service.
+  (make-parameter (environ)))
 
 (define* (read-pid-file file #:key (max-delay 5)
                         (validate-pid? #f))