services: postgresql: Log to stderr instead of syslog by default.

This corresponds to postgresql's own default; it means we can let go of the
syslogd dependency by default and arguably makes it easier to find some
postgresql related errors.

* doc/guix.texi (Database Services) <postgresl-config-file>: Adjust example
to showcase something different than the new default.  Change documented
default to stderr.
* gnu/services/databases.scm (<postgresql-config-file>)
[log-destination]: Change default value to stderr.
(postgresql-shepherd-service) <requirement>: Conditionally add
syslogd dependency only if found in log-destination value.
(postgresql-role-shepherd-service) <#:log-file>: Uncomment.

1 files changed, 2 insertions, 2 deletions

diff --git a/doc/guix.texi b/doc/guix.texi
index 7c37c2aba16..9c591faaccc 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -28929,7 +28929,7 @@ like to use for example.
          (postgresql-configuration
           (config-file
            (postgresql-config-file
-            (log-destination "stderr")
+            (log-destination "csvlog,stderr")
             (hba-file
              (plain-file "pg_hba.conf"
                          "
@@ -28946,7 +28946,7 @@ host	all	all	::1/128 	md5"))
 @end lisp
 
 @table @asis
-@item @code{log-destination} (default: @code{"syslog"})
+@item @code{log-destination} (default: @code{"stderr"})
 The logging method to use for PostgreSQL@.  Valid values are
 @code{"stderr"}, @code{"csvlog"}, @code{"jsonlog"}, @code{"syslog"} and
 @code{"eventlog"}.  Multiple values are accepted, separated by commas.