[bug#42899] [PATCH v3 2/9] services: dovecot: Use modules via symlink to system profile.

[Alexey Abramov <levenson@mmer.org>]

* gnu/services/mail.scm (%dovecot-activation): Link the location with multiple
plugins (dovecot-pigeonhole, etc), to a place where dovecot can find them.
* gnu/services/mail.scm (dovecot-configuration): Use the symlink.
---
 doc/guix.texi         |  9 +++++++--
 gnu/services/mail.scm | 13 ++++++++++---
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/doc/guix.texi b/doc/guix.texi
index 0b79a49814..dfa83c409c 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -18360,8 +18360,13 @@ Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
 @end deftypevr
 
 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
-Directory where to look up mail plugins.
-Defaults to @samp{"/usr/lib/dovecot"}.
+Directory where to look up mail plugins.  In Guix, dovecot plugins have
+all its modules under /gnu/store/xxx-plugin/(lib|libexec)/dovecot. To be
+able to load all those modules by doveconf or services like sieve,
+@samp{mail-plugin-dir} is a symlink "/run/current-system/profile/lib/dovecot",
+which creates during the activation step.
+
+Defaults to @samp{"/etc/dovecot/modules"}.
 @end deftypevr
 
 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
diff --git a/gnu/services/mail.scm b/gnu/services/mail.scm
index cfcaf4601b..2832303d88 100644
--- a/gnu/services/mail.scm
+++ b/gnu/services/mail.scm
@@ -1044,8 +1044,12 @@ directories are prefixed with the chroot directory, append \"/.\" to
 This is used by imap (for shared users) and lda.")
 
   (mail-plugin-dir
-   (file-name "/usr/lib/dovecot")
-   "Directory where to look up mail plugins.")
+   (file-name "/etc/dovecot/modules")
+   "Directory where to look up mail plugins.  In Guix, dovecot plugins have
+all its modules under /gnu/store/xxx-plugin/(lib|libexec)/dovecot. To be able
+to load all those modules by doveconf or services like imap,
+@samp{mail-plugin-dir} is a symlink `/run/current-system/profile/lib/dovecot`,
+which creates during the activation step.")
 
   (mail-plugins
    (space-separated-string-list '())
@@ -1519,13 +1523,16 @@ greyed out, instead of only later giving \"not selectable\" popup error.
              (else
               (format (current-error-port)
                       "Failed to create public key at ~a.\n" public-key)))))
-        (let ((user (getpwnam "dovecot")))
+        (let ((user (getpwnam "dovecot"))
+              (moduledir "/etc/dovecot/modules"))
           (mkdir-p/perms "/var/run/dovecot" user #o755)
           (mkdir-p/perms "/var/lib/dovecot" user #o755)
           (mkdir-p/perms "/etc/dovecot" user #o755)
           (copy-file #$(plain-file "dovecot.conf" config-str)
                      "/etc/dovecot/dovecot.conf")
           (mkdir-p/perms "/etc/dovecot/private" user #o700)
+          (unless (file-exists? moduledir)
+            (symlink "/run/current-system/profile/lib/dovecot" moduledir))
           (create-self-signed-certificate-if-absent
            #:private-key "/etc/dovecot/private/default.pem"
            #:public-key "/etc/dovecot/default.pem"
-- 
2.28.0