Subject: [PATCH] gnu: services: postgresql: Don't initdb when directory exists

From: Robert Vollmert <[email-masked]>
Date: Sun, 30 Jun 2019 22:56:42 +0200

* gnu/services/databases.scm (postgresql-activation): Check if
directory exists.
---
 gnu/services/databases.scm | 63 +++++++++++++++++++-------------------
 1 file changed, 32 insertions(+), 31 deletions(-)

diff --git a/gnu/services/databases.scm b/gnu/services/databases.scm
index ec31489d48..6b04ae0a0f 100644
--- a/gnu/services/databases.scm
+++ b/gnu/services/databases.scm
@@ -196,37 +196,38 @@ host	all	all	::1/128 	md5"))
          (use-modules (guix build utils)
                       (ice-9 match))
 
-         (let ((user (getpwnam "postgres"))
-               (initdb (string-append #$(final-postgresql postgresql extension-packages)
-                                      "/bin/initdb"))
-               (initdb-args
-                (append
-                 (if #$locale
-                     (list (string-append "--locale=" #$locale))
-                     '()))))
-           ;; Create db state directory.
-           (mkdir-p #$data-directory)
-           (chown #$data-directory (passwd:uid user) (passwd:gid user))
-
-           ;; Drop privileges and init state directory in a new
-           ;; process.  Wait for it to finish before proceeding.
-           (match (primitive-fork)
-             (0
-              ;; Exit with a non-zero status code if an exception is thrown.
-              (dynamic-wind
-                (const #t)
-                (lambda ()
-                  (setgid (passwd:gid user))
-                  (setuid (passwd:uid user))
-                  (primitive-exit
-                   (apply system*
-                          initdb
-                          "-D"
-                          #$data-directory
-                          initdb-args)))
-                (lambda ()
-                  (primitive-exit 1))))
-             (pid (waitpid pid))))))))
+         (when (not (file-exists? #$data-directory))
+           (let ((user (getpwnam "postgres"))
+                 (initdb (string-append #$(final-postgresql postgresql extension-packages)
+                                        "/bin/initdb"))
+                 (initdb-args
+                  (append
+                   (if #$locale
+                       (list (string-append "--locale=" #$locale))
+                       '()))))
+             ;; Create db state directory.
+             (mkdir-p #$data-directory)
+             (chown #$data-directory (passwd:uid user) (passwd:gid user))
+
+             ;; Drop privileges and init state directory in a new
+             ;; process.  Wait for it to finish before proceeding.
+             (match (primitive-fork)
+               (0
+                ;; Exit with a non-zero status code if an exception is thrown.
+                (dynamic-wind
+                  (const #t)
+                  (lambda ()
+                    (setgid (passwd:gid user))
+                    (setuid (passwd:uid user))
+                    (primitive-exit
+                     (apply system*
+                            initdb
+                            "-D"
+                            #$data-directory
+                            initdb-args)))
+                  (lambda ()
+                    (primitive-exit 1))))
+               (pid (waitpid pid)))))))))
 
 (define postgresql-shepherd-service
   (match-lambda
-- 
2.20.1 (Apple Git-117)