guix-play/gnu/services/databases.scm
David Thompson 105369a46b gnu: Add postgresql-service.
* gnu/services/databases.scm: New file.
* gnu-system.am (GNU_SYSTEM_MODULES): Add it.
* doc/guix.texi ("Database Services"): New subsubsection.
2015-05-07 08:44:36 -04:00

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Scheme

;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2015 David Thompson <davet@gnu.org>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; GNU Guix is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
(define-module (gnu services databases)
#:use-module (gnu services)
#:use-module (gnu system shadow)
#:use-module (gnu packages admin)
#:use-module (gnu packages databases)
#:use-module (guix records)
#:use-module (guix monads)
#:use-module (guix store)
#:use-module (guix gexp)
#:export (postgresql-service))
;;; Commentary:
;;;
;;; Database services.
;;;
;;; Code:
(define %default-postgres-hba
(text-file "pg_hba.conf"
"
local all all trust
host all all 127.0.0.1/32 trust
host all all ::1/128 trust"))
(define %default-postgres-ident
(text-file "pg_ident.conf"
"# MAPNAME SYSTEM-USERNAME PG-USERNAME"))
(define %default-postgres-config
(mlet %store-monad ((hba %default-postgres-hba)
(ident %default-postgres-ident))
(text-file* "postgresql.conf"
;; The daemon will not start without these.
"hba_file = '" hba "'\n"
"ident_file = '" ident "'\n")))
(define* (postgresql-service #:key (postgresql postgresql)
(config-file %default-postgres-config)
(data-directory "/var/lib/postgresql/data"))
"Return a service that runs @var{postgresql}, the PostgreSQL database server.
The PostgreSQL daemon loads its runtime configuration from @var{config-file}
and stores the database cluster in @var{data-directory}."
;; Wrapper script that switches to the 'postgres' user before launching
;; daemon.
(define start-script
(mlet %store-monad ((config-file config-file))
(gexp->script "start-postgres"
#~(let ((user (getpwnam "postgres"))
(postgres (string-append #$postgresql
"/bin/postgres")))
(setgid (passwd:gid user))
(setuid (passwd:uid user))
(system* postgres
(string-append "--config-file=" #$config-file)
"-D" #$data-directory)))))
(define activate
#~(begin
(use-modules (guix build utils)
(ice-9 match))
(let ((user (getpwnam "postgres"))
(initdb (string-append #$postgresql "/bin/initdb")))
;; 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 (system* initdb "-D" #$data-directory)))
(lambda ()
(primitive-exit 1))))
(pid (waitpid pid))))))
(mlet %store-monad ((start-script start-script))
(return
(service
(provision '(postgres))
(documentation "Run the PostgreSQL daemon.")
(requirement '(user-processes loopback))
(start #~(make-forkexec-constructor #$start-script))
(stop #~(make-kill-destructor))
(activate activate)
(user-groups (list (user-group
(name "postgres")
(system? #t))))
(user-accounts (list (user-account
(name "postgres")
(group "postgres")
(system? #t)
(comment "PostgreSQL server user")
(home-directory "/var/empty")
(shell
#~(string-append #$shadow "/sbin/nologin")))))))))