guix/gnu/system/install.scm
Ludovic Courtès 61ff0a3a18 install: Use a low-memory nscd caching policy.
* gnu/system/install.scm (%nscd-minimal-caches): New variable.
  (installation-services): Use as 'nscd-service' argument.
2014-12-14 17:26:03 +01:00

282 lines
10 KiB
Scheme

;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2014 Ludovic Courtès <ludo@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 system install)
#:use-module (gnu)
#:use-module (guix gexp)
#:use-module (guix monads)
#:use-module ((guix store) #:select (%store-prefix))
#:use-module (gnu packages admin)
#:use-module (gnu packages linux)
#:use-module (gnu packages cryptsetup)
#:use-module (gnu packages package-management)
#:use-module (gnu packages disk)
#:use-module (gnu packages grub)
#:use-module (gnu packages texinfo)
#:export (installation-os))
;;; Commentary:
;;;
;;; This module provides an 'operating-system' definition for use on images
;;; for USB sticks etc., for the installation of the GNU system.
;;;
;;; Code:
(define (log-to-info)
"Return a script that spawns the Info reader on the right section of the
manual."
(gexp->script "log-to-info"
#~(execl (string-append #$texinfo-4 "/bin/info") "info"
"-d" "/run/current-system/profile/share/info"
"-f" (string-append #$guix "/share/info/guix.info")
"-n" "System Installation")))
(define %backing-directory
;; Sub-directory used as the backing store for copy-on-write.
"/tmp/guix-inst")
(define (make-cow-store target)
"Return a gexp that makes the store copy-on-write, using TARGET as the
backing store. This is useful when TARGET is on a hard disk, whereas the
current store is on a RAM disk."
(define (unionfs read-only read-write mount-point)
;; Make MOUNT-POINT the union of READ-ONLY and READ-WRITE.
;; Note: in the command below, READ-WRITE appears before READ-ONLY so that
;; it is considered a "higher-level branch", as per unionfs-fuse(8),
;; thereby allowing files existing on READ-ONLY to be copied over to
;; READ-WRITE.
#~(fork+exec-command
(list (string-append #$unionfs-fuse "/bin/unionfs")
"-o"
"cow,allow_other,use_ino,max_files=65536,nonempty"
(string-append #$read-write "=RW:" #$read-only "=RO")
#$mount-point)))
(define (set-store-permissions directory)
;; Set the right perms on DIRECTORY to use it as the store.
#~(begin
(chown #$directory 0 30000) ;use the fixed 'guixbuild' GID
(chmod #$directory #o1775)))
#~(begin
(unless (file-exists? "/.ro-store")
(mkdir "/.ro-store")
(mount #$(%store-prefix) "/.ro-store" "none"
(logior MS_BIND MS_RDONLY)))
(let ((rw-dir (string-append target #$%backing-directory)))
(mkdir-p rw-dir)
(mkdir-p "/.rw-store")
#$(set-store-permissions #~rw-dir)
#$(set-store-permissions "/.rw-store")
;; Mount the union, then atomically make it the store.
(and #$(unionfs "/.ro-store" #~rw-dir "/.rw-store")
(begin
(sleep 1) ;XXX: wait for unionfs to be ready
(mount "/.rw-store" #$(%store-prefix) "" MS_MOVE)
(rmdir "/.rw-store"))))))
(define (cow-store-service)
"Return a service that makes the store copy-on-write, such that writes go to
the user's target storage device rather than on the RAM disk."
;; See <http://bugs.gnu.org/18061> for the initial report.
(with-monad %store-monad
(return (service
(requirement '(root-file-system user-processes))
(provision '(cow-store))
(documentation
"Make the store copy-on-write, with writes going to \
the given target.")
;; This is meant to be explicitly started by the user.
(auto-start? #f)
(start #~(case-lambda
((target)
#$(make-cow-store #~target)
target)
(else
;; Do nothing, and mark the service as stopped.
#f)))
(stop #~(lambda (target)
;; Delete the temporary directory, but leave everything
;; mounted as there may still be processes using it
;; since 'user-processes' doesn't depend on us. The
;; 'user-unmount' service will unmount TARGET
;; eventually.
(delete-file-recursively
(string-append target #$%backing-directory))))))))
(define (configuration-template-service)
"Return a dummy service whose purpose is to install an operating system
configuration template file in the installation system."
(define local-template
"/etc/configuration-template.scm")
(define template
(search-path %load-path "gnu/system/os-config.tmpl"))
(mlet %store-monad ((template (interned-file template)))
(return (service
(requirement '(root-file-system))
(provision '(os-config-template))
(documentation
"This dummy service installs an OS configuration template.")
(start #~(const #t))
(stop #~(const #f))
(activate
#~(unless (file-exists? #$local-template)
(copy-file #$template #$local-template)))))))
(define %nscd-minimal-caches
;; Minimal in-memory caching policy for nscd.
(list (nscd-cache (database 'hosts)
(positive-time-to-live (* 3600 12))
(negative-time-to-live 20)
(persistent? #f)
(max-database-size (* 5 (expt 2 20)))))) ;5 MiB
(define (installation-services)
"Return the list services for the installation image."
(let ((motd (text-file "motd" "
Welcome to the installation of the GNU operating system!
There is NO WARRANTY, to the extent permitted by law. In particular, you may
LOSE ALL YOUR DATA as a side effect of the installation process. Furthermore,
it is alpha software, so it may BREAK IN UNEXPECTED WAYS.
You have been warned. Thanks for being so brave.
")))
(define (normal-tty tty)
(mingetty-service tty
#:motd motd
#:auto-login "root"
#:login-pause? #t))
(list (mingetty-service "tty1"
#:motd motd
#:auto-login "root")
;; Documentation. The manual is in UTF-8, but
;; 'console-font-service' sets up Unicode support and loads a font
;; with all the useful glyphs like em dash and quotation marks.
(mingetty-service "tty2"
#:motd motd
#:auto-login "guest"
#:login-program (log-to-info))
;; Documentation add-on.
(configuration-template-service)
;; A bunch of 'root' ttys.
(normal-tty "tty3")
(normal-tty "tty4")
(normal-tty "tty5")
(normal-tty "tty6")
;; The usual services.
(syslog-service)
;; The build daemon. Register the hydra.gnu.org key as trusted.
;; This allows the installation process to use substitutes by
;; default.
(guix-service #:authorize-hydra-key? #t)
;; Start udev so that useful device nodes are available.
(udev-service)
;; Add the 'cow-store' service, which users have to start manually
;; since it takes the installation directory as an argument.
(cow-store-service)
;; Install Unicode support and a suitable font.
(console-font-service "tty1")
(console-font-service "tty2")
(console-font-service "tty3")
(console-font-service "tty4")
(console-font-service "tty5")
(console-font-service "tty6")
;; Since this is running on a USB stick with a unionfs as the root
;; file system, use an appropriate cache configuration.
(nscd-service (nscd-configuration
(caches %nscd-minimal-caches))))))
(define %issue
;; Greeting.
"
This is an installation image of the GNU system. Welcome.
Use Alt-F2 for documentation.
")
(define installation-os
;; The operating system used on installation images for USB sticks etc.
(operating-system
(host-name "gnu")
(timezone "Europe/Paris")
(locale "en_US.utf8")
(bootloader (grub-configuration
(device "/dev/sda")))
(file-systems
;; Note: the disk image build code overrides this root file system with
;; the appropriate one.
(cons (file-system
(mount-point "/")
(device "gnu-disk-image")
(type "ext4"))
%base-file-systems))
(users (list (user-account
(name "guest")
(group "users")
(supplementary-groups '("wheel")) ; allow use of sudo
(password "")
(comment "Guest of GNU")
(home-directory "/home/guest"))))
(issue %issue)
(services (installation-services))
;; We don't need setuid programs so pass the empty list so we don't pull
;; additional programs here.
(setuid-programs '())
(pam-services
;; Explicitly allow for empty passwords.
(base-pam-services #:allow-empty-passwords? #t))
(packages (cons* texinfo-4 ;for the standalone Info reader
parted ddrescue
grub ;mostly so xrefs to its manual work
cryptsetup
wireless-tools wpa-supplicant
;; XXX: We used to have GNU fdisk here, but as of version
;; 2.0.0a, that pulls Guile 1.8, which takes unreasonable
;; space; furthermore util-linux's fdisk is already
;; available here, so we keep that.
%base-packages))))
;; Return it here so 'guix system' can consume it directly.
installation-os
;;; install.scm ends here