446 lines
16 KiB
Scheme
446 lines
16 KiB
Scheme
;;; GNU Guix --- Functional package management for GNU
|
||
;;; Copyright © 2015 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 services)
|
||
#:use-module (guix gexp)
|
||
#:use-module (guix monads)
|
||
#:use-module (guix store)
|
||
#:use-module (guix records)
|
||
#:use-module (guix sets)
|
||
#:use-module (guix ui)
|
||
#:use-module (gnu packages base)
|
||
#:use-module (gnu packages bash)
|
||
#:use-module (srfi srfi-1)
|
||
#:use-module (srfi srfi-9)
|
||
#:use-module (srfi srfi-9 gnu)
|
||
#:use-module (srfi srfi-26)
|
||
#:use-module (srfi srfi-34)
|
||
#:use-module (srfi srfi-35)
|
||
#:use-module (ice-9 vlist)
|
||
#:use-module (ice-9 match)
|
||
#:export (service-extension
|
||
service-extension?
|
||
|
||
service-type
|
||
service-type?
|
||
|
||
service
|
||
service?
|
||
service-kind
|
||
service-parameters
|
||
|
||
fold-services
|
||
|
||
service-error?
|
||
missing-target-service-error?
|
||
missing-target-service-error-service
|
||
missing-target-service-error-target-type
|
||
ambiguous-target-service-error?
|
||
ambiguous-target-service-error-service
|
||
ambiguous-target-service-error-target-type
|
||
|
||
boot-service-type
|
||
activation-service-type
|
||
activation-service->script
|
||
etc-service-type
|
||
etc-directory
|
||
setuid-program-service-type
|
||
firmware-service-type
|
||
|
||
%boot-service
|
||
%activation-service
|
||
etc-service
|
||
|
||
file-union)) ;XXX: for lack of a better place
|
||
|
||
;;; Comment:
|
||
;;;
|
||
;;; This module defines a broad notion of "service types" and "services."
|
||
;;;
|
||
;;; A service type describe how its instances extend instances of other
|
||
;;; service types. For instance, some services extend the instance of
|
||
;;; ACCOUNT-SERVICE-TYPE by providing it with accounts and groups to create;
|
||
;;; others extend DMD-ROOT-SERVICE-TYPE by passing it instances of
|
||
;;; <dmd-service>.
|
||
;;;
|
||
;;; When applicable, the service type defines how it can itself be extended,
|
||
;;; by providing one procedure to compose extensions, and one procedure to
|
||
;;; extend itself.
|
||
;;;
|
||
;;; A notable service type is BOOT-SERVICE-TYPE, which has a single instance,
|
||
;;; %BOOT-SERVICE. %BOOT-SERVICE constitutes the root of the service DAG. It
|
||
;;; produces the boot script that the initrd loads.
|
||
;;;
|
||
;;; The 'fold-services' procedure can be passed a list of procedures, which it
|
||
;;; "folds" by propagating extensions down the graph; it returns the root
|
||
;;; service after the applying all its extensions.
|
||
;;;
|
||
;;; Code:
|
||
|
||
(define-record-type <service-extension>
|
||
(service-extension target compute)
|
||
service-extension?
|
||
(target service-extension-target) ;<service-type>
|
||
(compute service-extension-compute)) ;params -> params
|
||
|
||
(define-record-type* <service-type> service-type make-service-type
|
||
service-type?
|
||
(name service-type-name) ;symbol (for debugging)
|
||
|
||
;; Things extended by services of this type.
|
||
(extensions service-type-extensions) ;list of <service-extensions>
|
||
|
||
;; Given a list of extensions, "compose" them.
|
||
(compose service-type-compose ;list of Any -> Any
|
||
(default #f))
|
||
|
||
;; Extend the services' own parameters with the extension composition.
|
||
(extend service-type-extend ;list of Any -> parameters
|
||
(default #f)))
|
||
|
||
(define (write-service-type type port)
|
||
(format port "#<service-type ~a ~a>"
|
||
(service-type-name type)
|
||
(number->string (object-address type) 16)))
|
||
|
||
(set-record-type-printer! <service-type> write-service-type)
|
||
|
||
;; Services of a given type.
|
||
(define-record-type <service>
|
||
(service type parameters)
|
||
service?
|
||
(type service-kind)
|
||
(parameters service-parameters))
|
||
|
||
|
||
|
||
|
||
;;;
|
||
;;; Core services.
|
||
;;;
|
||
|
||
(define (compute-boot-script mexps)
|
||
(mlet %store-monad ((gexps (sequence %store-monad mexps)))
|
||
(gexp->file "boot"
|
||
#~(begin
|
||
(use-modules (guix build utils))
|
||
|
||
;; Clean out /tmp and /var/run.
|
||
;;
|
||
;; XXX This needs to happen before service activations, so
|
||
;; it has to be here, but this also implicitly assumes
|
||
;; that /tmp and /var/run are on the root partition.
|
||
(false-if-exception (delete-file-recursively "/tmp"))
|
||
(false-if-exception (delete-file-recursively "/var/run"))
|
||
(false-if-exception (mkdir "/tmp"))
|
||
(false-if-exception (chmod "/tmp" #o1777))
|
||
(false-if-exception (mkdir "/var/run"))
|
||
(false-if-exception (chmod "/var/run" #o755))
|
||
|
||
;; Activate the system and spawn dmd.
|
||
#$@gexps))))
|
||
|
||
(define (second-argument a b) b)
|
||
|
||
(define boot-service-type
|
||
;; The service of this type is extended by being passed gexps as monadic
|
||
;; values. It aggregates them in a single script, as a monadic value, which
|
||
;; becomes its 'parameters'. It is the only service that extends nothing.
|
||
(service-type (name 'boot)
|
||
(extensions '())
|
||
(compose compute-boot-script)
|
||
(extend second-argument)))
|
||
|
||
(define %boot-service
|
||
;; This is the ultimate service, the root of the service DAG.
|
||
(service boot-service-type #t))
|
||
|
||
(define* (file-union name files) ;FIXME: Factorize.
|
||
"Return a <computed-file> that builds a directory containing all of FILES.
|
||
Each item in FILES must be a list where the first element is the file name to
|
||
use in the new directory, and the second element is a gexp denoting the target
|
||
file."
|
||
(computed-file name
|
||
#~(begin
|
||
(mkdir #$output)
|
||
(chdir #$output)
|
||
#$@(map (match-lambda
|
||
((target source)
|
||
#~(symlink #$source #$target)))
|
||
files))))
|
||
|
||
(define (directory-union name things)
|
||
"Return a directory that is the union of THINGS."
|
||
(match things
|
||
((one)
|
||
;; Only one thing; return it.
|
||
one)
|
||
(_
|
||
(computed-file name
|
||
#~(begin
|
||
(use-modules (guix build union))
|
||
(union-build #$output '#$things))
|
||
#:modules '((guix build union))))))
|
||
|
||
(define (modprobe-wrapper)
|
||
"Return a wrapper for the 'modprobe' command that knows where modules live.
|
||
|
||
This wrapper is typically invoked by the Linux kernel ('call_modprobe', in
|
||
kernel/kmod.c), a situation where the 'LINUX_MODULE_DIRECTORY' environment
|
||
variable is not set---hence the need for this wrapper."
|
||
(let ((modprobe "/run/current-system/profile/bin/modprobe"))
|
||
(gexp->script "modprobe"
|
||
#~(begin
|
||
(setenv "LINUX_MODULE_DIRECTORY"
|
||
"/run/booted-system/kernel/lib/modules")
|
||
(apply execl #$modprobe
|
||
(cons #$modprobe (cdr (command-line))))))))
|
||
|
||
(define* (activation-service->script service)
|
||
"Return as a monadic value the activation script for SERVICE, a service of
|
||
ACTIVATION-SCRIPT-TYPE."
|
||
(activation-script (service-parameters service)))
|
||
|
||
(define (activation-script gexps)
|
||
"Return the system's activation script, which evaluates GEXPS."
|
||
(define %modules
|
||
'((gnu build activation)
|
||
(gnu build linux-boot)
|
||
(gnu build linux-modules)
|
||
(gnu build file-systems)
|
||
(guix build utils)
|
||
(guix build syscalls)
|
||
(guix elf)))
|
||
|
||
(define (service-activations)
|
||
;; Return the activation scripts for SERVICES.
|
||
(mapm %store-monad
|
||
(cut gexp->file "activate-service" <>)
|
||
gexps))
|
||
|
||
(mlet* %store-monad ((actions (service-activations))
|
||
(modules (imported-modules %modules))
|
||
(compiled (compiled-modules %modules))
|
||
(modprobe (modprobe-wrapper)))
|
||
(gexp->file "activate"
|
||
#~(begin
|
||
(eval-when (expand load eval)
|
||
;; Make sure 'use-modules' below succeeds.
|
||
(set! %load-path (cons #$modules %load-path))
|
||
(set! %load-compiled-path
|
||
(cons #$compiled %load-compiled-path)))
|
||
|
||
(use-modules (gnu build activation))
|
||
|
||
;; Make sure /bin/sh is valid and current.
|
||
(activate-/bin/sh
|
||
(string-append #$(canonical-package bash) "/bin/sh"))
|
||
|
||
;; Tell the kernel to use our 'modprobe' command.
|
||
(activate-modprobe #$modprobe)
|
||
|
||
;; Let users debug their own processes!
|
||
(activate-ptrace-attach)
|
||
|
||
;; Run the services' activation snippets.
|
||
;; TODO: Use 'load-compiled'.
|
||
(for-each primitive-load '#$actions)
|
||
|
||
;; Set up /run/current-system.
|
||
(activate-current-system)))))
|
||
|
||
(define (gexps->activation-gexp gexps)
|
||
"Return a gexp that runs the activation script containing GEXPS."
|
||
(mlet %store-monad ((script (activation-script gexps)))
|
||
(return #~(primitive-load #$script))))
|
||
|
||
(define activation-service-type
|
||
(service-type (name 'activate)
|
||
(extensions
|
||
(list (service-extension boot-service-type
|
||
gexps->activation-gexp)))
|
||
(compose append)
|
||
(extend second-argument)))
|
||
|
||
(define %activation-service
|
||
;; The activation service produces the activation script from the gexps it
|
||
;; receives.
|
||
(service activation-service-type #t))
|
||
|
||
(define (etc-directory service)
|
||
"Return the directory for SERVICE, a service of type ETC-SERVICE-TYPE."
|
||
(files->etc-directory (service-parameters service)))
|
||
|
||
(define (files->etc-directory files)
|
||
(file-union "etc" files))
|
||
|
||
(define etc-service-type
|
||
(service-type (name 'etc)
|
||
(extensions
|
||
(list
|
||
(service-extension activation-service-type
|
||
(lambda (files)
|
||
(let ((etc
|
||
(files->etc-directory files)))
|
||
#~(activate-etc #$etc))))))
|
||
(compose concatenate)
|
||
(extend append)))
|
||
|
||
(define (etc-service files)
|
||
"Return a new service of ETC-SERVICE-TYPE that populates /etc with FILES.
|
||
FILES must be a list of name/file-like object pairs."
|
||
(service etc-service-type files))
|
||
|
||
(define setuid-program-service-type
|
||
(service-type (name 'setuid-program)
|
||
(extensions
|
||
(list (service-extension activation-service-type
|
||
(lambda (programs)
|
||
#~(activate-setuid-programs
|
||
(list #$@programs))))))
|
||
(compose concatenate)
|
||
(extend append)))
|
||
|
||
(define (firmware->activation-gexp firmware)
|
||
"Return a gexp to make the packages listed in FIRMWARE loadable by the
|
||
kernel."
|
||
(let ((directory (directory-union "firmware" firmware)))
|
||
;; Tell the kernel where firmware is.
|
||
#~(activate-firmware (string-append #$directory "/lib/firmware"))))
|
||
|
||
(define firmware-service-type
|
||
;; The service that collects firmware.
|
||
(service-type (name 'firmware)
|
||
(extensions
|
||
(list (service-extension activation-service-type
|
||
firmware->activation-gexp)))
|
||
(compose concatenate)
|
||
(extend append)))
|
||
|
||
|
||
;;;
|
||
;;; Service folding.
|
||
;;;
|
||
|
||
(define-condition-type &service-error &error
|
||
service-error?)
|
||
|
||
(define-condition-type &missing-target-service-error &service-error
|
||
missing-target-service-error?
|
||
(service missing-target-service-error-service)
|
||
(target-type missing-target-service-error-target-type))
|
||
|
||
(define-condition-type &ambiguous-target-service-error &service-error
|
||
ambiguous-target-service-error?
|
||
(service ambiguous-target-service-error-service)
|
||
(target-type ambiguous-target-service-error-target-type))
|
||
|
||
(define (service-back-edges services)
|
||
"Return a procedure that, when passed a <service>, returns the list of
|
||
<service> objects that depend on it."
|
||
(define (add-edges service edges)
|
||
(define (add-edge extension edges)
|
||
(let ((target-type (service-extension-target extension)))
|
||
(match (filter (lambda (service)
|
||
(eq? (service-kind service) target-type))
|
||
services)
|
||
((target)
|
||
(vhash-consq target service edges))
|
||
(()
|
||
(raise
|
||
(condition (&missing-target-service-error
|
||
(service service)
|
||
(target-type target-type))
|
||
(&message
|
||
(message
|
||
(format #f (_ "no target of type '~a' for service ~s")
|
||
(service-type-name target-type)
|
||
service))))))
|
||
(x
|
||
(raise
|
||
(condition (&ambiguous-target-service-error
|
||
(service service)
|
||
(target-type target-type))
|
||
(&message
|
||
(message
|
||
(format #f
|
||
(_ "more than one target service of type '~a'")
|
||
(service-type-name target-type))))))))))
|
||
|
||
(fold add-edge edges (service-type-extensions (service-kind service))))
|
||
|
||
(let ((edges (fold add-edges vlist-null services)))
|
||
(lambda (node)
|
||
(reverse (vhash-foldq* cons '() node edges)))))
|
||
|
||
(define* (fold-services services #:key (target-type boot-service-type))
|
||
"Fold SERVICES by propagating their extensions down to the root of type
|
||
TARGET-TYPE; return the root service adjusted accordingly."
|
||
(define dependents
|
||
(service-back-edges services))
|
||
|
||
(define (matching-extension target)
|
||
(let ((target (service-kind target)))
|
||
(match-lambda
|
||
(($ <service-extension> type)
|
||
(eq? type target)))))
|
||
|
||
(define (apply-extension target)
|
||
(lambda (service)
|
||
(match (find (matching-extension target)
|
||
(service-type-extensions (service-kind service)))
|
||
(($ <service-extension> _ compute)
|
||
(compute (service-parameters service))))))
|
||
|
||
(match (filter (lambda (service)
|
||
(eq? (service-kind service) target-type))
|
||
services)
|
||
((sink)
|
||
(let loop ((sink sink))
|
||
(let* ((dependents (map loop (dependents sink)))
|
||
(extensions (map (apply-extension sink) dependents))
|
||
(extend (service-type-extend (service-kind sink)))
|
||
(compose (service-type-compose (service-kind sink)))
|
||
(params (service-parameters sink)))
|
||
;; We distinguish COMPOSE and EXTEND because PARAMS typically has a
|
||
;; different type than the elements of EXTENSIONS.
|
||
(if extend
|
||
(service (service-kind sink)
|
||
(extend params (compose extensions)))
|
||
sink))))
|
||
(()
|
||
(raise
|
||
(condition (&missing-target-service-error
|
||
(service #f)
|
||
(target-type target-type))
|
||
(&message
|
||
(message (format #f (_ "service of type '~a' not found")
|
||
(service-type-name target-type)))))))
|
||
(x
|
||
(raise
|
||
(condition (&ambiguous-target-service-error
|
||
(service #f)
|
||
(target-type target-type))
|
||
(&message
|
||
(message
|
||
(format #f
|
||
(_ "more than one target service of type '~a'")
|
||
(service-type-name target-type)))))))))
|
||
|
||
;;; services.scm ends here.
|