diff options
Diffstat (limited to 'gnu/services.scm')
| -rw-r--r-- | gnu/services.scm | 455 |
1 files changed, 417 insertions, 38 deletions
diff --git a/gnu/services.scm b/gnu/services.scm index 43e51b998c..fdfa569b23 100644 --- a/gnu/services.scm +++ b/gnu/services.scm @@ -1,5 +1,5 @@ ;;; GNU Guix --- Functional package management for GNU -;;; Copyright © 2013, 2014 Ludovic Courtès <ludo@gnu.org> +;;; Copyright © 2015 Ludovic Courtès <ludo@gnu.org> ;;; ;;; This file is part of GNU Guix. ;;; @@ -18,49 +18,428 @@ (define-module (gnu services) #:use-module (guix gexp) + #:use-module (guix monads) + #:use-module (guix store) #:use-module (guix records) - #:export (service? + #: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-documentation - service-provision - service-requirement - service-respawn? - service-start - service-stop - service-auto-start? - service-activate - service-user-accounts - service-user-groups - service-pam-services)) - -;;; Commentary: + 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." ;;; -;;; System services as cajoled by dmd. +;;; 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> - service make-service +(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? - (documentation service-documentation ; string - (default "[No documentation.]")) - (provision service-provision) ; list of symbols - (requirement service-requirement ; list of symbols - (default '())) - (respawn? service-respawn? ; Boolean - (default #t)) - (start service-start) ; g-expression (procedure) - (stop service-stop ; g-expression (procedure) - (default #~(const #f))) - (auto-start? service-auto-start? ; Boolean - (default #t)) - (user-accounts service-user-accounts ; list of <user-account> - (default '())) - (user-groups service-user-groups ; list of <user-groups> - (default '())) - (pam-services service-pam-services ; list of <pam-service> - (default '())) - (activate service-activate ; gexp - (default #f))) + (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. |