408 lines
16 KiB
Scheme
408 lines
16 KiB
Scheme
;;; GNU Guix --- Functional package management for GNU
|
|
;;; Copyright © 2013, 2014, 2015, 2016, 2018, 2019, 2020 Ludovic Courtès <ludo@gnu.org>
|
|
;;; Copyright © 2017 Clément Lassieur <clement@lassieur.org>
|
|
;;; Copyright © 2018 Carlo Zancanaro <carlo@zancanaro.id.au>
|
|
;;;
|
|
;;; 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 shepherd)
|
|
#:use-module (guix ui)
|
|
#:use-module (guix sets)
|
|
#:use-module (guix gexp)
|
|
#:use-module (guix store)
|
|
#:use-module (guix records)
|
|
#:use-module (guix derivations) ;imported-modules, etc.
|
|
#:use-module (gnu services)
|
|
#:use-module (gnu services herd)
|
|
#:use-module (gnu packages admin)
|
|
#:use-module (ice-9 match)
|
|
#:use-module (ice-9 vlist)
|
|
#:use-module (srfi srfi-1)
|
|
#:use-module (srfi srfi-26)
|
|
#:use-module (srfi srfi-34)
|
|
#:use-module (srfi srfi-35)
|
|
#:export (shepherd-root-service-type
|
|
%shepherd-root-service
|
|
shepherd-service-type
|
|
|
|
shepherd-service
|
|
shepherd-service?
|
|
shepherd-service-documentation
|
|
shepherd-service-provision
|
|
shepherd-service-canonical-name
|
|
shepherd-service-requirement
|
|
shepherd-service-one-shot?
|
|
shepherd-service-respawn?
|
|
shepherd-service-start
|
|
shepherd-service-stop
|
|
shepherd-service-auto-start?
|
|
shepherd-service-modules
|
|
|
|
shepherd-action
|
|
shepherd-action?
|
|
shepherd-action-name
|
|
shepherd-action-documentation
|
|
shepherd-action-procedure
|
|
|
|
%default-modules
|
|
|
|
shepherd-service-file
|
|
|
|
shepherd-service-lookup-procedure
|
|
shepherd-service-back-edges
|
|
shepherd-service-upgrade))
|
|
|
|
;;; Commentary:
|
|
;;;
|
|
;;; Instantiating system services as a shepherd configuration file.
|
|
;;;
|
|
;;; Code:
|
|
|
|
|
|
(define (shepherd-boot-gexp services)
|
|
#~(begin
|
|
;; Keep track of the booted system.
|
|
(false-if-exception (delete-file "/run/booted-system"))
|
|
(symlink (readlink "/run/current-system")
|
|
"/run/booted-system")
|
|
|
|
;; Close any remaining open file descriptors to be on the safe
|
|
;; side. This must be the very last thing we do, because
|
|
;; Guile has internal FDs such as 'sleep_pipe' that need to be
|
|
;; alive.
|
|
(let loop ((fd 3))
|
|
(when (< fd 1024)
|
|
(false-if-exception (close-fdes fd))
|
|
(loop (+ 1 fd))))
|
|
|
|
;; Start shepherd.
|
|
(execl #$(file-append shepherd "/bin/shepherd")
|
|
"shepherd" "--config"
|
|
#$(shepherd-configuration-file services))))
|
|
|
|
(define shepherd-root-service-type
|
|
(service-type
|
|
(name 'shepherd-root)
|
|
;; Extending the root shepherd service (aka. PID 1) happens by
|
|
;; concatenating the list of services provided by the extensions.
|
|
(compose concatenate)
|
|
(extend append)
|
|
(extensions (list (service-extension boot-service-type
|
|
shepherd-boot-gexp)
|
|
(service-extension profile-service-type
|
|
(const (list shepherd)))))))
|
|
|
|
(define %shepherd-root-service
|
|
;; The root shepherd service, aka. PID 1. Its parameter is a list of
|
|
;; <shepherd-service> objects.
|
|
(service shepherd-root-service-type '()))
|
|
|
|
(define-syntax shepherd-service-type
|
|
(syntax-rules ()
|
|
"Return a <service-type> denoting a simple shepherd service--i.e., the type
|
|
for a service that extends SHEPHERD-ROOT-SERVICE-TYPE and nothing else. When
|
|
DEFAULT is given, use it as the service's default value."
|
|
((_ service-name proc default)
|
|
(service-type
|
|
(name service-name)
|
|
(extensions
|
|
(list (service-extension shepherd-root-service-type
|
|
(compose list proc))))
|
|
(default-value default)))
|
|
((_ service-name proc)
|
|
(service-type
|
|
(name service-name)
|
|
(extensions
|
|
(list (service-extension shepherd-root-service-type
|
|
(compose list proc))))))))
|
|
|
|
(define %default-imported-modules
|
|
;; Default set of modules imported for a service's consumption.
|
|
'((guix build utils)
|
|
(guix build syscalls)))
|
|
|
|
(define %default-modules
|
|
;; Default set of modules visible in a service's file.
|
|
`((shepherd service)
|
|
(oop goops)
|
|
(guix build utils)
|
|
(guix build syscalls)))
|
|
|
|
(define-record-type* <shepherd-service>
|
|
shepherd-service make-shepherd-service
|
|
shepherd-service?
|
|
(documentation shepherd-service-documentation ;string
|
|
(default "[No documentation.]"))
|
|
(provision shepherd-service-provision) ;list of symbols
|
|
(requirement shepherd-service-requirement ;list of symbols
|
|
(default '()))
|
|
(one-shot? shepherd-service-one-shot? ;Boolean
|
|
(default #f))
|
|
(respawn? shepherd-service-respawn? ;Boolean
|
|
(default #t))
|
|
(start shepherd-service-start) ;g-expression (procedure)
|
|
(stop shepherd-service-stop ;g-expression (procedure)
|
|
(default #~(const #f)))
|
|
(actions shepherd-service-actions ;list of <shepherd-action>
|
|
(default '()))
|
|
(auto-start? shepherd-service-auto-start? ;Boolean
|
|
(default #t))
|
|
(modules shepherd-service-modules ;list of module names
|
|
(default %default-modules)))
|
|
|
|
(define-record-type* <shepherd-action>
|
|
shepherd-action make-shepherd-action
|
|
shepherd-action?
|
|
(name shepherd-action-name) ;symbol
|
|
(procedure shepherd-action-procedure) ;gexp
|
|
(documentation shepherd-action-documentation)) ;string
|
|
|
|
(define (shepherd-service-canonical-name service)
|
|
"Return the 'canonical name' of SERVICE."
|
|
(first (shepherd-service-provision service)))
|
|
|
|
(define (assert-valid-graph services)
|
|
"Raise an error if SERVICES does not define a valid shepherd service graph,
|
|
for instance if a service requires a nonexistent service, or if more than one
|
|
service uses a given name.
|
|
|
|
These are constraints that shepherd's 'register-service' verifies but we'd
|
|
better verify them here statically than wait until PID 1 halts with an
|
|
assertion failure."
|
|
(define provisions
|
|
;; The set of provisions (symbols). Bail out if a symbol is given more
|
|
;; than once.
|
|
(fold (lambda (service set)
|
|
(define (assert-unique symbol)
|
|
(when (set-contains? set symbol)
|
|
(raise (condition
|
|
(&message
|
|
(message
|
|
(format #f (G_ "service '~a' provided more than once")
|
|
symbol)))))))
|
|
|
|
(for-each assert-unique (shepherd-service-provision service))
|
|
(fold set-insert set (shepherd-service-provision service)))
|
|
(setq 'shepherd)
|
|
services))
|
|
|
|
(define (assert-satisfied-requirements service)
|
|
;; Bail out if the requirements of SERVICE aren't satisfied.
|
|
(for-each (lambda (requirement)
|
|
(unless (set-contains? provisions requirement)
|
|
(raise (condition
|
|
(&message
|
|
(message
|
|
(format #f (G_ "service '~a' requires '~a', \
|
|
which is not provided by any service")
|
|
(match (shepherd-service-provision service)
|
|
((head . _) head)
|
|
(_ service))
|
|
requirement)))))))
|
|
(shepherd-service-requirement service)))
|
|
|
|
(for-each assert-satisfied-requirements services))
|
|
|
|
(define (shepherd-service-file-name service)
|
|
"Return the file name where the initialization code for SERVICE is to be
|
|
stored."
|
|
(let ((provisions (string-join (map symbol->string
|
|
(shepherd-service-provision service)))))
|
|
(string-append "shepherd-"
|
|
(string-map (match-lambda
|
|
(#\/ #\-)
|
|
(#\ #\-)
|
|
(chr chr))
|
|
provisions)
|
|
".scm")))
|
|
|
|
(define (shepherd-service-file service)
|
|
"Return a file defining SERVICE."
|
|
(scheme-file (shepherd-service-file-name service)
|
|
(with-imported-modules %default-imported-modules
|
|
#~(begin
|
|
(use-modules #$@(shepherd-service-modules service))
|
|
|
|
(make <service>
|
|
#:docstring '#$(shepherd-service-documentation service)
|
|
#:provides '#$(shepherd-service-provision service)
|
|
#:requires '#$(shepherd-service-requirement service)
|
|
|
|
;; The 'one-shot?' slot is new in Shepherd 0.6.0.
|
|
;; Older versions ignore it.
|
|
#:one-shot? '#$(shepherd-service-one-shot? service)
|
|
|
|
#:respawn? '#$(shepherd-service-respawn? service)
|
|
#:start #$(shepherd-service-start service)
|
|
#:stop #$(shepherd-service-stop service)
|
|
#:actions
|
|
(make-actions
|
|
#$@(map (match-lambda
|
|
(($ <shepherd-action> name proc doc)
|
|
#~(#$name #$doc #$proc)))
|
|
(shepherd-service-actions service))))))))
|
|
|
|
(define (scm->go file)
|
|
"Compile FILE, which contains code to be loaded by shepherd's config file,
|
|
and return the resulting '.go' file."
|
|
(with-extensions (list shepherd)
|
|
(computed-file (string-append (basename (scheme-file-name file) ".scm")
|
|
".go")
|
|
#~(begin
|
|
(use-modules (system base compile))
|
|
|
|
;; Do the same as the Shepherd's 'load-in-user-module'.
|
|
(let ((env (make-fresh-user-module)))
|
|
(module-use! env (resolve-interface '(oop goops)))
|
|
(module-use! env (resolve-interface '(shepherd service)))
|
|
(compile-file #$file #:output-file #$output
|
|
#:env env))))))
|
|
|
|
(define (shepherd-configuration-file services)
|
|
"Return the shepherd configuration file for SERVICES."
|
|
(assert-valid-graph services)
|
|
|
|
(let ((files (map shepherd-service-file services)))
|
|
(define config
|
|
#~(begin
|
|
(use-modules (srfi srfi-34)
|
|
(system repl error-handling))
|
|
|
|
;; Specify the default environment visible to all the services.
|
|
;; Without this statement, all the environment variables of PID 1
|
|
;; are inherited by child services.
|
|
(default-environment-variables
|
|
'("PATH=/run/current-system/profile/bin"))
|
|
|
|
;; Arrange to spawn a REPL if something goes wrong. This is better
|
|
;; than a kernel panic.
|
|
(call-with-error-handling
|
|
(lambda ()
|
|
(apply register-services
|
|
(map load-compiled '#$(map scm->go files)))))
|
|
|
|
(format #t "starting services...~%")
|
|
(for-each (lambda (service)
|
|
;; In the Shepherd 0.3 the 'start' method can raise
|
|
;; '&action-runtime-error' if it fails, so protect
|
|
;; against it. (XXX: 'action-runtime-error?' is not
|
|
;; exported is 0.3, hence 'service-error?'.)
|
|
(guard (c ((service-error? c)
|
|
(format (current-error-port)
|
|
"failed to start service '~a'~%"
|
|
service)))
|
|
(start service)))
|
|
'#$(append-map shepherd-service-provision
|
|
(filter shepherd-service-auto-start?
|
|
services)))
|
|
|
|
;; Hang up stdin. At this point, we assume that 'start' methods
|
|
;; that required user interaction on the console (e.g.,
|
|
;; 'cryptsetup open' invocations, post-fsck emergency REPL) have
|
|
;; completed. User interaction becomes impossible after this
|
|
;; call; this avoids situations where services wrongfully lead
|
|
;; PID 1 to read from stdin (the console), which users may not
|
|
;; have access to (see <https://bugs.gnu.org/23697>).
|
|
(redirect-port (open-input-file "/dev/null")
|
|
(current-input-port))))
|
|
|
|
(scheme-file "shepherd.conf" config)))
|
|
|
|
(define* (shepherd-service-lookup-procedure services
|
|
#:optional
|
|
(provision
|
|
shepherd-service-provision))
|
|
"Return a procedure that, when passed a symbol, return the item among
|
|
SERVICES that provides this symbol. PROVISION must be a one-argument
|
|
procedure that takes a service and returns the list of symbols it provides."
|
|
(let ((services (fold (lambda (service result)
|
|
(fold (cut vhash-consq <> service <>)
|
|
result
|
|
(provision service)))
|
|
vlist-null
|
|
services)))
|
|
(lambda (name)
|
|
(match (vhash-assq name services)
|
|
((_ . service) service)
|
|
(#f #f)))))
|
|
|
|
(define* (shepherd-service-back-edges services
|
|
#:key
|
|
(provision shepherd-service-provision)
|
|
(requirement shepherd-service-requirement))
|
|
"Return a procedure that, when given a <shepherd-service> from SERVICES,
|
|
returns the list of <shepherd-service> that depend on it.
|
|
|
|
Use PROVISION and REQUIREMENT as one-argument procedures that return the
|
|
symbols provided/required by a service."
|
|
(define provision->service
|
|
(shepherd-service-lookup-procedure services provision))
|
|
|
|
(define edges
|
|
(fold (lambda (service edges)
|
|
(fold (lambda (requirement edges)
|
|
(vhash-consq (provision->service requirement) service
|
|
edges))
|
|
edges
|
|
(requirement service)))
|
|
vlist-null
|
|
services))
|
|
|
|
(lambda (service)
|
|
(vhash-foldq* cons '() service edges)))
|
|
|
|
(define (shepherd-service-upgrade live target)
|
|
"Return two values: the subset of LIVE (a list of <live-service>) that needs
|
|
to be unloaded, and the subset of TARGET (a list of <shepherd-service>) that
|
|
need to be restarted to complete their upgrade."
|
|
(define (essential? service)
|
|
(memq (first (live-service-provision service))
|
|
'(root shepherd)))
|
|
|
|
(define lookup-target
|
|
(shepherd-service-lookup-procedure target
|
|
shepherd-service-provision))
|
|
|
|
(define lookup-live
|
|
(shepherd-service-lookup-procedure live
|
|
live-service-provision))
|
|
|
|
(define (running? service)
|
|
(and=> (lookup-live (shepherd-service-canonical-name service))
|
|
live-service-running))
|
|
|
|
(define live-service-dependents
|
|
(shepherd-service-back-edges live
|
|
#:provision live-service-provision
|
|
#:requirement live-service-requirement))
|
|
|
|
(define (obsolete? service)
|
|
(match (lookup-target (first (live-service-provision service)))
|
|
(#f (every obsolete? (live-service-dependents service)))
|
|
(_ #f)))
|
|
|
|
(define to-restart
|
|
;; Restart services that are currently running.
|
|
(filter running? target))
|
|
|
|
(define to-unload
|
|
;; Unload services that are no longer required.
|
|
(remove essential? (filter obsolete? live)))
|
|
|
|
(values to-unload to-restart))
|
|
|
|
;;; shepherd.scm ends here
|