services: shepherd: Add 'shepherd-service-upgrade', from 'guix system'.

* guix/scripts/system.scm (service-upgrade): Move to...
* gnu/services/shepherd.scm (shepherd-service-upgrade): ... here.
* tests/system.scm ("service-upgrade: nothing to do", "service-upgrade:
one unchanged, one upgraded, one new", "service-upgrade: service
depended on is not unloaded", "service-upgrade: obsolete services that
depend on each other"): Move to...
* tests/services.scm: ... here.  Adjust to 'service-upgrade' rename.
This commit is contained in:
Ludovic Courtès 2016-08-31 15:40:00 +02:00
parent d4f8884fdb
commit 7b44cae50a
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4 changed files with 121 additions and 118 deletions

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@ -25,6 +25,7 @@
#: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)
@ -53,7 +54,8 @@
shepherd-service-file
shepherd-service-lookup-procedure
shepherd-service-back-edges))
shepherd-service-back-edges
shepherd-service-upgrade))
;;; Commentary:
;;;
@ -293,4 +295,52 @@ symbols provided/required by a service."
(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
needs to be loaded."
(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 (stopped service)
(match (lookup-live (shepherd-service-canonical-name service))
(#f #f)
(service (and (not (live-service-running service))
service))))
(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-load
;; Only load services that are either new or currently stopped.
(remove running? target))
(define to-unload
;; Unload services that are (1) no longer required, or (2) are in TO-LOAD.
(remove essential?
(append (filter obsolete? live)
(filter-map stopped to-load))))
(values to-unload to-load))
;;; shepherd.scm ends here

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@ -272,54 +272,6 @@ on service '~a':~%")
((not error) ;not an error
#t)))
(define (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
needs to be loaded."
(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 (stopped service)
(match (lookup-live (shepherd-service-canonical-name service))
(#f #f)
(service (and (not (live-service-running service))
service))))
(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-load
;; Only load services that are either new or currently stopped.
(remove running? target))
(define to-unload
;; Unload services that are (1) no longer required, or (2) are in TO-LOAD.
(remove essential?
(append (filter obsolete? live)
(filter-map stopped to-load))))
(values to-unload to-load))
(define (call-with-service-upgrade-info new-services mproc)
"Call MPROC, a monadic procedure in %STORE-MONAD, passing it the list of
names of services to load (upgrade), and the list of names of services to
@ -327,7 +279,7 @@ unload."
(match (current-services)
((services ...)
(let-values (((to-unload to-load)
(service-upgrade services new-services)))
(shepherd-service-upgrade services new-services)))
(mproc to-load
(map (compose first live-service-provision)
to-unload))))

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@ -18,12 +18,17 @@
(define-module (test-services)
#:use-module (gnu services)
#:use-module (gnu services herd)
#:use-module (gnu services shepherd)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-26)
#:use-module (srfi srfi-34)
#:use-module (srfi srfi-64))
(define live-service
(@@ (gnu services herd) live-service))
(test-begin "services")
(test-assert "service-back-edges"
@ -127,4 +132,67 @@
(lset= eq? (e s2) (list s3))
(null? (e s3)))))
(test-equal "shepherd-service-upgrade: nothing to do"
'(() ())
(call-with-values
(lambda ()
(shepherd-service-upgrade '() '()))
list))
(test-equal "shepherd-service-upgrade: one unchanged, one upgraded, one new"
'(((bar)) ;unload
((bar) (baz))) ;load
(call-with-values
(lambda ()
;; Here 'foo' is not upgraded because it is still running, whereas
;; 'bar' is upgraded because it is not currently running. 'baz' is
;; loaded because it's a new service.
(shepherd-service-upgrade
(list (live-service '(foo) '() #t)
(live-service '(bar) '() #f)
(live-service '(root) '() #t)) ;essential!
(list (shepherd-service (provision '(foo))
(start #t))
(shepherd-service (provision '(bar))
(start #t))
(shepherd-service (provision '(baz))
(start #t)))))
(lambda (unload load)
(list (map live-service-provision unload)
(map shepherd-service-provision load)))))
(test-equal "shepherd-service-upgrade: service depended on is not unloaded"
'(((baz)) ;unload
()) ;load
(call-with-values
(lambda ()
;; Service 'bar' is not among the target services; yet, it must not be
;; unloaded because 'foo' depends on it.
(shepherd-service-upgrade
(list (live-service '(foo) '(bar) #t)
(live-service '(bar) '() #t) ;still used!
(live-service '(baz) '() #t))
(list (shepherd-service (provision '(foo))
(start #t)))))
(lambda (unload load)
(list (map live-service-provision unload)
(map shepherd-service-provision load)))))
(test-equal "shepherd-service-upgrade: obsolete services that depend on each other"
'(((foo) (bar) (baz)) ;unload
((qux))) ;load
(call-with-values
(lambda ()
;; 'foo', 'bar', and 'baz' depend on each other, but all of them are
;; obsolete, and thus should be unloaded.
(shepherd-service-upgrade
(list (live-service '(foo) '(bar) #t) ;obsolete
(live-service '(bar) '(baz) #t) ;obsolete
(live-service '(baz) '() #t)) ;obsolete
(list (shepherd-service (provision '(qux))
(start #t)))))
(lambda (unload load)
(list (map live-service-provision unload)
(map shepherd-service-provision load)))))
(test-end)

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@ -19,8 +19,6 @@
(define-module (test-system)
#:use-module (gnu)
#:use-module (guix store)
#:use-module (gnu services herd)
#:use-module (gnu services shepherd)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-64))
@ -61,12 +59,7 @@
%base-file-systems))
(users %base-user-accounts)))
(define live-service
(@@ (gnu services herd) live-service))
(define service-upgrade
(@@ (guix scripts system) service-upgrade))
(test-begin "system")
(test-assert "operating-system-store-file-system"
@ -121,64 +114,4 @@
(type "ext4"))
%base-file-systems)))))
(test-equal "service-upgrade: nothing to do"
'(() ())
(call-with-values
(lambda ()
(service-upgrade '() '()))
list))
(test-equal "service-upgrade: one unchanged, one upgraded, one new"
'(((bar)) ;unload
((bar) (baz))) ;load
(call-with-values
(lambda ()
;; Here 'foo' is not upgraded because it is still running, whereas
;; 'bar' is upgraded because it is not currently running. 'baz' is
;; loaded because it's a new service.
(service-upgrade (list (live-service '(foo) '() #t)
(live-service '(bar) '() #f)
(live-service '(root) '() #t)) ;essential!
(list (shepherd-service (provision '(foo))
(start #t))
(shepherd-service (provision '(bar))
(start #t))
(shepherd-service (provision '(baz))
(start #t)))))
(lambda (unload load)
(list (map live-service-provision unload)
(map shepherd-service-provision load)))))
(test-equal "service-upgrade: service depended on is not unloaded"
'(((baz)) ;unload
()) ;load
(call-with-values
(lambda ()
;; Service 'bar' is not among the target services; yet, it must not be
;; unloaded because 'foo' depends on it.
(service-upgrade (list (live-service '(foo) '(bar) #t)
(live-service '(bar) '() #t) ;still used!
(live-service '(baz) '() #t))
(list (shepherd-service (provision '(foo))
(start #t)))))
(lambda (unload load)
(list (map live-service-provision unload)
(map shepherd-service-provision load)))))
(test-equal "service-upgrade: obsolete services that depend on each other"
'(((foo) (bar) (baz)) ;unload
((qux))) ;load
(call-with-values
(lambda ()
;; 'foo', 'bar', and 'baz' depend on each other, but all of them are
;; obsolete, and thus should be unloaded.
(service-upgrade (list (live-service '(foo) '(bar) #t) ;obsolete
(live-service '(bar) '(baz) #t) ;obsolete
(live-service '(baz) '() #t)) ;obsolete
(list (shepherd-service (provision '(qux))
(start #t)))))
(lambda (unload load)
(list (map live-service-provision unload)
(map shepherd-service-provision load)))))
(test-end)