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authorLudovic Courtès <ludo@gnu.org>2015-11-02 18:44:17 +0100
committerLudovic Courtès <ludo@gnu.org>2015-11-02 22:25:11 +0100
commitd62e201cfd0f1e48c14586489d0e2b80ce943d4f (patch)
treed6c4989b36b54f154f21363ac72bd9896729f2de
parent3a391e68dafe81560d3e4936a1ec5ac3b06d43bb (diff)
downloadguix-d62e201cfd0f1e48c14586489d0e2b80ce943d4f.tar.gz
guix-d62e201cfd0f1e48c14586489d0e2b80ce943d4f.zip
services: Add 'system-service-type'.
* gnu/services.scm (system-derivation): New procedure. (system-service-type): New variable. (boot-script-entry): New procedure. (boot-service-type): Extend SYSTEM-SERVICE-TYPE. (etc-entry): New procedure. (etc-service-type): Extend SYSTEM-SERVICE-TYPE. (fold-services): Change default #:target-type to SYSTEM-SERVICE-TYPE. * gnu/system.scm (operating-system-directory-base-entries): New procedure. (essential-services): Use it. Add an instance of SYSTEM-SERVICE-TYPE. (operating-system-boot-script): Pass #:target-type to 'fold-services'. (operating-system-derivation): Rewrite in terms of 'fold-services'. * gnu/system/linux-container.scm (system-container): Remove. (container-script): Use 'operating-system-derivation'. * guix/scripts/system.scm (export-extension-graph): Replace BOOT-SERVICE-TYPE by SYSTEM-SERVICE-TYPE. * doc/images/service-graph.dot: Add 'system' node and edges. * doc/guix.texi (Service Composition): Mention SYSTEM-SERVICE-TYPE. (Service Reference): Document it. Update 'fold-services' documentation.
-rw-r--r--doc/guix.texi26
-rw-r--r--doc/images/service-graph.dot5
-rw-r--r--gnu/services.scm51
-rw-r--r--gnu/system.scm54
-rw-r--r--gnu/system/linux-container.scm18
-rw-r--r--guix/scripts/system.scm6
6 files changed, 103 insertions, 57 deletions
diff --git a/doc/guix.texi b/doc/guix.texi
index 74e0977db5..6ab98deef3 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -7589,8 +7589,11 @@ as arrows, a typical system might provide something like this:
@image{images/service-graph,,5in,Typical service extension graph.}
-At the bottom, we see the @dfn{boot service}, which produces the boot
-script that is executed at boot time from the initial RAM disk.
+@cindex system service
+At the bottom, we see the @dfn{system service}, which produces the
+directory containing everything to run and boot the system, as returned
+by the @command{guix system build} command. @xref{Service Reference},
+to learn about the other service types shown here.
@xref{system-extension-graph, the @command{guix system extension-graph}
command}, for information on how to generate this representation for a
particular operating system definition.
@@ -7853,12 +7856,14 @@ Return true if @var{obj} is a service extension.
At the core of the service abstraction lies the @code{fold-services}
procedure, which is responsible for ``compiling'' a list of services
-down to a single boot script. In essence, it propagates service
-extensions down the service graph, updating each node parameters on the
-way, until it reaches the root node.
+down to a single directory that contains everything needed to boot and
+run the system---the directory shown by the @command{guix system build}
+command (@pxref{Invoking guix system}). In essence, it propagates
+service extensions down the service graph, updating each node parameters
+on the way, until it reaches the root node.
@deffn {Scheme Procedure} fold-services @var{services} @
- [#:target-type @var{boot-service-type}]
+ [#:target-type @var{system-service-type}]
Fold @var{services} by propagating their extensions down to the root of
type @var{target-type}; return the root service adjusted accordingly.
@end deffn
@@ -7866,9 +7871,14 @@ type @var{target-type}; return the root service adjusted accordingly.
Lastly, the @code{(gnu services)} module also defines several essential
service types, some of which are listed below.
+@defvr {Scheme Variable} system-service-type
+This is the root of the service graph. It produces the system directory
+as returned by the @command{guix system build} command.
+@end defvr
+
@defvr {Scheme Variable} boot-service-type
-The type of the ``boot service'', which is the root of the service
-graph.
+The type of the ``boot service'', which produces the @dfn{boot script}.
+The boot script is what the initial RAM disk runs when booting.
@end defvr
@defvr {Scheme Variable} etc-service-type
diff --git a/doc/images/service-graph.dot b/doc/images/service-graph.dot
index 3397b878e9..04f231bb09 100644
--- a/doc/images/service-graph.dot
+++ b/doc/images/service-graph.dot
@@ -4,7 +4,8 @@ digraph "Service Type Dependencies" {
etc [shape = box, fontname = Helvetica];
accounts [shape = box, fontname = Helvetica];
activation [shape = box, fontname = Helvetica];
- boot [shape = house, fontname = Helvetica];
+ boot [shape = box, fontname = Helvetica];
+ system [shape = house, fontname = Helvetica];
lshd -> dmd;
lshd -> pam;
udev -> dmd;
@@ -32,4 +33,6 @@ digraph "Service Type Dependencies" {
guix -> dmd;
guix -> activation;
guix -> accounts;
+ boot -> system;
+ etc -> system;
}
diff --git a/gnu/services.scm b/gnu/services.scm
index ecf3532e52..8a66d453df 100644
--- a/gnu/services.scm
+++ b/gnu/services.scm
@@ -60,6 +60,7 @@
ambiguous-target-service-error-service
ambiguous-target-service-error-target-type
+ system-service-type
boot-service-type
activation-service-type
activation-service->script
@@ -89,9 +90,10 @@
;;; 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.
+;;; A notable service type is SYSTEM-SERVICE-TYPE, which has a single
+;;; instance, which is the root of the service DAG. Its value is the
+;;; derivation that produces the 'system' directory as returned by
+;;; 'operating-system-derivation'.
;;;
;;; The 'fold-services' procedure can be passed a list of procedures, which it
;;; "folds" by propagating extensions down the graph; it returns the root
@@ -182,6 +184,25 @@ This is a shorthand for (map (lambda (svc) ...) %base-services)."
;;; Core services.
;;;
+(define (system-derivation mentries mextensions)
+ "Return as a monadic value the derivation of the 'system' directory
+containing the given entries."
+ (mlet %store-monad ((entries mentries)
+ (extensions (sequence %store-monad mextensions)))
+ (lower-object
+ (file-union "system"
+ (append entries (concatenate extensions))))))
+
+(define system-service-type
+ ;; This is the ultimate service type, the root of the service DAG. The
+ ;; service of this type is extended by monadic name/item pairs. These items
+ ;; end up in the "system directory" as returned by
+ ;; 'operating-system-derivation'.
+ (service-type (name 'system)
+ (extensions '())
+ (compose identity)
+ (extend system-derivation)))
+
(define (compute-boot-script _ mexps)
(mlet %store-monad ((gexps (sequence %store-monad mexps)))
(gexp->file "boot"
@@ -203,17 +224,25 @@ This is a shorthand for (map (lambda (svc) ...) %base-services)."
;; Activate the system and spawn dmd.
#$@gexps))))
+(define (boot-script-entry mboot)
+ "Return, as a monadic value, an entry for the boot script in the system
+directory."
+ (mlet %store-monad ((boot mboot))
+ (return `(("boot" ,boot)))))
+
(define boot-service-type
;; The service of this type is extended by being passed gexps as monadic
;; values. It aggregates them in a single script, as a monadic value, which
;; becomes its 'parameters'. It is the only service that extends nothing.
(service-type (name 'boot)
- (extensions '())
+ (extensions
+ (list (service-extension system-service-type
+ boot-script-entry)))
(compose append)
(extend compute-boot-script)))
(define %boot-service
- ;; This is the ultimate service, the root of the service DAG.
+ ;; The service that produces the boot script.
(service boot-service-type #t))
(define* (file-union name files) ;FIXME: Factorize.
@@ -351,6 +380,12 @@ ACTIVATION-SCRIPT-TYPE."
(define (files->etc-directory files)
(file-union "etc" files))
+(define (etc-entry files)
+ "Return an entry for the /etc directory consisting of FILES in the system
+directory."
+ (with-monad %store-monad
+ (return `(("etc" ,(files->etc-directory files))))))
+
(define etc-service-type
(service-type (name 'etc)
(extensions
@@ -359,7 +394,8 @@ ACTIVATION-SCRIPT-TYPE."
(lambda (files)
(let ((etc
(files->etc-directory files)))
- #~(activate-etc #$etc))))))
+ #~(activate-etc #$etc))))
+ (service-extension system-service-type etc-entry)))
(compose concatenate)
(extend append)))
@@ -450,7 +486,8 @@ kernel."
(lambda (node)
(reverse (vhash-foldq* cons '() node edges)))))
-(define* (fold-services services #:key (target-type boot-service-type))
+(define* (fold-services services
+ #:key (target-type system-service-type))
"Fold SERVICES by propagating their extensions down to the root of type
TARGET-TYPE; return the root service adjusted accordingly."
(define dependents
diff --git a/gnu/system.scm b/gnu/system.scm
index 8fed857b39..c26d27028b 100644
--- a/gnu/system.scm
+++ b/gnu/system.scm
@@ -254,6 +254,24 @@ from the initrd."
"Return the list of swap services for OS."
(map swap-service (operating-system-swap-devices os)))
+(define* (operating-system-directory-base-entries os #:key container?)
+ "Return the basic entries of the 'system' directory of OS for use as the
+value of the SYSTEM-SERVICE-TYPE service."
+ (mlet* %store-monad ((profile (operating-system-profile os))
+ (locale (operating-system-locale-directory os)))
+ (if container?
+ (return `(("profile" ,profile)
+ ("locale" ,locale)))
+ (mlet %store-monad
+ ((kernel -> (operating-system-kernel os))
+ (initrd (operating-system-initrd-file os))
+ (params (operating-system-parameters-file os)))
+ (return `(("kernel" ,kernel)
+ ("parameters" ,params)
+ ("initrd" ,initrd)
+ ("profile" ,profile)
+ ("locale" ,locale))))))) ;used by libc
+
(define* (essential-services os #:key container?)
"Return the list of essential services for OS. These are special services
that implement part of what's declared in OS are responsible for low-level
@@ -269,8 +287,11 @@ a container or that of a \"bare metal\" system."
(swaps (swap-services os))
(procs (user-processes-service
(map service-parameters other-fs)))
- (host-name (host-name-service (operating-system-host-name os))))
- (cons* %boot-service
+ (host-name (host-name-service (operating-system-host-name os)))
+ (entries (operating-system-directory-base-entries
+ os #:container? container?)))
+ (cons* (service system-service-type entries)
+ %boot-service
;; %DMD-ROOT-SERVICE must come first so that the gexp that execs
;; dmd comes last in the boot script (XXX).
@@ -607,10 +628,17 @@ etc."
we're running in the final root. When CONTAINER? is true, skip all
hardware-related operations as necessary when booting a Linux container."
(let* ((services (operating-system-services os #:container? container?))
- (boot (fold-services services)))
+ (boot (fold-services services #:target-type boot-service-type)))
;; BOOT is the script as a monadic value.
(service-parameters boot)))
+(define* (operating-system-derivation os #:key container?)
+ "Return a derivation that builds OS."
+ (let* ((services (operating-system-services os #:container? container?))
+ (system (fold-services services)))
+ ;; SYSTEM contains the derivation as a monadic value.
+ (service-parameters system)))
+
(define (operating-system-root-file-system os)
"Return the root file system of OS."
(find (match-lambda
@@ -693,24 +721,4 @@ this file is the reconstruction of GRUB menu entries for old configurations."
#$(operating-system-kernel-arguments os))
(initrd #$initrd)))))
-(define (operating-system-derivation os)
- "Return a derivation that builds OS."
- (mlet* %store-monad
- ((profile (operating-system-profile os))
- (etc -> (operating-system-etc-directory os))
- (boot (operating-system-boot-script os))
- (kernel -> (operating-system-kernel os))
- (initrd (operating-system-initrd-file os))
- (locale (operating-system-locale-directory os))
- (params (operating-system-parameters-file os)))
- (lower-object
- (file-union "system"
- `(("boot" ,#~#$boot)
- ("kernel" ,#~#$kernel)
- ("parameters" ,#~#$params)
- ("initrd" ,initrd)
- ("profile" ,#~#$profile)
- ("locale" ,#~#$locale) ;used by libc
- ("etc" ,#~#$etc))))))
-
;;; system.scm ends here
diff --git a/gnu/system/linux-container.scm b/gnu/system/linux-container.scm
index c2eb773931..4f38c5cb0a 100644
--- a/gnu/system/linux-container.scm
+++ b/gnu/system/linux-container.scm
@@ -47,20 +47,6 @@
(check? #f)
(create-mount-point? #t)))))
-(define (system-container os)
- "Return a derivation that builds OS as a Linux container."
- (mlet* %store-monad
- ((profile (operating-system-profile os))
- (etc -> (operating-system-etc-directory os))
- (boot (operating-system-boot-script os #:container? #t))
- (locale (operating-system-locale-directory os)))
- (lower-object
- (file-union "system-container"
- `(("boot" ,#~#$boot)
- ("profile" ,#~#$profile)
- ("locale" ,#~#$locale)
- ("etc" ,#~#$etc))))))
-
(define (containerized-operating-system os mappings)
"Return an operating system based on OS for use in a Linux container
environment. MAPPINGS is a list of <file-system-mapping> to realize in the
@@ -95,7 +81,9 @@ that will be shared with the host system."
(operating-system-file-systems os)))
(specs (map file-system->spec file-systems)))
- (mlet* %store-monad ((os-drv (system-container os)))
+ (mlet* %store-monad ((os-drv (operating-system-derivation
+ os
+ #:container? #t)))
(define script
#~(begin
diff --git a/guix/scripts/system.scm b/guix/scripts/system.scm
index 7be734785a..7a8a751df9 100644
--- a/guix/scripts/system.scm
+++ b/guix/scripts/system.scm
@@ -491,10 +491,10 @@ building anything."
(define (export-extension-graph os port)
"Export the service extension graph of OS to PORT."
(let* ((services (operating-system-services os))
- (boot (find (lambda (service)
- (eq? (service-kind service) boot-service-type))
+ (system (find (lambda (service)
+ (eq? (service-kind service) system-service-type))
services)))
- (export-graph (list boot) (current-output-port)
+ (export-graph (list system) (current-output-port)
#:node-type (service-node-type services)
#:reverse-edges? #t)))