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[bug#33508] [PATCH] gnu: Add ability to restart services on system recon
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From: |
Carlo Zancanaro |
|
Subject: |
[bug#33508] [PATCH] gnu: Add ability to restart services on system reconfigure |
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Date: |
Sat, 01 Dec 2018 13:31:48 +1100 |
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User-agent: |
mu4e 1.0; emacs 26.1 |
Hey Clément,
I'm still working through my thoughts on how all of this should
work. I feel like there are a few different use-cases that change
the trade-offs (eg. servers vs desktops, multi-user vs
single-user) and I don't know what the best defaults are, or the
most useful ways to vary that behaviour.
I've attached my most recent version of my patches. I haven't had
a chance to test them (so they may have really dumb mistakes), but
they should implement the idea of restart-actions as procedures.
On Fri, Nov 30 2018, Clément Lassieur wrote:
It could also detect whether you pass a symbol or a procedure.
In most cases that would be a symbol which would allow static
analysis. But one could still customize it with a procedure.
I don't like this way of having two different representations for
the same thing. In my current implementation there are three
procedures, {always,manually,never}-restart, which can be used
directly in the place of the old symbols (thus we can check for
those strategies with eq?).
Carlo
>From 25d631b33b84f1f48bc06a192c46eb3170e29b97 Mon Sep 17 00:00:00 2001
From: Carlo Zancanaro <address@hidden>
Date: Mon, 26 Nov 2018 22:38:08 +1100
Subject: [PATCH 1/3] gnu: Add ability to restart services on system
reconfigure
* gnu/services/herd.scm (restart-service): New procedure.
* gnu/services/shepherd.scm (<shepherd-service>)[restart-strategy]: New
field.
(always-restart, manually-restart, never-restart): New procedures.
* guix/scripts/system.scm (upgrade-shepherd-services): Automatically restart
services that should be automatically restarted, and print a message about
manually restarting services that should be manually restarted.
Temporary commit
---
gnu/services/herd.scm | 5 +++++
gnu/services/shepherd.scm | 25 ++++++++++++++++++++++++-
guix/scripts/system.scm | 37 +++++++++++++++++++++++++------------
3 files changed, 54 insertions(+), 13 deletions(-)
diff --git a/gnu/services/herd.scm b/gnu/services/herd.scm
index 8ff817759..c8d6eb04e 100644
--- a/gnu/services/herd.scm
+++ b/gnu/services/herd.scm
@@ -52,6 +52,7 @@
load-services
load-services/safe
start-service
+ restart-service
stop-service))
;;; Commentary:
@@ -256,6 +257,10 @@ when passed a service with an already-registered name."
(with-shepherd-action name ('start) result
result))
+(define (restart-service name)
+ (with-shepherd-action name ('restart) result
+ result))
+
(define (stop-service name)
(with-shepherd-action name ('stop) result
result))
diff --git a/gnu/services/shepherd.scm b/gnu/services/shepherd.scm
index 49d08cc30..f7e690fb0 100644
--- a/gnu/services/shepherd.scm
+++ b/gnu/services/shepherd.scm
@@ -44,12 +44,17 @@
shepherd-service-provision
shepherd-service-canonical-name
shepherd-service-requirement
+ shepherd-service-restart-strategy
shepherd-service-respawn?
shepherd-service-start
shepherd-service-stop
shepherd-service-auto-start?
shepherd-service-modules
+ always-restart
+ manually-restart
+ never-restart
+
shepherd-action
shepherd-action?
shepherd-action-name
@@ -141,6 +146,22 @@ DEFAULT is given, use it as the service's default value."
(guix build utils)
(guix build syscalls)))
+(define (always-restart service)
+ "Unconditionally restart SERVICE and return #f."
+ (let ((name (shepherd-service-canonical-name service)))
+ (info (G_ "restarting service: ~a~%") name)
+ (restart-service name)
+ #f))
+
+(define (manually-restart service)
+ "Do not restart SERVICE, but return #t to indicate that the user should
+restart it."
+ #t)
+
+(define (never-restart service)
+ "Do not restart SERVICE and return #f."
+ #f)
+
(define-record-type* <shepherd-service>
shepherd-service make-shepherd-service
shepherd-service?
@@ -159,7 +180,9 @@ DEFAULT is given, use it as the service's default value."
(auto-start? shepherd-service-auto-start? ;Boolean
(default #t))
(modules shepherd-service-modules ;list of module names
- (default %default-modules)))
+ (default %default-modules))
+ (restart-strategy shepherd-service-restart-strategy ;procedure
+ (default manually-restart)))
(define-record-type* <shepherd-action>
shepherd-action make-shepherd-action
diff --git a/guix/scripts/system.scm b/guix/scripts/system.scm
index d92ec7d5a..26e35fe99 100644
--- a/guix/scripts/system.scm
+++ b/guix/scripts/system.scm
@@ -355,16 +355,14 @@ bring the system down."
(with-monad %store-monad
(munless (null? new-services)
- (let ((new-service-names (map shepherd-service-canonical-name
new-services))
- (to-restart-names (map shepherd-service-canonical-name
to-restart))
- (to-start (filter shepherd-service-auto-start?
new-services)))
- (info (G_ "loading new services:~{ ~a~}...~%") new-service-names)
- (unless (null? to-restart-names)
- ;; Listing TO-RESTART-NAMES in the message below wouldn't help
- ;; because many essential services cannot be meaningfully
- ;; restarted. See
<https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22039#30>.
- (format #t (G_ "To complete the upgrade, run 'herd restart
SERVICE' to stop,
-upgrade, and restart each service that was not automatically restarted.\n")))
+ (let* ((new-service-names (map shepherd-service-canonical-name
new-services))
+ (to-restart-names (map shepherd-service-canonical-name
to-restart))
+ (to-start-names (map shepherd-service-canonical-name
+ (filter (lambda (service)
+ (and
(shepherd-service-auto-start? service)
+ (not (member service
to-restart))))
+ new-services))))
+
(mlet %store-monad ((files (mapm %store-monad
(compose lower-object
shepherd-service-file)
@@ -372,10 +370,25 @@ upgrade, and restart each service that was not
automatically restarted.\n")))
;; Here we assume that FILES are exactly those that were
computed
;; as part of the derivation that built OS, which is normally
the
;; case.
+ (info (G_ "loading new services:~{ ~a~}~%") new-service-names)
(load-services/safe (map derivation->output-path files))
- (for-each start-service
- (map shepherd-service-canonical-name to-start))
+ (info (G_ "starting services:~{ ~a~}~%") to-start-names)
+ (for-each (lambda (service-name)
+ (info (G_ "starting service: ~a~%") service-name)
+ (start-service service-name))
+ to-start-names)
+
+ (let* ((to-manually-restart (filter (lambda (service)
+
((shepherd-service-restart-strategy service)
+ service))
+ to-restart))
+ (to-manually-restart-names (map
shepherd-service-canonical-name
+ to-manually-restart)))
+ (unless (null? to-manually-restart-names)
+ (info (G_ "To complete the upgrade, the following services
need to be manually restarted:~{ ~a~}~%")
+ to-manually-restart-names)))
+
(return #t)))))))))
(define* (switch-to-system os
--
2.19.2
>From 270a126c6efd498798bb9342a12c0f671df51b4c Mon Sep 17 00:00:00 2001
From: Carlo Zancanaro <address@hidden>
Date: Mon, 26 Nov 2018 22:38:18 +1100
Subject: [PATCH 2/3] system: Add --restart-services flag for reconfigure
* gnu/services/shepherd.scm (always-restart, manually-restart, never-restart):
Add restart-services? argument.
* guix/scripts/system.scm (upgrade-shepherd-services): Add parameter to
automatically restart services marked as needing manual restart.
(switch-to-system, perform-action, process-action): Pass through
restart-services? flag.
(%options): Add --restart-services flag.
(%default-options): Add #f as default value for --restart-services flag.
---
gnu/services/shepherd.scm | 14 ++++++++------
guix/scripts/system.scm | 23 +++++++++++++++--------
2 files changed, 23 insertions(+), 14 deletions(-)
diff --git a/gnu/services/shepherd.scm b/gnu/services/shepherd.scm
index f7e690fb0..638f6440c 100644
--- a/gnu/services/shepherd.scm
+++ b/gnu/services/shepherd.scm
@@ -146,19 +146,21 @@ DEFAULT is given, use it as the service's default value."
(guix build utils)
(guix build syscalls)))
-(define (always-restart service)
+(define (always-restart service restart-services?)
"Unconditionally restart SERVICE and return #f."
(let ((name (shepherd-service-canonical-name service)))
(info (G_ "restarting service: ~a~%") name)
(restart-service name)
#f))
-(define (manually-restart service)
- "Do not restart SERVICE, but return #t to indicate that the user should
-restart it."
- #t)
+(define (manually-restart service restart-services?)
+ "Restart SERVICE and return #f if RESTART-SERVICES? is true, otherwise
return #t to
+indicate that the user should manually restart SERVICE."
+ (if restart-services?
+ (always-restart service #t)
+ #t))
-(define (never-restart service)
+(define (never-restart service restart-services?)
"Do not restart SERVICE and return #f."
#f)
diff --git a/guix/scripts/system.scm b/guix/scripts/system.scm
index 26e35fe99..7c2699065 100644
--- a/guix/scripts/system.scm
+++ b/guix/scripts/system.scm
@@ -332,7 +332,7 @@ unload."
(warning (G_ "failed to obtain list of shepherd services~%"))
(return #f)))))
-(define (upgrade-shepherd-services os)
+(define (upgrade-shepherd-services os restart-services?)
"Upgrade the Shepherd (PID 1) by unloading obsolete services and loading new
services specified in OS and not currently running.
@@ -381,7 +381,8 @@ bring the system down."
(let* ((to-manually-restart (filter (lambda (service)
((shepherd-service-restart-strategy service)
- service))
+ service
+ restart-services?))
to-restart))
(to-manually-restart-names (map
shepherd-service-canonical-name
to-manually-restart)))
@@ -391,7 +392,7 @@ bring the system down."
(return #t)))))))))
-(define* (switch-to-system os
+(define* (switch-to-system os restart-services?
#:optional (profile %system-profile))
"Make a new generation of PROFILE pointing to the directory of OS, switch to
it atomically, and then run OS's activation script."
@@ -419,7 +420,7 @@ it atomically, and then run OS's activation script."
(primitive-load (derivation->output-path script))))
;; Finally, try to update system services.
- (upgrade-shepherd-services os))))
+ (upgrade-shepherd-services os restart-services?))))
(define-syntax-rule (unless-file-not-found exp)
(catch 'system-error
@@ -827,7 +828,8 @@ and TARGET arguments."
use-substitutes? bootloader-target target
image-size file-system-type full-boot?
(mappings '())
- (gc-root #f))
+ (gc-root #f)
+ (restart-services? #f))
"Perform ACTION for OS. INSTALL-BOOTLOADER? specifies whether to install
bootloader; BOOTLOADER-TAGET is the target for the bootloader; TARGET is the
target root directory; IMAGE-SIZE is the size of the image to be built, for
@@ -909,7 +911,7 @@ static checks."
(case action
((reconfigure)
(mbegin %store-monad
- (switch-to-system os)
+ (switch-to-system os restart-services?)
(mwhen install-bootloader?
(install-bootloader bootloader-script
#:bootcfg bootcfg
@@ -1092,6 +1094,9 @@ Some ACTIONS support additional ARGS.\n"))
(option '(#\r "root") #t #f
(lambda (opt name arg result)
(alist-cons 'gc-root arg result)))
+ (option '("restart-services") #f #f
+ (lambda (opt name arg result)
+ (alist-cons 'restart-services? #t result)))
%standard-build-options))
(define %default-options
@@ -1106,7 +1111,8 @@ Some ACTIONS support additional ARGS.\n"))
(verbosity . 0)
(file-system-type . "ext4")
(image-size . guess)
- (install-bootloader? . #t)))
+ (install-bootloader? . #t)
+ (restart-services? . #f)))
;;;
@@ -1179,7 +1185,8 @@ resulting from command-line parsing."
#:install-bootloader? bootloader?
#:target target
#:bootloader-target bootloader-target
- #:gc-root (assoc-ref opts 'gc-root)))))
+ #:gc-root (assoc-ref opts 'gc-root)
+ #:restart-services? (assoc-ref opts
'restart-services?)))))
#:system system))
(warn-about-disk-space)))
--
2.19.2
>From 2077919dca604c94b09cf105c33987daa8c46304 Mon Sep 17 00:00:00 2001
From: Carlo Zancanaro <address@hidden>
Date: Mon, 26 Nov 2018 22:38:26 +1100
Subject: [PATCH 3/3] services: Always restart guix daemon
* gnu/services/base.scm (guix-shepherd-service): Add restart-strategy of
always-restart.
---
gnu/services/base.scm | 1 +
1 file changed, 1 insertion(+)
diff --git a/gnu/services/base.scm b/gnu/services/base.scm
index 228d3c592..37d60720d 100644
--- a/gnu/services/base.scm
+++ b/gnu/services/base.scm
@@ -1573,6 +1573,7 @@ failed to register hydra.gnu.org public key: ~a~%"
status))))))))
(documentation "Run the Guix daemon.")
(provision '(guix-daemon))
(requirement '(user-processes))
+ (restart-strategy always-restart)
(modules '((srfi srfi-1)))
(start
#~(make-forkexec-constructor
--
2.19.2