Toggle diff (324 lines)
diff --git a/doc/guix.texi b/doc/guix.texi
index 53b0ebd1db..35da58e59f 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -35718,6 +35718,15 @@ Virtualization Services
The default configuration (see @code{hurd-vm-configuration} below)
spawns a secure shell (SSH) server in your GNU/Hurd system, which QEMU
(the virtual machine emulator) redirects to port 10222 on the host.
+By default, the service enables @dfn{offloading} such that the host
+@code{guix-daemon} automatically offloads GNU/Hurd builds to the
+childhurd (@pxref{Daemon Offload Setup}). This is what happens when
+running a command like the following one, where @code{i586-gnu} is the
+system type of 32-bit GNU/Hurd:
+
+@example
+guix build emacs-minimal -s i586-gnu
+@end example
The childhurd is volatile and stateless: it starts with a fresh root
file system every time you restart it. By default though, all the files
@@ -35851,6 +35860,41 @@ Virtualization Services
@var{vnc-port}: @code{(+ 15900 (* 1000 @var{ID}))}
@end example
+@cindex childhurd, offloading
+@cindex Hurd, offloading
+@item @code{offloading?} (default: @code{#t})
+Whether to automatically set up offloading of builds to the childhurd.
+
+When enabled, this lets you run GNU/Hurd builds on the host and have
+them transparently offloaded to the VM, for instance when running a
+command like this:
+
+@example
+guix build coreutils -s i586-gnu
+@end example
+
+This option automatically sets up offloading like so:
+
+@enumerate
+@item
+Authorizing the childhurd's key on the host so that the host accepts
+build results coming from the childhurd, which can be done like so
+(@pxref{Invoking guix archive, @command{guix archive --authorize}}, for
+more on that).
+
+@item
+Creating a user account called @code{offloading} dedicated to offloading
+in the childhurd.
+
+@item
+Creating an SSH key pair on the host and making it an authorized key of
+the @code{offloading} account in the childhurd.
+
+@item
+Adding the childhurd to @file{/etc/guix/machines.scm} (@pxref{Daemon
+Offload Setup}).
+@end enumerate
+
@item @code{secret-root} (default: @file{/etc/childhurd})
The root directory with out-of-band secrets to be installed into the
childhurd once it runs. Childhurds are volatile which means that on
@@ -35868,38 +35912,13 @@ Virtualization Services
/etc/childhurd/etc/guix/acl
/etc/childhurd/etc/guix/signing-key.pub
/etc/childhurd/etc/guix/signing-key.sec
+/etc/childhurd/etc/ssh/authorized_keys.d/offloading
/etc/childhurd/etc/ssh/ssh_host_ed25519_key
/etc/childhurd/etc/ssh/ssh_host_ecdsa_key
/etc/childhurd/etc/ssh/ssh_host_ed25519_key.pub
/etc/childhurd/etc/ssh/ssh_host_ecdsa_key.pub
@end example
-These files are automatically sent to the guest Hurd VM when it boots,
-including permissions.
-
-@cindex childhurd, offloading
-@cindex Hurd, offloading
-Having these files in place means that only a couple of things are
-missing to allow the host to offload @code{i586-gnu} builds to the
-childhurd:
-
-@enumerate
-@item
-Authorizing the childhurd's key on the host so that the host accepts
-build results coming from the childhurd, which can be done like so:
-
-@example
-guix archive --authorize < \
- /etc/childhurd/etc/guix/signing-key.pub
-@end example
-
-@item
-Adding the childhurd to @file{/etc/guix/machines.scm} (@pxref{Daemon
-Offload Setup}).
-@end enumerate
-
-We're working towards making that happen automatically---get in touch
-with us at @email{guix-devel@@gnu.org} to discuss it!
@end table
@end deftp
diff --git a/gnu/services/virtualization.scm b/gnu/services/virtualization.scm
index 930c2ce702..076eca7ea2 100644
--- a/gnu/services/virtualization.scm
+++ b/gnu/services/virtualization.scm
@@ -27,6 +27,7 @@ (define-module (gnu services virtualization)
#:use-module (gnu bootloader grub)
#:use-module (gnu image)
#:use-module (gnu packages admin)
+ #:use-module (gnu packages bash)
#:use-module (gnu packages gdb)
#:autoload (gnu packages gnupg) (guile-gcrypt)
#:use-module (gnu packages package-management)
@@ -52,6 +53,7 @@ (define-module (gnu services virtualization)
#:use-module (guix store)
#:use-module (guix utils)
#:autoload (guix self) (make-config.scm)
+ #:autoload (guix platform) (platform-system)
#:use-module (srfi srfi-9)
#:use-module (srfi srfi-26)
@@ -1063,6 +1065,26 @@ (define (secret-service-operating-system os)
;;; The Hurd in VM service: a Childhurd.
;;;
+(define (operating-system-with-offloading-account os)
+ (define accounts
+ (list (user-group
+ (name "offloading")
+ (system? #t))
+ (user-account
+ (name "offloading")
+ (group "offloading")
+ (system? #t)
+ (comment "Offloading privilege separation user")
+ (home-directory "/var/run/offloading")
+ (shell (file-append bash-minimal "/bin/sh")))))
+
+ (operating-system
+ (inherit os)
+ (services (cons (simple-service 'offloading-account
+ account-service-type
+ accounts)
+ (operating-system-user-services os)))))
+
(define %hurd-vm-operating-system
(operating-system
(inherit %hurd-default-operating-system)
@@ -1115,14 +1137,21 @@ (define-record-type* <hurd-vm-configuration>
(net-options hurd-vm-configuration-net-options ;list of string
(thunked)
(default (hurd-vm-net-options this-record)))
+ (offloading? hurd-vm-configuration-offloading? ;Boolean
+ (default #t))
(secret-root hurd-vm-configuration-secret-root ;string
(default "/etc/childhurd")))
(define (hurd-vm-disk-image config)
"Return a disk-image for the Hurd according to CONFIG. The secret-service
is added to the OS specified in CONFIG."
- (let* ((os (secret-service-operating-system
- (hurd-vm-configuration-os config)))
+ (define transform
+ (compose secret-service-operating-system
+ (if (hurd-vm-configuration-offloading? config)
+ operating-system-with-offloading-account
+ identity)))
+
+ (let* ((os (transform (hurd-vm-configuration-os config)))
(disk-size (hurd-vm-configuration-disk-size config))
(type (lookup-image-type-by-name 'hurd-qcow2))
(os->image (image-type-constructor type)))
@@ -1331,18 +1360,71 @@ (define (hurd-vm-activation config)
(define guix-directory
(string-append secret-directory "/etc/guix"))
+ (define offloading-ssh-key
+ #$(hurd-vm-configuration-offloading-ssh-key config))
+
(unless (file-exists? ssh-directory)
;; Generate SSH host keys under SSH-DIRECTORY.
(mkdir-p ssh-directory)
(invoke #$(file-append openssh "/bin/ssh-keygen")
"-A" "-f" secret-directory))
+ (unless (or (not #$(hurd-vm-configuration-offloading? config))
+ (file-exists? offloading-ssh-key))
+ ;; Generate a user SSH key pair for the host to use when offloading
+ ;; to the guest.
+ (mkdir-p (dirname offloading-ssh-key))
+ (invoke #$(file-append openssh "/bin/ssh-keygen")
+ "-t" "ed25519" "-N" ""
+ "-f" offloading-ssh-key)
+
+ ;; Authorize it in the guest for user 'offloading'.
+ (let ((authorizations
+ (string-append ssh-directory
+ "/authorized_keys.d/offloading")))
+ (mkdir-p (dirname authorizations))
+ (copy-file (string-append offloading-ssh-key ".pub")
+ authorizations)
+ (chmod (dirname authorizations) #o555)))
+
(unless (file-exists? guix-directory)
(invoke #$(initialize-hurd-vm-substitutes)
guix-directory))
- ;; Authorize the archive signing key from GUIX-DIRECTORY in the host.
- (invoke #$(authorize-guest-substitutes-on-host) guix-directory))))
+ (when #$(hurd-vm-configuration-offloading? config)
+ ;; Authorize the archive signing key from GUIX-DIRECTORY in the host.
+ (invoke #$(authorize-guest-substitutes-on-host) guix-directory)))))
+
+(define (hurd-vm-configuration-offloading-ssh-key config)
+ "Return the name of the file containing the SSH key of user 'offloading'."
+ (string-append "/etc/guix/offload/ssh/childhurd"
+ (or (and=> (hurd-vm-configuration-id config)
+ number->string)
+ "")))
+
+(define (hurd-vm-guix-extension config)
+ "When offloading is enabled, add this childhurd to the list of offlading
+machines in /etc/guix/machines.scm."
+ (if (hurd-vm-configuration-offloading? config)
+ (let* ((image (hurd-vm-configuration-image config))
+ (platform (image-platform image))
+ (system (platform-system platform))
+ (vm-ssh-key (string-append
+ (hurd-vm-configuration-secret-root config)
+ "/etc/ssh/ssh_host_ed25519_key.pub"))
+ (host-ssh-key (hurd-vm-configuration-offloading-ssh-key config)))
+ (guix-extension
+ (build-machines
+ (list #~(build-machine
+ (name "localhost")
+ (port #$(hurd-vm-port config %hurd-vm-ssh-port))
+ (systems '(#$system))
+ (host-key (call-with-input-file #$vm-ssh-key
+ (@ (ice-9 textual-ports)
+ get-string-all)))
+ (user "offloading")
+ (private-key #$host-ssh-key))))))
+ (guix-extension)))
(define hurd-vm-service-type
(service-type
@@ -1351,6 +1433,8 @@ (define hurd-vm-service-type
hurd-vm-shepherd-service)
(service-extension account-service-type
(const %hurd-vm-accounts))
+ (service-extension guix-service-type
+ hurd-vm-guix-extension)
(service-extension activation-service-type
hurd-vm-activation)))
(default-value (hurd-vm-configuration))
diff --git a/gnu/tests/virtualization.scm b/gnu/tests/virtualization.scm
index 599e58edf0..b79164737b 100644
--- a/gnu/tests/virtualization.scm
+++ b/gnu/tests/virtualization.scm
@@ -38,6 +38,7 @@ (define-module (gnu tests virtualization)
#:use-module (guix gexp)
#:use-module (guix records)
#:use-module (guix store)
+ #:use-module (guix modules)
#:export (%test-libvirt
%test-qemu-guest-agent
%test-childhurd))
@@ -244,11 +245,19 @@ (define %childhurd-os
(permit-root-login #t)))))))))))
(define (run-childhurd-test)
+ (define (import-module? module)
+ ;; This module is optional and depends on Guile-Gcrypt, do skip it.
+ (and (guix-module-name? module)
+ (not (equal? module '(guix store deduplication)))))
+
(define os
(marionette-operating-system
%childhurd-os
- #:imported-modules '((gnu services herd)
- (guix combinators))))
+ #:imported-modules (source-module-closure
+ '((gnu services herd)
+ (guix combinators)
+ (gnu build install))
+ #:select? import-module?)))
(define vm
(virtual-machine
@@ -373,6 +382,31 @@ (define (run-childhurd-test)
(pk 'drv (string-trim-right drv)))
drv)))
+ (test-assert "copy-on-write store"
+ ;; Set up a writable store. The root partition is already an
+ ;; overlayfs, which is not suitable as the bottom part of this
+ ;; additional overlayfs; thus, create a tmpfs for the backing
+ ;; store.
+ ;; TODO: Remove this when <virtual-machine> creates a writable
+ ;; store.
+ (marionette-eval
+ '(begin
+ (use-modules (gnu build install)
+ (guix build syscalls))
+
+ (mkdir "/run/writable-store")
+ (mount "none" "/run/writable-store" "tmpfs")
+ (mount-cow-store "/run/writable-store" "/backing-store")
+ (system* "df" "-hT"))
+ marionette))
+
+ (test-equal "offloading"
+ 0
+ (marionette-eval
+ '(and (file-exists? "/etc/guix/machines.scm")
+ (system* "guix" "offload" "test"))
+ marionette))
+
(test-end))))
(gexp->derivation "childhurd-test" test))
--
2.41.0
