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;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2013, 2014 Ludovic Courtès <ludo@gnu.org>
;;;
;;; 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 (guix build vm)
#:use-module (guix build utils)
#:use-module (guix build linux-initrd)
#:use-module (ice-9 match)
#:use-module (ice-9 rdelim)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-26)
#:export (load-in-linux-vm
initialize-hard-disk))
;;; Commentary:
;;;
;;; This module provides supporting code to run virtual machines and build
;;; virtual machine images using QEMU.
;;;
;;; Code:
(define (qemu-command)
"Return the default name of the QEMU command for the current host."
(string-append "qemu-system-"
(substring %host-type 0
(string-index %host-type #\-))))
(define* (load-in-linux-vm builder
#:key
output
(qemu (qemu-command)) (memory-size 512)
linux initrd
make-disk-image? (disk-image-size 100)
(references-graphs '()))
"Run BUILDER, a Scheme file, into a VM running LINUX with INITRD, and copy
the result to OUTPUT.
When MAKE-DISK-IMAGE? is true, OUTPUT will contain a VM image of
DISK-IMAGE-SIZE MiB resulting from the execution of BUILDER, which may access
it via /dev/hda.
REFERENCES-GRAPHS can specify a list of reference-graph files as produced by
the #:references-graphs parameter of 'derivation'."
(when make-disk-image?
(unless (zero? (system* "qemu-img" "create" "-f" "qcow2" "image.qcow2"
(number->string disk-image-size)))
(error "qemu-img failed")))
(mkdir "xchg")
(match references-graphs
((graph-files ...)
;; Copy the reference-graph files under xchg/ so EXP can access it.
(map (lambda (file)
(copy-file file (string-append "xchg/" file)))
graph-files))
(_ #f))
(unless (zero?
(apply system* qemu "-enable-kvm" "-nographic" "-no-reboot"
"-m" (number->string memory-size)
"-net" "nic,model=virtio"
"-virtfs"
(string-append "local,id=store_dev,path="
(%store-directory)
",security_model=none,mount_tag=store")
"-virtfs"
(string-append "local,id=xchg_dev,path=xchg"
",security_model=none,mount_tag=xchg")
"-kernel" linux
"-initrd" initrd
"-append" (string-append "console=ttyS0 --load="
builder)
(if make-disk-image?
'("-hda" "image.qcow2")
'())))
(error "qemu failed" qemu))
(if make-disk-image?
(copy-file "image.qcow2" ; XXX: who mkdir'd OUTPUT?
output)
(begin
(mkdir output)
(copy-recursively "xchg" output))))
(define (read-reference-graph port)
"Return a list of store paths from the reference graph at PORT.
The data at PORT is the format produced by #:references-graphs."
(let loop ((line (read-line port))
(result '()))
(cond ((eof-object? line)
(delete-duplicates result))
((string-prefix? "/" line)
(loop (read-line port)
(cons line result)))
(else
(loop (read-line port)
result)))))
(define* (initialize-partition-table device
#:key
(label-type "msdos")
partition-size)
"Create on DEVICE a partition table of type LABEL-TYPE, with a single
partition of PARTITION-SIZE MiB. Return #t on success."
(display "creating partition table...\n")
(zero? (system* "parted" "/dev/sda" "mklabel" label-type
"mkpart" "primary" "ext2" "1MiB"
(format #f "~aB" partition-size))))
(define* (install-grub grub.cfg device mount-point)
"Install GRUB with GRUB.CFG on DEVICE, which is assumed to be mounted on
MOUNT-POINT. Return #t on success."
(mkdir-p (string-append mount-point "/boot/grub"))
(symlink grub.cfg (string-append mount-point "/boot/grub/grub.cfg"))
(zero? (system* "grub-install" "--no-floppy"
"--boot-directory" (string-append mount-point "/boot")
device)))
(define* (populate-store reference-graphs target)
"Populate the store under directory TARGET with the items specified in
REFERENCE-GRAPHS, a list of reference-graph files."
(define store
(string-append target (%store-directory)))
(define (things-to-copy)
;; Return the list of store files to copy to the image.
(define (graph-from-file file)
(call-with-input-file file read-reference-graph))
(delete-duplicates (append-map graph-from-file reference-graphs)))
(mkdir-p store)
(chmod store #o1775)
(for-each (lambda (thing)
(copy-recursively thing
(string-append target thing)))
(things-to-copy)))
(define (evaluate-populate-directive directive target)
"Evaluate DIRECTIVE, an sexp describing a file or directory to create under
directory TARGET."
(match directive
(('directory name)
(mkdir-p (string-append target name)))
(('directory name uid gid)
(let ((dir (string-append target name)))
(mkdir-p dir)
(chown dir uid gid)))
((new '-> old)
(symlink old (string-append target new)))))
(define (reset-timestamps directory)
"Reset the timestamps of all the files under DIRECTORY, so that they appear
as created and modified at the Epoch."
(display "clearing file timestamps...\n")
(for-each (lambda (file)
(let ((s (lstat file)))
;; XXX: Guile uses libc's 'utime' function (not 'futime'), so
;; the timestamp of symlinks cannot be changed, and there are
;; symlinks here pointing to /gnu/store, which is the host,
;; read-only store.
(unless (eq? (stat:type s) 'symlink)
(utime file 0 0 0 0))))
(find-files directory "")))
(define* (initialize-hard-disk #:key
grub.cfg
disk-image-size
(mkfs "mkfs.ext3")
initialize-store?
(closures-to-copy '())
(directives '()))
(unless (initialize-partition-table "/dev/sda"
#:partition-size
(- disk-image-size (* 5 (expt 2 20))))
(error "failed to create partition table"))
(display "creating ext3 partition...\n")
(unless (zero? (system* mkfs "-F" "/dev/sda1"))
(error "failed to create partition"))
(display "mounting partition...\n")
(mkdir "/fs")
(mount "/dev/sda1" "/fs" "ext3")
(when (pair? closures-to-copy)
;; Populate the store.
(populate-store (map (cut string-append "/xchg/" <>)
closures-to-copy)
"/fs"))
;; Populate /dev.
(make-essential-device-nodes #:root "/fs")
;; Optionally, register the inputs in the image's store.
(when initialize-store?
(for-each (lambda (closure)
(let ((status (system* "guix-register" "--prefix" "/fs"
(string-append "/xchg/" closure))))
(unless (zero? status)
(error "failed to register store items" closure))))
closures-to-copy))
;; Evaluate the POPULATE directives.
(for-each (cut evaluate-populate-directive <> "/fs")
directives)
(unless (install-grub grub.cfg "/dev/sda" "/fs")
(error "failed to install GRUB"))
(reset-timestamps "/fs")
(zero? (system* "umount" "/fs")))
;;; vm.scm ends here
|
