; base system for creating installer images

(use-modules (freya system)
	     (gnu packages disk)
	     (gnu packages linux)
	     (gnu packages cryptsetup)
	     (gnu packages file-systems)
	     (gnu services shepherd)
	     (guix modules)
	     (gnu))

; copy over installer disk utilites

(define %installer-disk-utilities
  (list parted gptfdisk ddrescue
        lvm2-static
        cryptsetup mdadm
        dosfstools
        btrfs-progs
        e2fsprogs
        f2fs-tools
        jfsutils
        xfsprogs))

; copy over cow store

(define %backing-directory
  ;; Sub-directory used as the backing store for copy-on-write.
  "/tmp/guix-inst")

(define cow-store-service-type
  (shepherd-service-type
   'cow-store
   (lambda _
     (define (import-module? module)
       ;; Since we don't use deduplication support in 'populate-store', don't
       ;; import (guix store deduplication) and its dependencies, which
       ;; includes Guile-Gcrypt.
       (and (guix-module-name? module)
            (not (equal? module '(guix store deduplication)))))

     (shepherd-service
      (requirement '(root-file-system user-processes))
      (provision '(cow-store))
      (documentation
       "Make the store copy-on-write, with writes going to \
the given target.")

      ;; This is meant to be explicitly started by the user.
      (auto-start? #f)

      (modules `((gnu build install)
                 ,@%default-modules))
      (start
       (with-imported-modules (source-module-closure
                               '((gnu build install))
                               #:select? import-module?)
         #~(case-lambda
             ((target)
              (mount-cow-store target #$%backing-directory)
              target)
             (else
              ;; Do nothing, and mark the service as stopped.
              #f))))
      (stop #~(lambda (target)
                ;; Delete the temporary directory, but leave everything
                ;; mounted as there may still be processes using it since
                ;; 'user-processes' doesn't depend on us.  The 'user-file-systems'
                ;; service will unmount TARGET eventually.
                (delete-file-recursively
                 (string-append target #$%backing-directory))))))
   (description "Make the store copy-on-write, with writes going to \
the given target.")))

(define (cow-store-service)
  "Return a service that makes the store copy-on-write, such that writes go to
the user's target storage device rather than on the RAM disk."
  ;; See <http://bugs.gnu.org/18061> for the initial report.
  (service cow-store-service-type 'mooooh!))

; installer system

(operating-system
  (inherit base-operating-system)
  (host-name "installer")

  (file-systems
	(append %base-live-file-systems
		%base-file-systems))

  (users (list (user-account
		 (name "root")
		 (group "root")
		 (supplementary-groups '("wheel")) ; allow use of sudo
		 (password "")
		 (comment "root"))))

  (pam-services
    ;; Explicitly allow for empty passwords.
    (base-pam-services #:allow-empty-passwords? #t))

  (packages (append %installer-disk-utilities
		    %freya-base-packages))

  (services (append %freya-base-services
		    (list (cow-store-service))))

  (bootloader (bootloader-configuration
		(bootloader grub-bootloader)
		(targets '("/dev/sda")))))