linux-initrd: Return file-like objects instead of monadic values.

This is an incompatible change visible to users via the 'initrd' field of 'operating-system'. However, assuming the user's 'initrd' value tail-calls to 'raw-initrd' or 'base-initrd', the switch to non-monadic style is invisible. * gnu/system/linux-initrd.scm (expression->initrd): Use 'computed-file' instead of 'gexp->derivation'. (raw-initrd, base-initrd): Adjust docstring to mention non-monadic return. * gnu/system/vm.scm (expression->derivation-in-linux-vm): Adjust accordingly. * gnu/system.scm (operating-system-directory-base-entries) (operating-system-initrd-file) (operating-system-boot-parameters): Adjust accordingly. * doc/guix.texi (operating-system Reference) (Initial RAM Disk): Update.
2018-11-15 18:39:18 +01:00 · 2018-11-15 18:39:18 +01:00 · e34ae75dc1
parent a7ef45d9de
commit e34ae75dc1
4 changed files with 28 additions and 31 deletions
--- a/doc/guix.texi
+++ b/doc/guix.texi
@ -9860,7 +9860,7 @@ The list of Linux kernel modules that need to be available in the
 initial RAM disk.  @xref{Initial RAM Disk}.

@item @code{initrd} (default: @code{base-initrd})
-A monadic procedure that returns an initial RAM disk for the Linux
+A procedure that returns an initial RAM disk for the Linux
 kernel.  This field is provided to support low-level customization and
 should rarely be needed for casual use.  @xref{Initial RAM Disk}.

@ -21917,10 +21917,10 @@ here is how to use it and customize it further.

@cindex initrd
@cindex initial RAM disk
-@deffn {Monadic Procedure} raw-initrd @var{file-systems} @
+@deffn {Scheme Procedure} raw-initrd @var{file-systems} @
       [#:linux-modules '()] [#:mapped-devices '()] @
       [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
-Return a monadic derivation that builds a raw initrd.  @var{file-systems} is
+Return a derivation that builds a raw initrd.  @var{file-systems} is
 a list of file systems to be mounted by the initrd, possibly in addition to
 the root file system specified on the kernel command line via @code{--root}.
@var{linux-modules} is a list of kernel modules to be loaded at boot time.
@ -21938,10 +21938,10 @@ When @var{volatile-root?} is true, the root file system is writable but any chan
 to it are lost.
@end deffn

-@deffn {Monadic Procedure} base-initrd @var{file-systems} @
+@deffn {Scheme Procedure} base-initrd @var{file-systems} @
       [#:mapped-devices '()] [#:qemu-networking? #f] [#:volatile-root? #f]@
       [#:linux-modules '()]
-Return a monadic derivation that builds a generic initrd, with kernel
+Return as a file-like object a generic initrd, with kernel
 modules taken from @var{linux}.  @var{file-systems} is a list of file-systems to be
 mounted by the initrd, possibly in addition to the root file system specified
 on the kernel command line via @code{--root}.  @var{mapped-devices} is a list of device
@ -21961,9 +21961,9 @@ program.  That gives a lot of flexibility.  The
@code{expression->initrd} procedure builds such an initrd, given the
 program to run in that initrd.

-@deffn {Monadic Procedure} expression->initrd @var{exp} @
+@deffn {Scheme Procedure} expression->initrd @var{exp} @
       [#:guile %guile-static-stripped] [#:name "guile-initrd"]
-Return a derivation that builds a Linux initrd (a gzipped cpio archive)
+Return as a file-like object a Linux initrd (a gzipped cpio archive)
 containing @var{guile} and that evaluates @var{exp}, a G-expression,
 upon booting.  All the derivations referenced by @var{exp} are
 automatically copied to the initrd.
--- a/gnu/system.scm
+++ b/gnu/system.scm
@ -154,7 +154,7 @@
                    (default '()))                ; list of gexps/strings
  (bootloader operating-system-bootloader)        ; <bootloader-configuration>

-  (initrd operating-system-initrd                 ; (list fs) -> M derivation
+  (initrd operating-system-initrd                 ; (list fs) -> file-like
          (default base-initrd))
  (initrd-modules operating-system-initrd-modules ; list of strings
                  (thunked)                       ; it's system-dependent
@ -442,7 +442,7 @@ value of the SYSTEM-SERVICE-TYPE service."
          (return `(("locale" ,locale)))
          (mlet %store-monad
              ((kernel  ->  (operating-system-kernel os))
-               (initrd      (operating-system-initrd-file os))
+               (initrd  ->  (operating-system-initrd-file os))
               (params      (operating-system-boot-parameters-file os)))
            (return `(("kernel" ,kernel)
                      ("parameters" ,params)
@ -870,12 +870,12 @@ hardware-related operations as necessary when booting a Linux container."
  (define make-initrd
    (operating-system-initrd os))

-  (mlet %store-monad ((initrd (make-initrd boot-file-systems
-                                           #:linux (operating-system-kernel os)
-                                           #:linux-modules
-                                           (operating-system-initrd-modules os)
-                                           #:mapped-devices mapped-devices)))
-    (return (file-append initrd "/initrd"))))
+  (let ((initrd (make-initrd boot-file-systems
+                             #:linux (operating-system-kernel os)
+                             #:linux-modules
+                             (operating-system-initrd-modules os)
+                             #:mapped-devices mapped-devices)))
+    (file-append initrd "/initrd")))

 (define (locale-name->definition* name)
  "Variant of 'locale-name->definition' that raises an error upon failure."
@ -957,7 +957,7 @@ listed in OS.  The C library expects to find it under
 parameters of OS.  When SYSTEM-KERNEL-ARGUMENTS? is true, add kernel arguments
 such as '--root' and '--load' to <boot-parameters>."
  (mlet* %store-monad
-      ((initrd (operating-system-initrd-file os))
+      ((initrd -> (operating-system-initrd-file os))
       (store -> (operating-system-store-file-system os))
       (bootloader  -> (bootloader-configuration-bootloader
                        (operating-system-bootloader os)))
--- a/gnu/system/linux-initrd.scm
+++ b/gnu/system/linux-initrd.scm
@ -20,8 +20,6 @@
 ;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.

 (define-module (gnu system linux-initrd)
-  #:use-module (guix monads)
-  #:use-module (guix store)
  #:use-module (guix gexp)
  #:use-module (guix utils)
  #:use-module ((guix store)
@ -63,7 +61,7 @@
                             (gzip gzip)
                             (name "guile-initrd")
                             (system (%current-system)))
-  "Return a derivation that builds a Linux initrd (a gzipped cpio archive)
+  "Return as a file-like object a Linux initrd (a gzipped cpio archive)
 containing GUILE and that evaluates EXP, a G-expression, upon booting.  All
 the derivations referenced by EXP are automatically copied to the initrd."

@ -100,8 +98,9 @@ the derivations referenced by EXP are automatically copied to the initrd."
                        #:references-graphs '("closure")
                        #:gzip (string-append #$gzip "/bin/gzip")))))

-  (gexp->derivation name builder
-                    #:references-graphs `(("closure" ,init))))
+  (computed-file name builder
+                 #:options
+                 `(#:references-graphs (("closure" ,init)))))

 (define (flat-linux-module-directory linux modules)
  "Return a flat directory containing the Linux kernel modules listed in
@ -143,7 +142,7 @@ MODULES and taken from LINUX."
                      qemu-networking?
                      volatile-root?
                      (on-error 'debug))
-  "Return a monadic derivation that builds a raw initrd, with kernel
+  "Return as a file-like object a raw initrd, with kernel
 modules taken from LINUX.  FILE-SYSTEMS is a list of file-systems to be
 mounted by the initrd, possibly in addition to the root file system specified
 on the kernel command line via '--root'. LINUX-MODULES is a list of kernel
@ -294,7 +293,7 @@ FILE-SYSTEMS."
                      volatile-root?
                      (extra-modules '())         ;deprecated
                      (on-error 'debug))
-  "Return a monadic derivation that builds a generic initrd, with kernel
+  "Return as a file-like object a generic initrd, with kernel
 modules taken from LINUX.  FILE-SYSTEMS is a list of file-systems to be
 mounted by the initrd, possibly in addition to the root file system specified
 on the kernel command line via '--root'.  MAPPED-DEVICES is a list of device
--- a/gnu/system/vm.scm
+++ b/gnu/system/vm.scm
@ -189,14 +189,12 @@ made available under the /xchg CIFS share."
                  #~(when (zero? (system* #$user-builder))
                      (reboot))))

-  (mlet* %store-monad
-      ((initrd       (if initrd                   ; use the default initrd?
-                         (return initrd)
-                         (base-initrd file-systems
-                                      #:on-error 'backtrace
-                                      #:linux linux
-                                      #:linux-modules %base-initrd-modules
-                                      #:qemu-networking? #t))))
+  (let ((initrd (or initrd
+                    (base-initrd file-systems
+                                 #:on-error 'backtrace
+                                 #:linux linux
+                                 #:linux-modules %base-initrd-modules
+                                 #:qemu-networking? #t))))

    (define builder
      ;; Code that launches the VM that evaluates EXP.