Subject: Re: [bug#30572] [PATCH 6/7] system: Add "guix system docker-image" command.

From: [email-masked] (Ludovic Courtès)
Date: Tue, 27 Feb 2018 18:17:12 +0100

Chris Marusich <[email-masked]> skribis:

> +  (mlet %store-monad ((os-drv (operating-system-derivation os #:container? #t))

Since <operating-system> has a gexp compiler, this line is no longer
needed.  Instead you can write:

  #~(do something with #$os)

> +                      (name -> (string-append name ".tar.gz"))
> +                      (system-graph-name -> "system")
> +                      ;; Use a Guile that supports dlopen because it needs to
> +                      ;; dlopen libgcrypt in the initrd.  See:
> +                      ;; https://lists.gnu.org/archive/html/guix-devel/2017-10/msg00233.html
> +                      (initrd (base-initrd %linux-vm-file-systems
> +                                           #:virtio? #t
> +                                           #:guile guile-2.2)))

Uh, that must be a big initrd indeed.  :-)

> +    (define build
> +      (with-imported-modules `(,@(source-module-closure '((guix docker)
> +                                                          (gnu build vm)
> +                                                          (guix build utils)
> +                                                          (guix build syscalls))
> +                                                        #:select? not-config?)
> +                               ((guix config) => ,config))
> +        #~(begin
> +            ;; Guile-JSON is required by (guix docker).
> +            (add-to-load-path
> +             (string-append #+json "/share/guile/site/"
> +                            (effective-version)))
> +            (use-modules (gnu build vm)
> +                         (guix build utils)
> +                         (guix build syscalls)
> +                         (srfi srfi-26)
> +                         (ice-9 match)
> +                         (guix docker)
> +                         (srfi srfi-19))
> +
> +            (let* ((inputs
> +                    '#$(append (list tree parted e2fsprogs dosfstools tar)
> +                               (map canonical-package
> +                                    (list sed grep coreutils findutils gawk))
> +                               (if register-closures? (list guix) '())))
> +
> +                   ;; This variable is unused but allows us to add INPUTS-TO-COPY
> +                   ;; as inputs.
> +                   (to-register '#$os-drv)
> +                   (initialize (root-partition-initializer
> +                                #:closures '(#$system-graph-name)
> +                                #:register-closures? #$register-closures?
> +                                #:system-directory #$os-drv
> +                                ;; De-duplication would fail due to
> +                                ;; cross-device link errors, so don't do it.
> +                                #:deduplicate? #f))
> +                   (root "/tmp/root"))
> +
> +              (set-path-environment-variable "PATH" '("bin" "sbin") inputs)
> +              (mkdir-p root)
> +              (initialize root)
> +              ;; Use a temporary directory inside xchg to avoid hitting space
> +              ;; limitations in the initrd's root file system.
> +              (let ((tmpdir "/xchg/tmp/docker-image"))
> +                (build-docker-image
> +                 (string-append "/xchg/" #$name) ;; The output file.
> +                 #$os-drv
> +                 #:closure (string-append "/xchg/" #$system-graph-name)
> +                 #:compressor '(#+(file-append gzip "/bin/gzip") "-9n")
> +                 #:creation-time (make-time time-utc 0 1)
> +                 #:tmpdir tmpdir
> +                 #:extra-items-dir root))))))
> +    (expression->derivation-in-linux-vm
> +     name
> +     build

What about here replacing ‘build’ on the line above with something like:

  #~(execl #$(program-file "build-docker-image.scm" build)
          "build-docker-image")

This would create a ‘build-docker-image.scm’ script that uses the real
Guile 2.2, but we could still use guile-static-stripped in the initrd.

WDYT?

Thanks!

Ludo’.