pack: Add '--localstatedir' option.

* guix/scripts/pack.scm (self-contained-tarball): Add #:localstatedir?
parameter and honor it.
(%options, show-help): Add '--localstatedir'.
(guix-pack): Honor it.
* gnu/build/install.scm (populate-single-profile-directory): Add
 #:register? parameter and honor it.
* doc/guix.texi (Binary Installation): Use '--localstatedir' in
example.
(Invoking guix pack): Document it.

4 files changed, 57 insertions, 22 deletions

diff --git a/Makefile.am b/Makefile.am
index 2684d66bf1..23171ae837 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -488,7 +488,7 @@ AM_DISTCHECK_CONFIGURE_FLAGS =			\
 guix-binary.%.tar.xz:
 	$(AM_V_GEN)GUIX_PACKAGE_PATH=				\
 	tarball=`$(top_builddir)/pre-inst-env guix pack -C xz	\
-	  -s "$*" guix` ;					\
+	  -s "$*" --localstatedir guix` ;			\
 	cp "$$tarball" "$@.tmp" ; mv "$@.tmp" "$@"
 
 
diff --git a/doc/guix.texi b/doc/guix.texi
index f4cc207e7b..86fc86da61 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -535,7 +535,7 @@ make guix-binary.@var{system}.tar.xz
 ... which, in turn, runs:
 
 @example
-guix pack -s @var{system} guix
+guix pack -s @var{system} --localstatedir guix
 @end example
 
 @xref{Invoking guix pack}, for more info on this handy tool.
@@ -2434,6 +2434,19 @@ the system type of the build host.
 @itemx -C @var{tool}
 Compress the resulting tarball using @var{tool}---one of @code{gzip},
 @code{bzip2}, @code{xz}, or @code{lzip}.
+
+@item --localstatedir
+Include the ``local state directory'', @file{/var/guix}, in the
+resulting pack.
+
+@file{/var/guix} contains the store database (@pxref{The Store}) as well
+as garbage-collector roots (@pxref{Invoking guix gc}).  Providing it in
+the pack means that the store is ``complete'' and manageable by Guix;
+not providing it pack means that the store is ``dead'': items cannot be
+added to it or removed from it after extraction of the pack.
+
+One use case for this is the Guix self-contained binary tarball
+(@pxref{Binary Installation}).
 @end table
 
 In addition, @command{guix pack} supports all the common build options
diff --git a/gnu/build/install.scm b/gnu/build/install.scm
index 5c2b35632d..11f107d63c 100644
--- a/gnu/build/install.scm
+++ b/gnu/build/install.scm
@@ -1,5 +1,5 @@
 ;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2013, 2014, 2015, 2016 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2013, 2014, 2015, 2016, 2017 Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright © 2016 Chris Marusich <cmmarusich@gmail.com>
 ;;;
 ;;; This file is part of GNU Guix.
@@ -192,13 +192,16 @@ rest of STORE."
 
 (define* (populate-single-profile-directory directory
                                             #:key profile closure
-                                            deduplicate?)
+                                            deduplicate?
+                                            register?)
   "Populate DIRECTORY with a store containing PROFILE, whose closure is given
 in the file called CLOSURE (as generated by #:references-graphs.)  DIRECTORY
 is initialized to contain a single profile under /root pointing to PROFILE.
-DEDUPLICATE? determines whether to deduplicate files in the store.
+When REGISTER? is true, initialize DIRECTORY/var/guix/db to reflect the
+contents of the store; DEDUPLICATE? determines whether to deduplicate files in
+the store.
 
-This is used to create the self-contained Guix tarball."
+This is used to create the self-contained tarballs with 'guix pack'."
   (define (scope file)
     (string-append directory "/" file))
 
@@ -213,14 +216,16 @@ This is used to create the self-contained Guix tarball."
 
   ;; Populate the store.
   (populate-store (list closure) directory)
-  (register-closure (canonicalize-path directory) closure
-                    #:deduplicate? deduplicate?)
-
-  ;; XXX: 'guix-register' registers profiles as GC roots but the symlink
-  ;; target uses $TMPDIR.  Fix that.
-  (delete-file (scope "/var/guix/gcroots/profiles"))
-  (symlink* "/var/guix/profiles"
-            "/var/guix/gcroots/profiles")
+
+  (when register?
+    (register-closure (canonicalize-path directory) closure
+                      #:deduplicate? deduplicate?)
+
+    ;; XXX: 'guix-register' registers profiles as GC roots but the symlink
+    ;; target uses $TMPDIR.  Fix that.
+    (delete-file (scope "/var/guix/gcroots/profiles"))
+    (symlink* "/var/guix/profiles"
+              "/var/guix/gcroots/profiles"))
 
   ;; Make root's profile, which makes it a GC root.
   (mkdir-p* %root-profile)
diff --git a/guix/scripts/pack.scm b/guix/scripts/pack.scm
index e8f3d800a8..138e2c5b77 100644
--- a/guix/scripts/pack.scm
+++ b/guix/scripts/pack.scm
@@ -69,10 +69,12 @@ found."
 
 (define* (self-contained-tarball name profile
                                  #:key deduplicate?
-                                 (compressor (first %compressors)))
+                                 (compressor (first %compressors))
+                                 localstatedir?)
   "Return a self-contained tarball containing a store initialized with the
-closure of PROFILE, a derivation.  The tarball contains /gnu/store, /var/guix,
-and PROFILE is available as /root/.guix-profile."
+closure of PROFILE, a derivation.  The tarball contains /gnu/store; if
+LOCALSTATEDIR? is true, it also contains /var/guix, including /var/guix/db
+with a properly initialized store database."
   (define build
     (with-imported-modules '((guix build utils)
                              (guix build store-copy)
@@ -85,7 +87,10 @@ and PROFILE is available as /root/.guix-profile."
 
           ;; We need Guix here for 'guix-register'.
           (setenv "PATH"
-                  (string-append #$guix "/sbin:" #$tar "/bin:"
+                  (string-append #$(if localstatedir?
+                                       (file-append guix "/sbin:")
+                                       "")
+                                 #$tar "/bin:"
                                  #$(compressor-package compressor) "/bin"))
 
           ;; Note: there is not much to gain here with deduplication and
@@ -94,7 +99,8 @@ and PROFILE is available as /root/.guix-profile."
           (populate-single-profile-directory %root
                                              #:profile #$profile
                                              #:closure "profile"
-                                             #:deduplicate? #f)
+                                             #:deduplicate? #f
+                                             #:register? #$localstatedir?)
 
           ;; Create the tarball.  Use GNU format so there's no file name
           ;; length limitation.
@@ -119,7 +125,10 @@ and PROFILE is available as /root/.guix-profile."
                             ;; extracting the archive.  Do not include /root
                             ;; because the root account might have a
                             ;; different home directory.
-                            "./var/guix"
+                            #$@(if localstatedir?
+                                   '("./var/guix")
+                                   '())
+
                             (string-append "." (%store-directory))))))))
 
   (gexp->derivation (string-append name ".tar."
@@ -163,6 +172,9 @@ and PROFILE is available as /root/.guix-profile."
                  (lambda (opt name arg result)
                    (alist-cons 'compressor (lookup-compressor arg)
                                result)))
+         (option '("localstatedir") #f #f
+                 (lambda (opt name arg result)
+                   (alist-cons 'localstatedir? #t result)))
 
          (append %transformation-options
                  %standard-build-options)))
@@ -178,6 +190,8 @@ Create a bundle of PACKAGE.\n"))
   -s, --system=SYSTEM    attempt to build for SYSTEM--e.g., \"i686-linux\""))
   (display (_ "
   -C, --compression=TOOL compress using TOOL--e.g., \"lzip\""))
+  (display (_ "
+      --localstatedir    include /var/guix in the resulting pack"))
   (newline)
   (display (_ "
   -h, --help             display this help and exit"))
@@ -209,14 +223,17 @@ Create a bundle of PACKAGE.\n"))
                                     (specification->package+output spec))
                                 list))
                             specs))
-             (compressor (assoc-ref opts 'compressor)))
+             (compressor (assoc-ref opts 'compressor))
+             (localstatedir? (assoc-ref opts 'localstatedir?)))
         (with-store store
           (run-with-store store
             (mlet* %store-monad ((profile (profile-derivation
                                            (packages->manifest packages)))
                                  (drv (self-contained-tarball "pack" profile
                                                               #:compressor
-                                                              compressor)))
+                                                              compressor
+                                                              #:localstatedir?
+                                                              localstatedir?)))
               (mbegin %store-monad
                 (show-what-to-build* (list drv)
                                      #:use-substitutes?