scripts: Add 'environment' command.

* guix/scripts/environment.scm: New file.
* Makefile.am (MODULES): Add it.
* doc/guix.texi ("Invoking guix environment"): New node.
This commit is contained in:
David Thompson 2014-09-21 13:40:05 -04:00
parent e25234e34b
commit 372c4bbcbb
3 changed files with 318 additions and 0 deletions

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@ -94,6 +94,7 @@ MODULES = \
guix/scripts/system.scm \
guix/scripts/lint.scm \
guix/scripts/import/nix.scm \
guix/scripts/environment.scm \
guix.scm \
$(GNU_SYSTEM_MODULES)

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@ -33,6 +33,12 @@ Documentation License''.
Managing the operating system configuration.
@end direntry
@dircategory Software development
@direntry
* guix environment: (guix)Invoking guix environment
Building development environments with Guix.
@end direntry
@titlepage
@title GNU Guix Reference Manual
@subtitle Using the GNU Guix Functional Package Manager
@ -2431,6 +2437,7 @@ programming interface of Guix in a convenient way.
* Invoking guix hash:: Computing the cryptographic hash of a file.
* Invoking guix refresh:: Updating package definitions.
* Invoking guix lint:: Finding errors in package definitions.
* Invoking guix environment:: Setting up development environments.
@end menu
@node Invoking guix build
@ -2840,6 +2847,81 @@ and exit.
@end table
@node Invoking guix environment
@section Invoking @command{guix environment}
The purpose of @command{guix environment} is to assist hackers in
creating reproducible development environments without polluting their
package profile. The @command{guix environment} tool takes one or more
packages, builds all of the necessary inputs, and creates a shell
environment to use them.
The general syntax is:
@example
guix environment @var{options} @var{package}@dots{}
@end example
The following examples spawns a new shell that is capable of building
the GNU Guile source code:
@example
guix environment guile
@end example
If the specified packages are not built yet, @command{guix environment}
automatically builds them. The new shell's environment is an augmented
version of the environment that @command{guix environment} was run in.
It contains the necessary search paths for building the given package
added to the existing environment variables. To create a ``pure''
environment in which the original environment variables have been unset,
use the @code{--pure} option.
Additionally, more than one package may be specified, in which case the
union of the inputs for the given packages are used. For example, the
command below spawns a shell where all of the dependencies of both Guile
and Emacs are available:
@example
guix environment guile emacs
@end example
Sometimes an interactive shell session is not desired. The
@code{--exec} option can be used to specify the command to run instead.
@example
guix environment guile --exec=make
@end example
The following options are available:
@table @code
@item --expression=@var{expr}
@itemx -e @var{expr}
Create an environment for the package that @var{expr} evaluates to.
@item --load=@var{file}
@itemx -l @var{file}
Create an environment for the package that the code within @var{file}
evaluates to.
@item --exec=@var{command}
@item -E @var{command}
Execute @var{command} in the new environment.
@item --pure
Unset existing environment variables when building the new environment.
This has the effect of creating an environment in which search paths
only contain package inputs.
@item --search-paths
Display the environment variable definitions that make up the
environment.
@end table
It also supports all of the common build options that @command{guix
build} supports (@pxref{Invoking guix build, common build options}).
@c *********************************************************************
@node GNU Distribution
@chapter GNU Distribution

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@ -0,0 +1,235 @@
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2014 David Thompson <davet@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 scripts environment)
#:use-module (guix ui)
#:use-module (guix store)
#:use-module (guix derivations)
#:use-module (guix packages)
#:use-module (guix profiles)
#:use-module (guix utils)
#:use-module (guix monads)
#:use-module (guix build utils)
#:use-module (guix scripts build)
#:use-module (gnu packages)
#:use-module (ice-9 format)
#:use-module (ice-9 match)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-26)
#:use-module (srfi srfi-37)
#:use-module (srfi srfi-98)
#:export (guix-environment))
(define (for-each-search-path proc inputs derivations pure?)
"Apply PROC for each native search path in INPUTS in addition to 'PATH'.
Use the output paths of DERIVATIONS to build each search path. When PURE? is
#t, the existing search path value is ignored. Otherwise, the existing search
path value is appended."
(let ((paths (map derivation->output-path derivations)))
(for-each (match-lambda
(($ <search-path-specification>
variable directories separator)
(let* ((current (getenv variable))
(path ((@@ (guix build utils) search-path-as-list)
directories paths))
(value (list->search-path-as-string path separator)))
(proc variable
(if (and current (not pure?))
(string-append value separator current)
value)))))
(cons* (search-path-specification
(variable "PATH")
(directories '("bin" "sbin"))
(separator ":"))
(delete-duplicates
(append-map package-native-search-paths inputs))))))
;; Protect some env vars from purification. Borrowed from nix-shell.
(define %precious-variables
'("HOME" "USER" "LOGNAME" "DISPLAY" "TERM" "TZ" "PAGER"))
(define (purify-environment)
"Unset almost all environment variables. A small number of variables such
as 'HOME' and 'USER' are left untouched."
(for-each unsetenv
(remove (cut member <> %precious-variables)
(match (get-environment-variables)
(((names . _) ...)
names)))))
(define (create-environment inputs derivations pure?)
"Set the needed environment variables for all packages within INPUTS. When
PURE? is #t, unset the variables in the current environment. Otherwise,
augment existing enviroment variables with additional search paths."
(when pure? (purify-environment))
(for-each-search-path setenv inputs derivations pure?))
(define (show-search-paths inputs derivations pure?)
"Display the needed search paths to build an environment that contains the
packages within INPUTS. When PURE? is #t, do not augment existing environment
variables with additional search paths."
(for-each-search-path (lambda (variable value)
(format #t "export ~a=\"~a\"~%" variable value))
inputs derivations pure?))
(define (show-help)
(display (_ "Usage: guix environment [OPTION]... PACKAGE...
Build an environment that includes the dependencies of PACKAGE and execute a
shell command in that environment.\n"))
(display (_ "
-e, --expression=EXPR create environment for the package that EXPR
evaluates to"))
(display (_ "
-l, --load=FILE create environment for the package that the code within
FILE evaluates to"))
(display (_ "
-E, --exec=COMMAND execute COMMAND in new environment"))
(display (_ "
--pure unset existing environment variables"))
(display (_ "
--search-paths display needed environment variable definitions"))
(newline)
(show-build-options-help)
(newline)
(display (_ "
-h, --help display this help and exit"))
(display (_ "
-V, --version display version information and exit"))
(show-bug-report-information))
(define %default-options
;; Default to opening a new shell.
`((exec . ,(or (getenv "SHELL") "/bin/sh"))
(substitutes? . #t)
(max-silent-time . 3600)
(verbosity . 0)))
(define %options
;; Specification of the command-line options.
(cons* (option '(#\h "help") #f #f
(lambda args
(show-help)
(exit 0)))
(option '(#\V "version") #f #f
(lambda args
(show-version-and-exit "guix environment")))
(option '("pure") #f #f
(lambda (opt name arg result)
(alist-cons 'pure #t result)))
(option '(#\E "exec") #t #f
(lambda (opt name arg result)
(alist-cons 'exec arg result)))
(option '("search-paths") #f #f
(lambda (opt name arg result)
(alist-cons 'search-paths #t result)))
(option '(#\l "load") #t #f
(lambda (opt name arg result)
(alist-cons 'load arg result)))
(option '(#\e "expression") #t #f
(lambda (opt name arg result)
(alist-cons 'expression arg result)))
(option '(#\n "dry-run") #f #f
(lambda (opt name arg result)
(alist-cons 'dry-run? #t result)))
%standard-build-options))
(define (pick-all alist key)
"Return a list of values in ALIST associated with KEY."
(define same-key? (cut eq? key <>))
(fold (lambda (pair memo)
(match pair
(((? same-key? k) . v)
(cons v memo))
(_ memo)))
'() alist))
(define (options/resolve-packages opts)
"Return OPTS with package specification strings replaced by actual
packages."
(map (match-lambda
(('package . (? string? spec))
`(package . ,(specification->package spec)))
(('expression . str)
(match (read/eval str)
((? package? p)
`(package . ,p))))
(('load . file)
`(package . ,(load (string-append (getcwd) "/" file))))
(opt opt))
opts))
(define (packages->transitive-inputs packages)
"Return a list of the transitive inputs for all PACKAGES."
(define (transitive-inputs package)
(filter-map (match-lambda
((_ (? package? package)) package)
(_ #f))
(bag-transitive-inputs
(package->bag package))))
(delete-duplicates
(append-map transitive-inputs packages)))
;; TODO: Deduplicate these.
(define show-what-to-build*
(store-lift show-what-to-build))
(define set-build-options-from-command-line*
(store-lift set-build-options-from-command-line))
(define (build-inputs inputs opts)
"Build the packages in INPUTS using the build options in OPTS."
(let ((substitutes? (assoc-ref opts 'substitutes?))
(dry-run? (assoc-ref opts 'dry-run?)))
(mlet* %store-monad ((drvs (sequence %store-monad
(map package->derivation inputs))))
(mbegin %store-monad
(show-what-to-build* drvs
#:use-substitutes? substitutes?
#:dry-run? dry-run?)
(if dry-run?
(return #f)
(mbegin %store-monad
(set-build-options-from-command-line* opts)
(built-derivations drvs)
(return drvs)))))))
;; Entry point.
(define (guix-environment . args)
(define (parse-options)
(args-fold* args %options
(lambda (opt name arg result)
(leave (_ "~A: unrecognized option~%") name))
(lambda (arg result)
(alist-cons 'package arg result))
%default-options))
(with-store store
(let* ((opts (parse-options))
(pure? (assoc-ref opts 'pure))
(command (assoc-ref opts 'exec))
(inputs (packages->transitive-inputs
(pick-all (options/resolve-packages opts) 'package)))
(drvs (run-with-store store (build-inputs inputs opts))))
(cond ((assoc-ref opts 'dry-run?)
#t)
((assoc-ref opts 'search-paths)
(show-search-paths inputs drvs pure?))
(else
(create-environment inputs drvs pure?)
(system command))))))