guix-devel/guix/scripts/environment.scm

509 lines
22 KiB
Scheme

;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2014, 2015 David Thompson <davet@gnu.org>
;;; Copyright © 2015 Ludovic Courtès <ludo@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 search-paths)
#:use-module (guix utils)
#:use-module (guix build utils)
#:use-module (guix monads)
#:use-module ((guix gexp) #:select (lower-inputs))
#:use-module (guix scripts)
#:use-module (guix scripts build)
#:use-module (gnu build linux-container)
#:use-module (gnu system linux-container)
#:use-module (gnu system file-systems)
#:use-module (gnu packages)
#:use-module (gnu packages bash)
#:use-module (ice-9 format)
#:use-module (ice-9 match)
#:use-module (ice-9 rdelim)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-11)
#:use-module (srfi srfi-26)
#:use-module (srfi srfi-37)
#:use-module (srfi srfi-98)
#:export (guix-environment))
(define (evaluate-input-search-paths inputs search-paths)
"Evaluate SEARCH-PATHS, a list of search-path specifications, for the
directories corresponding to INPUTS, a list of (DERIVATION) or (DERIVATION
OUTPUT) tuples."
(let ((directories (map (match-lambda
(((? derivation? drv))
(derivation->output-path drv))
(((? derivation? drv) output)
(derivation->output-path drv output))
(((? string? item))
item))
inputs)))
(evaluate-search-paths search-paths directories)))
;; Protect some env vars from purification. Borrowed from nix-shell.
(define %precious-variables
'("HOME" "USER" "LOGNAME" "DISPLAY" "TERM" "TZ" "PAGER"))
(define %default-shell
(or (getenv "SHELL") "/bin/sh"))
(define %network-configuration-files
'("/etc/resolv.conf"
"/etc/nsswitch.conf"
"/etc/services"
"/etc/hosts"))
(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 paths pure?)
"Set the environment variables specified by PATHS for all the 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 (match-lambda
((($ <search-path-specification> variable _ separator) . value)
(let ((current (getenv variable)))
(setenv variable
(if (and current (not pure?))
(string-append value separator current)
value)))))
(evaluate-input-search-paths inputs paths))
;; Give users a way to know that they're in 'guix environment', so they can
;; adjust 'PS1' accordingly, for instance.
(setenv "GUIX_ENVIRONMENT" "t"))
(define (show-search-paths inputs search-paths pure?)
"Display SEARCH-PATHS applied to the packages specified by INPUTS, a list of
(DERIVATION) or (DERIVATION OUTPUT) tuples. When PURE? is #t, do not augment
existing environment variables with additional search paths."
(for-each (match-lambda
((search-path . value)
(display
(search-path-definition search-path value
#:kind (if pure? 'exact 'prefix)))
(newline)))
(evaluate-input-search-paths inputs search-paths)))
(define (package+propagated-inputs package output)
"Return the union of PACKAGE's OUTPUT and its transitive propagated inputs."
`((,(package-name package) ,package ,output)
,@(package-transitive-propagated-inputs package)))
(define (show-help)
(display (_ "Usage: guix environment [OPTION]... PACKAGE... [-- COMMAND...]
Build an environment that includes the dependencies of PACKAGE and execute
COMMAND or an interactive shell 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 (_ "
--ad-hoc include all specified packages in the environment instead
of only their inputs"))
(display (_ "
--pure unset existing environment variables"))
(display (_ "
--search-paths display needed environment variable definitions"))
(display (_ "
-s, --system=SYSTEM attempt to build for SYSTEM--e.g., \"i686-linux\""))
(display (_ "
-C, --container run command within an isolated container"))
(display (_ "
-N, --network allow containers to access the network"))
(display (_ "
--share=SPEC for containers, share writable host file system
according to SPEC"))
(display (_ "
--expose=SPEC for containers, expose read-only host file system
according to SPEC"))
(display (_ "
--bootstrap use bootstrap binaries to build the environment"))
(newline)
(show-build-options-help)
(newline)
(display (_ "
-h, --help display this help and exit"))
(display (_ "
-V, --version display version information and exit"))
(newline)
(show-bug-report-information))
(define %default-options
;; Default to opening a new shell.
`((exec . (,%default-shell))
(system . ,(%current-system))
(substitutes? . #t)
(max-silent-time . 3600)
(verbosity . 0)))
(define (tag-package-arg opts arg)
"Return a two-element list with the form (TAG ARG) that tags ARG with either
'ad-hoc' in OPTS has the 'ad-hoc?' key set to #t, or 'inputs' otherwise."
;; Normally, the transitive inputs to a package are added to an environment,
;; but the ad-hoc? flag changes the meaning of a package argument such that
;; the package itself is added to the environment instead.
(if (assoc-ref opts 'ad-hoc?)
`(ad-hoc-package ,arg)
`(package ,arg)))
(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 ; deprecated
(lambda (opt name arg result)
(alist-cons 'exec (list %default-shell "-c" 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
(tag-package-arg result arg)
result)))
(option '(#\e "expression") #t #f
(lambda (opt name arg result)
(alist-cons 'expression
(tag-package-arg result arg)
result)))
(option '("ad-hoc") #f #f
(lambda (opt name arg result)
(alist-cons 'ad-hoc? #t result)))
(option '(#\n "dry-run") #f #f
(lambda (opt name arg result)
(alist-cons 'dry-run? #t result)))
(option '(#\s "system") #t #f
(lambda (opt name arg result)
(alist-cons 'system arg
(alist-delete 'system result eq?))))
(option '(#\C "container") #f #f
(lambda (opt name arg result)
(alist-cons 'container? #t result)))
(option '(#\N "network") #f #f
(lambda (opt name arg result)
(alist-cons 'network? #t result)))
(option '("share") #t #f
(lambda (opt name arg result)
(alist-cons 'file-system-mapping
(specification->file-system-mapping arg #t)
result)))
(option '("expose") #t #f
(lambda (opt name arg result)
(alist-cons 'file-system-mapping
(specification->file-system-mapping arg #f)
result)))
(option '("bootstrap") #f #f
(lambda (opt name arg result)
(alist-cons 'bootstrap? #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 (compact lst)
"Remove all #f elements from LST."
(filter identity lst))
(define (options/resolve-packages opts)
"Return OPTS with package specification strings replaced by actual
packages."
(compact
(append-map (match-lambda
(('package mode (? string? spec))
(let-values (((package output)
(specification->package+output spec)))
(list (list mode package output))))
(('expression mode str)
;; Add all the outputs of the package STR evaluates to.
(match (read/eval str)
((? package? package)
(map (lambda (output)
(list mode package output))
(package-outputs package)))))
(('load mode file)
;; Add all the outputs of the package defined in FILE.
(let ((package (load* file (make-user-module '()))))
(map (lambda (output)
(list mode package output))
(package-outputs package))))
(_ '(#f)))
opts)))
(define (build-inputs inputs opts)
"Build the derivations in INPUTS, a list of (DERIVATION) or (DERIVATION
OUTPUT) tuples, using the build options in OPTS."
(let ((substitutes? (assoc-ref opts 'substitutes?))
(dry-run? (assoc-ref opts 'dry-run?)))
(match inputs
(((derivations _ ...) ...)
(mbegin %store-monad
(show-what-to-build* derivations
#:use-substitutes? substitutes?
#:dry-run? dry-run?)
(if dry-run?
(return #f)
(mbegin %store-monad
(set-build-options-from-command-line* opts)
(built-derivations derivations)
(return derivations))))))))
(define requisites* (store-lift requisites))
(define (inputs->requisites inputs)
"Convert INPUTS, a list of input tuples or store path strings, into a set of
requisite store items i.e. the union closure of all the inputs."
(define (input->requisites input)
(requisites*
(match input
((drv output)
(derivation->output-path drv output))
((drv)
(derivation->output-path drv))
((? direct-store-path? path)
path))))
(mlet %store-monad ((reqs (sequence %store-monad
(map input->requisites inputs))))
(return (delete-duplicates (concatenate reqs)))))
(define exit/status (compose exit status:exit-val))
(define primitive-exit/status (compose primitive-exit status:exit-val))
(define (launch-environment command inputs paths pure?)
"Run COMMAND in a new environment containing INPUTS, using the native search
paths defined by the list PATHS. When PURE?, pre-existing environment
variables are cleared before setting the new ones."
(create-environment inputs paths pure?)
(apply system* command))
(define* (launch-environment/container #:key command bash user-mappings
inputs paths network?)
"Run COMMAND within a Linux container. The environment features INPUTS, a
list of derivations to be shared from the host system. Environment variables
are set according to PATHS, a list of native search paths. The global shell
is BASH, a file name for a GNU Bash binary in the store. When NETWORK?,
access to the host system network is permitted. USER-MAPPINGS, a list of file
system mappings, contains the user-specified host file systems to mount inside
the container."
(mlet %store-monad ((reqs (inputs->requisites
(cons (direct-store-path bash) inputs))))
(return
(let* ((cwd (getcwd))
;; Bind-mount all requisite store items, user-specified mappings,
;; /bin/sh, the current working directory, and possibly networking
;; configuration files within the container.
(mappings
(append user-mappings
;; Current working directory.
(list (file-system-mapping
(source cwd)
(target cwd)
(writable? #t)))
;; When in Rome, do as Nix build.cc does: Automagically
;; map common network configuration files.
(if network?
(filter-map (lambda (file)
(and (file-exists? file)
(file-system-mapping
(source file)
(target file)
(writable? #f))))
%network-configuration-files)
'())
;; Mappings for the union closure of all inputs.
(map (lambda (dir)
(file-system-mapping
(source dir)
(target dir)
(writable? #f)))
reqs)))
(file-systems (append %container-file-systems
(map mapping->file-system mappings))))
(exit/status
(call-with-container (map file-system->spec file-systems)
(lambda ()
;; Setup global shell.
(mkdir-p "/bin")
(symlink bash "/bin/sh")
;; Setup directory for temporary files.
(mkdir-p "/tmp")
(for-each (lambda (var)
(setenv var "/tmp"))
;; The same variables as in Nix's 'build.cc'.
'("TMPDIR" "TEMPDIR" "TMP" "TEMP"))
;; From Nix build.cc:
;;
;; Set HOME to a non-existing path to prevent certain
;; programs from using /etc/passwd (or NIS, or whatever)
;; to locate the home directory (for example, wget looks
;; for ~/.wgetrc). I.e., these tools use /etc/passwd if
;; HOME is not set, but they will just assume that the
;; settings file they are looking for does not exist if
;; HOME is set but points to some non-existing path.
(setenv "HOME" "/homeless-shelter")
;; For convenience, start in the user's current working
;; directory rather than the root directory.
(chdir cwd)
(primitive-exit/status
;; A container's environment is already purified, so no need to
;; request it be purified again.
(launch-environment command inputs paths #f)))
#:namespaces (if network?
(delq 'net %namespaces) ; share host network
%namespaces)))))))
(define (environment-bash container? bootstrap? system)
"Return a monadic value in the store monad for the version of GNU Bash
needed in the environment for SYSTEM, if any. If CONTAINER? is #f, return #f.
If CONTAINER? and BOOTSTRAP?, return the store path for the bootstrap Bash.
Otherwise, return the derivation for the Bash package."
(with-monad %store-monad
(cond
((and container? (not bootstrap?))
(package->derivation bash))
;; Use the bootstrap Bash instead.
((and container? bootstrap?)
(interned-file
(search-bootstrap-binary "bash" system)))
(else
(return #f)))))
(define (parse-args args)
"Parse the list of command line arguments ARGS."
(define (handle-argument arg result)
(alist-cons 'package (tag-package-arg result arg) result))
;; The '--' token is used to separate the command to run from the rest of
;; the operands.
(let-values (((args command) (split args "--")))
(let ((opts (parse-command-line args %options (list %default-options)
#:argument-handler handle-argument)))
(if (null? command)
opts
(alist-cons 'exec command opts)))))
;; Entry point.
(define (guix-environment . args)
(with-error-handling
(let* ((opts (parse-args args))
(pure? (assoc-ref opts 'pure))
(container? (assoc-ref opts 'container?))
(network? (assoc-ref opts 'network?))
(bootstrap? (assoc-ref opts 'bootstrap?))
(system (assoc-ref opts 'system))
(command (assoc-ref opts 'exec))
(packages (options/resolve-packages opts))
(mappings (pick-all opts 'file-system-mapping))
(inputs (delete-duplicates
(append-map (match-lambda
(('ad-hoc-package package output)
(package+propagated-inputs package
output))
(('package package output)
(bag-transitive-inputs
(package->bag package))))
packages)))
(paths (delete-duplicates
(cons $PATH
(append-map (match-lambda
((label (? package? p) _ ...)
(package-native-search-paths p))
(_
'()))
inputs))
eq?)))
(with-store store
(run-with-store store
(mlet* %store-monad ((inputs (lower-inputs
(map (match-lambda
((label item)
(list item))
((label item output)
(list item output)))
inputs)
#:system system))
;; Containers need a Bourne shell at /bin/sh.
(bash (environment-bash container?
bootstrap?
system)))
(mbegin %store-monad
;; First build the inputs. This is necessary even for
;; --search-paths. Additionally, we might need to build bash
;; for a container.
(build-inputs (if (derivation? bash)
`((,bash "out") ,@inputs)
inputs)
opts)
(cond
((assoc-ref opts 'dry-run?)
(return #t))
((assoc-ref opts 'search-paths)
(show-search-paths inputs paths pure?)
(return #t))
(container?
(let ((bash-binary
(if bootstrap?
bash
(string-append (derivation->output-path bash)
"/bin/sh"))))
(launch-environment/container #:command command
#:bash bash-binary
#:user-mappings mappings
#:inputs inputs
#:paths paths
#:network? network?)))
(else
(return
(exit/status
(launch-environment command inputs paths pure?))))))))))))