Mirror of GNU Guix
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;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2014, 2015 David Thompson <davet@gnu.org>
;;; Copyright © 2015, 2016 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
;;; 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 grafts)
#:use-module (guix derivations)
#:use-module (guix packages)
#:use-module (guix profiles)
#:use-module (guix search-paths)
#: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 (gnu packages commencement)
#:use-module (gnu packages guile)
#:use-module ((gnu packages bootstrap) #:select (%bootstrap-guile))
#: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-profile-search-paths profile search-paths)
"Evaluate SEARCH-PATHS, a list of search-path specifications, for the
directories in PROFILE, the store path of a profile."
(evaluate-search-paths search-paths (list profile)))
;; Protect some env vars from purification. Borrowed from nix-shell.
(define %precious-variables
(define %default-shell
(or (getenv "SHELL") "/bin/sh"))
(define %network-configuration-files
(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 . _) ...)
(define (create-environment profile paths pure?)
"Set the environment variables specified by PATHS for PROFILE. 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)
(evaluate-profile-search-paths profile paths))
;; Give users a way to know that they're in 'guix environment', so they can
;; adjust 'PS1' accordingly, for instance. Set it to PROFILE so users can
;; conveniently access its contents.
(setenv "GUIX_ENVIRONMENT" profile))
(define (show-search-paths profile search-paths pure?)
"Display SEARCH-PATHS applied to PROFILE. When PURE? is #t, do not augment
existing environment variables with additional search paths."
(for-each (match-lambda
((search-path . value)
(search-path-definition search-path value
#:kind (if pure? 'exact 'prefix)))
(evaluate-profile-search-paths profile search-paths)))
(define (strip-input-name input)
"Remove the name element from the tuple INPUT."
(match input
((_ package) package)
((_ package output)
(list package output))))
(define (package+propagated-inputs package output)
"Return the union of PACKAGE's OUTPUT and its transitive propagated inputs."
(cons (list package output)
(map strip-input-name
(package-transitive-propagated-inputs package))))
(define (package-or-package+output? expr)
"Return #t if EXPR is a package or a 2 element list consisting of a package
and an output string."
(match expr
((or (? package?) ; bare package object
((? package?) (? string?))) ; package+output tuple
(_ #f)))
(define (package-environment-inputs package)
"Return a list of the transitive input packages for PACKAGE."
;; Remove non-package inputs such as origin records.
(filter package-or-package+output?
(map strip-input-name
(package->bag 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"))
(display (_ "
-h, --help display this help and exit"))
(display (_ "
-V, --version display version information and exit"))
(define %default-options
`((system . ,(%current-system))
(substitutes? . #t)
(graft? . #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
(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)
(option '(#\e "expression") #t #f
(lambda (opt name arg result)
(alist-cons 'expression
(tag-package-arg result arg)
(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 (alist-cons 'graft? #f 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)
(option '("expose") #t #f
(lambda (opt name arg result)
(alist-cons 'file-system-mapping
(specification->file-system-mapping arg #f)
(option '("bootstrap") #f #f
(lambda (opt name arg result)
(alist-cons 'bootstrap? #t result)))
(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
(define (package->output package mode)
(match package
((? package?)
(list mode package "out"))
(((? package? package) (? string? output))
(list mode package output))))
(define (packages->outputs packages mode)
(match packages
((? package-or-package+output? package) ; single package
(list (package->output package mode)))
(((? package-or-package+output?) ...) ; many packages
(map (cut package->output <> mode) packages))))
(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.
(packages->outputs (read/eval str) mode))
(('load mode file)
;; Add all the outputs of the package defined in FILE.
(let ((module (make-user-module '())))
(packages->outputs (load* file module) mode)))
(_ '(#f)))
(define* (build-environment derivations opts)
"Build the DERIVATIONS required by the environment using the build options
in OPTS."
(let ((substitutes? (assoc-ref opts 'substitutes?))
(dry-run? (assoc-ref opts 'dry-run?)))
(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))))))
(define (inputs->profile-derivation inputs system bootstrap?)
"Return the derivation for a profile consisting of INPUTS for SYSTEM.
BOOTSTRAP? specifies whether to use the bootstrap Guile to build the
(profile-derivation (packages->manifest inputs)
#:system system
#:hooks (if bootstrap?
(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)
(match input
((drv output)
(list (derivation->output-path drv output)))
(list (derivation->output-path drv)))
((? direct-store-path? path)
(list path)))))
(mlet %store-monad ((reqs (sequence %store-monad
(map input->requisites inputs))))
(return (delete-duplicates (concatenate reqs)))))
(define (status->exit-code status)
"Compute the exit code made from STATUS, a value as returned by 'waitpid',
and suitable for 'exit'."
;; See <bits/waitstatus.h>.
(or (status:exit-val status)
(logior #x80 (status:term-sig status))))
(define exit/status (compose exit status->exit-code))
(define primitive-exit/status (compose primitive-exit status->exit-code))
(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."
;; Properly handle SIGINT, so pressing C-c in an interactive terminal
;; application works.
(sigaction SIGINT SIG_DFL)
(create-environment inputs paths pure?)
(match command
((program . args)
(apply execlp program program args))))
(define (launch-environment/fork command inputs paths pure?)
"Run COMMAND in a new process with an 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."
(match (primitive-fork)
(0 (launch-environment command inputs paths pure?))
(pid (match (waitpid pid)
((_ . status) status)))))
(define* (launch-environment/container #:key command bash user-mappings
profile paths network?)
"Run COMMAND within a container that features the software in PROFILE.
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
(list (direct-store-path bash) profile))))
(let* ((cwd (getcwd))
(passwd (getpwuid (getuid)))
;; Bind-mount all requisite store items, user-specified mappings,
;; /bin/sh, the current working directory, and possibly networking
;; configuration files within the container.
(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)
(source file)
(target file)
;; XXX: On some GNU/Linux
;; systems, /etc/resolv.conf is a
;; symlink to a file in a tmpfs
;; which, for an unknown reason,
;; cannot be bind mounted
;; read-only within the
;; container.
(string=? "/etc/resolv.conf")))))
;; Mappings for the union closure of all inputs.
(map (lambda (dir)
(source dir)
(target dir)
(writable? #f)))
(file-systems (append %container-file-systems
(map mapping->file-system mappings))))
(call-with-container file-systems
(lambda ()
;; Setup global shell.
(mkdir-p "/bin")
(symlink bash "/bin/sh")
;; Set a reasonable default PS1.
(setenv "PS1" "\\u@\\h \\w [env]\\$ ")
;; Setup directory for temporary files.
(mkdir-p "/tmp")
(for-each (lambda (var)
(setenv var "/tmp"))
;; The same variables as in Nix's 'build.cc'.
;; Create a dummy home directory under the same name as on the
;; host.
(mkdir-p (passwd:dir passwd))
(setenv "HOME" (passwd:dir passwd))
;; Create a dummy /etc/passwd to satisfy applications that demand
;; to read it, such as 'git clone' over SSH, a valid use-case when
;; sharing the host's network namespace.
(mkdir-p "/etc")
(call-with-output-file "/etc/passwd"
(lambda (port)
(display (string-join (list (passwd:name passwd)
"x" ; but there is no shadow
"0" "0" ; user is now root
(passwd:gecos passwd)
(passwd:dir passwd)
(newline port)))
;; For convenience, start in the user's current working
;; directory rather than the root directory.
(chdir cwd)
;; A container's environment is already purified, so no need to
;; request it be purified again.
(launch-environment command profile paths #f)))
#:namespaces (if network?
(delq 'net %namespaces) ; share host network
(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
((and container? (not bootstrap?))
(package->derivation bash))
;; Use the bootstrap Bash instead.
((and container? bootstrap?)
(search-bootstrap-binary "bash" system)))
(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) (break (cut string=? "--" <>) args)))
(let ((opts (parse-command-line args %options (list %default-options)
#:argument-handler handle-argument)))
(match command
(() opts)
(("--") opts)
(("--" command ...) (alist-cons 'exec command opts))))))
(define (assert-container-features)
"Check if containers can be created and exit with an informative error
message if any test fails."
(unless (user-namespace-supported?)
(report-error (_ "cannot create container: user namespaces unavailable\n"))
(leave (_ "is your kernel version < 3.10?\n")))
(unless (unprivileged-user-namespace-supported?)
(report-error (_ "cannot create container: unprivileged user cannot create user namespaces\n"))
(leave (_ "please set /proc/sys/kernel/unprivileged_userns_clone to \"1\"\n")))
(unless (setgroups-supported?)
(report-error (_ "cannot create container: /proc/self/setgroups does not exist\n"))
(leave (_ "is your kernel version < 3.19?\n"))))
;; Entry point.
(define (guix-environment . args)
(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 (or (assoc-ref opts 'exec)
;; Spawn a shell if the user didn't specify
;; anything in particular.
(if container?
;; The user's shell is likely not available
;; within the container.
(list %default-shell))))
(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
(('package package _)
(package-environment-inputs package)))
(paths (delete-duplicates
(cons $PATH
(append-map (match-lambda
((or ((? package? p) _ ...)
(? package? p))
(package-native-search-paths p))
(_ '()))
(when container? (assert-container-features))
(with-store store
;; Use the bootstrap Guile when requested.
(parameterize ((%graft? (assoc-ref opts 'graft?))
(if bootstrap?
(canonical-package guile-2.0)))))
(set-build-options-from-command-line store opts)
(run-with-store store
;; Containers need a Bourne shell at /bin/sh.
(mlet* %store-monad ((bash (environment-bash container?
(prof-drv (inputs->profile-derivation
inputs system bootstrap?))
(profile -> (derivation->output-path prof-drv)))
;; First build the inputs. This is necessary even for
;; --search-paths. Additionally, we might need to build bash for
;; a container.
(mbegin %store-monad
(build-environment (if (derivation? bash)
(list prof-drv bash)
(list prof-drv))
((assoc-ref opts 'dry-run?)
(return #t))
((assoc-ref opts 'search-paths)
(show-search-paths profile paths pure?)
(return #t))
(let ((bash-binary
(if bootstrap?
(string-append (derivation->output-path bash)
(launch-environment/container #:command command
#:bash bash-binary
#:user-mappings mappings
#:profile profile
#:paths paths
#:network? network?)))
(launch-environment/fork command profile
paths pure?)))))))))))))