guix-devel/guix/scripts/environment.scm

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;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2014, 2015, 2018 David Thompson <davet@gnu.org>
;;; Copyright © 2015, 2016, 2017, 2018, 2019 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2018 Mike Gerwitz <mtg@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 status) #:select (with-status-verbosity))
#: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 build accounts)
#: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))
;; 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 (purify-environment white-list)
"Unset all environment variables except those that match the regexps in
WHITE-LIST and those listed in %PRECIOUS-VARIABLES. A small number of
variables such as 'HOME' and 'USER' are left untouched."
(for-each unsetenv
(remove (lambda (variable)
(or (member variable %precious-variables)
(find (cut regexp-exec <> variable)
white-list)))
(match (get-environment-variables)
(((names . _) ...)
names)))))
(define* (create-environment profile manifest
#:key pure? (white-list '()))
"Set the environment variables specified by MANIFEST for PROFILE. When
PURE? is #t, unset the variables in the current environment except those that
match the regexps in WHITE-LIST. Otherwise, augment existing environment
variables with additional search paths."
(when pure?
(purify-environment white-list))
(for-each (match-lambda
((($ <search-path-specification> variable _ separator) . value)
(let ((current (getenv variable)))
(setenv variable
(if (and current (not pure?))
(if separator
(string-append value separator current)
value)
value)))))
(profile-search-paths profile manifest))
;; 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 manifest #:key pure?)
"Display the search paths of MANIFEST applied to PROFILE. 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)))
(profile-search-paths profile manifest)))
(define (input->manifest-entry input)
"Return a manifest entry for INPUT, or #f if INPUT does not correspond to a
package."
(match input
((_ (? package? package))
(package->manifest-entry package))
((_ (? package? package) output)
(package->manifest-entry package output))
(_
#f)))
(define (package-environment-inputs package)
"Return a list of manifest entries corresponding to the transitive input
packages for PACKAGE."
;; Remove non-package inputs such as origin records.
(filter-map input->manifest-entry
(bag-transitive-inputs (package->bag package))))
(define (show-help)
(display (G_ "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 (G_ "
-e, --expression=EXPR create environment for the package that EXPR
evaluates to"))
(display (G_ "
-l, --load=FILE create environment for the package that the code within
FILE evaluates to"))
(display (G_ "
-m, --manifest=FILE create environment with the manifest from FILE"))
(display (G_ "
--ad-hoc include all specified packages in the environment instead
of only their inputs"))
(display (G_ "
--pure unset existing environment variables"))
(display (G_ "
-E, --preserve=REGEXP preserve environment variables that match REGEXP"))
(display (G_ "
--search-paths display needed environment variable definitions"))
(display (G_ "
-s, --system=SYSTEM attempt to build for SYSTEM--e.g., \"i686-linux\""))
(display (G_ "
-r, --root=FILE make FILE a symlink to the result, and register it
as a garbage collector root"))
(display (G_ "
-C, --container run command within an isolated container"))
(display (G_ "
-N, --network allow containers to access the network"))
(display (G_ "
-P, --link-profile link environment profile to ~/.guix-profile within
an isolated container"))
(display (G_ "
-u, --user=USER instead of copying the name and home of the current
user into an isolated container, use the name USER
with home directory /home/USER"))
(display (G_ "
--share=SPEC for containers, share writable host file system
according to SPEC"))
(display (G_ "
--expose=SPEC for containers, expose read-only host file system
according to SPEC"))
(display (G_ "
-v, --verbosity=LEVEL use the given verbosity LEVEL"))
(display (G_ "
--bootstrap use bootstrap binaries to build the environment"))
(newline)
(show-build-options-help)
(newline)
(show-transformation-options-help)
(newline)
(display (G_ "
-h, --help display this help and exit"))
(display (G_ "
-V, --version display version information and exit"))
(newline)
(show-bug-report-information))
(define %default-options
`((system . ,(%current-system))
(substitutes? . #t)
(build-hook? . #t)
(graft? . #t)
(print-build-trace? . #t)
(print-extended-build-trace? . #t)
(multiplexed-build-output? . #t)
(debug . 0)
(verbosity . 2)))
(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 "preserve") #t #f
(lambda (opt name arg result)
(alist-cons 'inherit-regexp
(make-regexp* arg)
result)))
(option '("inherit") #t #f ;deprecated
(lambda (opt name arg result)
(warning (G_ "'--inherit' is deprecated, \
use '--preserve' instead~%"))
(alist-cons 'inherit-regexp
(make-regexp* 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 '(#\m "manifest") #t #f
(lambda (opt name arg result)
(alist-cons 'manifest
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 (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 '(#\P "link-profile") #f #f
(lambda (opt name arg result)
(alist-cons 'link-profile? #t result)))
(option '(#\u "user") #t #f
(lambda (opt name arg result)
(alist-cons 'user arg
(alist-delete 'user result eq?))))
(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 '(#\r "root") #t #f
(lambda (opt name arg result)
(alist-cons 'gc-root arg result)))
(option '(#\v "verbosity") #t #f
(lambda (opt name arg result)
(let ((level (string->number* arg)))
(alist-cons 'verbosity level
(alist-delete 'verbosity result)))))
(option '("bootstrap") #f #f
(lambda (opt name arg result)
(alist-cons 'bootstrap? #t result)))
(append %transformation-options
%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 store opts)
"Return OPTS with package specification strings replaced by manifest entries
for the corresponding packages."
(define (manifest-entry=? e1 e2)
(and (eq? (manifest-entry-item e1) (manifest-entry-item e2))
(string=? (manifest-entry-output e1)
(manifest-entry-output e2))))
(define transform
(cut (options->transformation opts) store <>))
(define* (package->manifest-entry* package #:optional (output "out"))
(package->manifest-entry (transform package) output))
(define (packages->outputs packages mode)
(match packages
((? package? package)
(if (eq? mode 'ad-hoc-package)
(list (package->manifest-entry* package))
(package-environment-inputs package)))
(((? package? package) (? string? output))
(if (eq? mode 'ad-hoc-package)
(list (package->manifest-entry* package output))
(package-environment-inputs package)))
((lst ...)
(append-map (cut packages->outputs <> mode) lst))))
(manifest
(delete-duplicates
(append-map (match-lambda
(('package 'ad-hoc-package (? string? spec))
(let-values (((package output)
(specification->package+output spec)))
(list (package->manifest-entry* package output))))
(('package 'package (? string? spec))
(package-environment-inputs
(specification->package+output spec)))
(('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)))
(('manifest . file)
(let ((module (make-user-module '((guix profiles) (gnu)))))
(manifest-entries (load* file module))))
(_ '()))
opts)
manifest-entry=?)))
(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)
(built-derivations derivations)))))
(define (manifest->derivation manifest system bootstrap?)
"Return the derivation for a profile of MANIFEST.
BOOTSTRAP? specifies whether to use the bootstrap Guile to build the profile."
(profile-derivation manifest
#:system system
;; Packages can have conflicting inputs, or explicit
;; inputs that conflict with implicit inputs (e.g., gcc,
;; gzip, etc.). Thus, do not error out when we
;; encounter collision.
#:allow-collisions? #t
#:hooks (if bootstrap?
'()
%default-profile-hooks)
#:locales? (not 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)
(requisites*
(match input
((drv output)
(list (derivation->output-path drv output)))
((drv)
(list (derivation->output-path drv)))
((? direct-store-path? path)
(list path)))))
(mlet %store-monad ((reqs (mapm %store-monad
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 profile manifest
#:key pure? (white-list '()))
"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, except those matching the
regexps in WHITE-LIST."
;; Properly handle SIGINT, so pressing C-c in an interactive terminal
;; application works.
(sigaction SIGINT SIG_DFL)
(create-environment profile manifest
#:pure? pure? #:white-list white-list)
(match command
((program . args)
(apply execlp program program args))))
(define* (launch-environment/fork command profile manifest
#:key pure? (white-list '()))
"Run COMMAND in a new process with an environment containing PROFILE, with
the search paths specified by MANIFEST. When PURE?, pre-existing environment
variables are cleared before setting the new ones, except those matching the
regexps in WHITE-LIST."
(match (primitive-fork)
(0 (launch-environment command profile manifest
#:pure? pure?
#:white-list white-list))
(pid (match (waitpid pid)
((_ . status) status)))))
(define* (launch-environment/container #:key command bash user user-mappings
profile manifest link-profile? network?)
"Run COMMAND within a container that features the software in PROFILE.
Environment variables are set according to the search paths of MANIFEST.
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. If USER is not #f, each
target of USER-MAPPINGS will be re-written relative to '/home/USER', and USER
will be used for the passwd entry. LINK-PROFILE? creates a symbolic link from
~/.guix-profile to the environment profile."
(mlet %store-monad ((reqs (inputs->requisites
(list (direct-store-path bash) profile))))
(return
(let* ((cwd (getcwd))
(home (getenv "HOME"))
(uid (if user 1000 (getuid)))
(gid (if user 1000 (getgid)))
(passwd (let ((pwd (getpwuid (getuid))))
(password-entry
(name (or user (passwd:name pwd)))
(real-name (if user
""
(passwd:gecos pwd)))
(uid uid) (gid gid) (shell bash)
(directory (if user
(string-append "/home/" user)
(passwd:dir pwd))))))
(groups (list (group-entry (name "users") (gid gid))
(group-entry (gid 65534) ;the overflow GID
(name "overflow"))))
(home-dir (password-entry-directory passwd))
;; Bind-mount all requisite store items, user-specified mappings,
;; /bin/sh, the current working directory, and possibly networking
;; configuration files within the container.
(mappings
(override-user-mappings
user home
(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?
%network-file-mappings
'())
;; 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 file-system-mapping->bind-mount
mappings))))
(exit/status
(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'.
'("TMPDIR" "TEMPDIR" "TMP" "TEMP"))
;; Create a dummy home directory.
(mkdir-p home-dir)
(setenv "HOME" home-dir)
;; If requested, link $GUIX_ENVIRONMENT to $HOME/.guix-profile;
;; this allows programs expecting that path to continue working as
;; expected within a container.
(when link-profile? (link-environment profile home-dir))
;; 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")
(write-passwd (list passwd))
(write-group groups)
;; For convenience, start in the user's current working
;; directory rather than the root directory.
(chdir (override-user-dir user home cwd))
(primitive-exit/status
;; A container's environment is already purified, so no need to
;; request it be purified again.
(launch-environment command profile manifest #:pure? #f)))
#:guest-uid uid
#:guest-gid gid
#:namespaces (if network?
(delq 'net %namespaces) ; share host network
%namespaces)))))))
(define (user-override-home user)
"Return home directory for override user USER."
(string-append "/home/" user))
(define (override-user-mappings user home mappings)
"If a username USER is provided, rewrite each HOME prefix in file system
mappings MAPPINGS to a home directory determined by 'override-user-dir';
otherwise, return MAPPINGS."
(if (not user)
mappings
(map (lambda (mapping)
(let ((target (file-system-mapping-target mapping)))
(if (string-prefix? home target)
(file-system-mapping
(source (file-system-mapping-source mapping))
(target (override-user-dir user home target))
(writable? (file-system-mapping-writable? mapping)))
mapping)))
mappings)))
(define (override-user-dir user home dir)
"If username USER is provided, overwrite string prefix HOME in DIR with a
directory determined by 'user-override-home'; otherwise, return DIR."
(if (and user (string-prefix? home dir))
(string-append (user-override-home user)
(substring dir (string-length home)))
dir))
(define (link-environment profile home-dir)
"Create a symbolic link from HOME-DIR/.guix-profile to PROFILE."
(let ((profile-dir (string-append home-dir "/.guix-profile")))
(catch 'system-error
(lambda ()
(symlink profile profile-dir))
(lambda args
(if (= EEXIST (system-error-errno args))
(leave (G_ "cannot link profile: '~a' already exists within container~%")
profile-dir)
(apply throw args))))))
(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) (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 (G_ "cannot create container: user namespaces unavailable\n"))
(leave (G_ "is your kernel version < 3.10?\n")))
(unless (unprivileged-user-namespace-supported?)
(report-error (G_ "cannot create container: unprivileged user cannot create user namespaces\n"))
(leave (G_ "please set /proc/sys/kernel/unprivileged_userns_clone to \"1\"\n")))
(unless (setgroups-supported?)
(report-error (G_ "cannot create container: /proc/self/setgroups does not exist\n"))
(leave (G_ "is your kernel version < 3.19?\n"))))
(define (register-gc-root target root)
"Make ROOT an indirect root to TARGET. This is procedure is idempotent."
(let* ((root (if (string-prefix? "/" root)
root
(string-append (canonicalize-path (dirname root))
"/" root))))
(catch 'system-error
(lambda ()
(symlink target root)
((store-lift add-indirect-root) root))
(lambda args
(if (and (= EEXIST (system-error-errno args))
(equal? (false-if-exception (readlink root)) target))
(with-monad %store-monad
(return #t))
(apply throw args))))))
;;;
;;; Entry point.
;;;
(define (guix-environment . args)
(with-error-handling
(let* ((opts (parse-args args))
(pure? (assoc-ref opts 'pure))
(container? (assoc-ref opts 'container?))
(link-prof? (assoc-ref opts 'link-profile?))
(network? (assoc-ref opts 'network?))
(user (assoc-ref opts 'user))
(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.
'("/bin/sh")
(list %default-shell))))
(mappings (pick-all opts 'file-system-mapping))
(white-list (pick-all opts 'inherit-regexp)))
(when container? (assert-container-features))
(when (and (not container?) link-prof?)
(leave (G_ "'--link-profile' cannot be used without '--container'~%")))
(when (and (not container?) user)
(leave (G_ "'--user' cannot be used without '--container'~%")))
(with-store store
(with-status-verbosity (assoc-ref opts 'verbosity)
(define manifest
(options/resolve-packages store opts))
(set-build-options-from-command-line store opts)
;; Use the bootstrap Guile when requested.
(parameterize ((%graft? (assoc-ref opts 'graft?))
(%guile-for-build
(package-derivation
store
(if bootstrap?
%bootstrap-guile
(canonical-package guile-2.2)))))
(run-with-store store
;; Containers need a Bourne shell at /bin/sh.
(mlet* %store-monad ((bash (environment-bash container?
bootstrap?
system))
(prof-drv (manifest->derivation
manifest system bootstrap?))
(profile -> (derivation->output-path prof-drv))
(gc-root -> (assoc-ref opts 'gc-root)))
;; 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))
opts)
(mwhen gc-root
(register-gc-root profile gc-root))
(cond
((assoc-ref opts 'dry-run?)
(return #t))
((assoc-ref opts 'search-paths)
(show-search-paths profile manifest #:pure? 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 user
#:user-mappings mappings
#:profile profile
#:manifest manifest
#:link-profile? link-prof?
#:network? network?)))
(else
(return
(exit/status
(launch-environment/fork command profile manifest
#:white-list white-list
#:pure? pure?))))))))))))))