guix/gnu/home-services.scm
Andrew Tropin 5d4f39e64a
home-services: run-on-change: Handle first generation case.
* gnu/home-services.scm
(compute-on-change-gexp): Handle first generation case.

Signed-off-by: Oleg Pykhalov <go.wigust@gmail.com>
2021-09-09 20:26:51 +03:00

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;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2021 Andrew Tropin <andrew@trop.in>
;;; Copyright © 2021 Xinglu Chen <public@yoctocell.xyz>
;;;
;;; 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 (gnu home-services)
#:use-module (gnu services)
#:use-module (guix channels)
#:use-module (guix monads)
#:use-module (guix store)
#:use-module (guix gexp)
#:use-module (guix profiles)
#:use-module (guix sets)
#:use-module (guix ui)
#:use-module (guix discovery)
#:use-module (guix diagnostics)
#:use-module (srfi srfi-1)
#:use-module (ice-9 match)
#:export (home-service-type
home-profile-service-type
home-environment-variables-service-type
home-files-service-type
home-run-on-first-login-service-type
home-activation-service-type
home-run-on-change-service-type
home-provenance-service-type
fold-home-service-types)
#:re-export (service
service-type
service-extension))
;;; Comment:
;;;
;;; This module is similar to (gnu system services) module, but
;;; provides Home Services, which are supposed to be used for building
;;; home-environment.
;;;
;;; Home Services use the same extension as System Services. Consult
;;; (gnu system services) module or manual for more information.
;;;
;;; home-service-type is a root of home services DAG.
;;;
;;; home-profile-service-type is almost the same as profile-service-type, at least
;;; for now.
;;;
;;; home-environment-variables-service-type generates a @file{setup-environment}
;;; shell script, which is expected to be sourced by login shell or other program,
;;; which starts early and spawns all other processes. Home services for shells
;;; automatically add code for sourcing this file, if person do not use those home
;;; services they have to source this script manually in their's shell *profile
;;; file (details described in the manual).
;;;
;;; home-files-service-type is similar to etc-service-type, but doesn't extend
;;; home-activation, because deploy mechanism for config files is pluggable and
;;; can be different for different home environments: The default one is called
;;; symlink-manager (will be introudced in a separate patch series), which creates
;;; links for various dotfiles (like $XDG_CONFIG_HOME/$APP/...) to store, but is
;;; possible to implement alternative approaches like read-only home from Julien's
;;; guix-home-manager.
;;;
;;; home-run-on-first-login-service-type provides an @file{on-first-login} guile
;;; script, which runs provided gexps once, when user makes first login. It can
;;; be used to start user's Shepherd and maybe some other process. It relies on
;;; assumption that /run/user/$UID will be created on login by some login
;;; manager (elogind for example).
;;;
;;; home-activation-service-type provides an @file{activate} guile script, which
;;; do three main things:
;;;
;;; - Sets environment variables to the values declared in
;;; @file{setup-environment} shell script. It's necessary, because user can set
;;; for example XDG_CONFIG_HOME and it should be respected by activation gexp of
;;; symlink-manager.
;;;
;;; - Sets GUIX_NEW_HOME and possibly GUIX_OLD_HOME vars to paths in the store.
;;; Later those variables can be used by activation gexps, for example by
;;; symlink-manager or run-on-change services.
;;;
;;; - Run all activation gexps provided by other home services.
;;;
;;; home-run-on-change-service-type allows to trigger actions during
;;; activation if file or directory specified by pattern is changed.
;;;
;;; Code:
(define (home-derivation entries mextensions)
"Return as a monadic value the derivation of the 'home'
directory containing the given entries."
(mlet %store-monad ((extensions (mapm/accumulate-builds identity
mextensions)))
(lower-object
(file-union "home" (append entries (concatenate extensions))))))
(define home-service-type
;; This is the ultimate service type, the root of the home service
;; DAG. The service of this type is extended by monadic name/item
;; pairs. These items end up in the "home-environment directory" as
;; returned by 'home-environment-derivation'.
(service-type (name 'home)
(extensions '())
(compose identity)
(extend home-derivation)
(default-value '())
(description
"Build the home environment top-level directory,
which in turn refers to everything the home environment needs: its
packages, configuration files, activation script, and so on.")))
(define (packages->profile-entry packages)
"Return a system entry for the profile containing PACKAGES."
;; XXX: 'mlet' is needed here for one reason: to get the proper
;; '%current-target' and '%current-target-system' bindings when
;; 'packages->manifest' is called, and thus when the 'package-inputs'
;; etc. procedures are called on PACKAGES. That way, conditionals in those
;; inputs see the "correct" value of these two parameters. See
;; <https://issues.guix.gnu.org/44952>.
(mlet %store-monad ((_ (current-target-system)))
(return `(("profile" ,(profile
(content (packages->manifest
(map identity
;;(options->transformation transformations)
(delete-duplicates packages eq?))))))))))
;; MAYBE: Add a list of transformations for packages. It's better to
;; place it in home-profile-service-type to affect all profile
;; packages and prevent conflicts, when other packages relies on
;; non-transformed version of package.
(define home-profile-service-type
(service-type (name 'home-profile)
(extensions
(list (service-extension home-service-type
packages->profile-entry)))
(compose concatenate)
(extend append)
(description
"This is the @dfn{home profile} and can be found in
@file{~/.guix-home/profile}. It contains packages and
configuration files that the user has declared in their
@code{home-environment} record.")))
(define (environment-variables->setup-environment-script vars)
"Return a file that can be sourced by a POSIX compliant shell which
initializes the environment. The file will source the home
environment profile, set some default environment variables, and set
environment variables provided in @code{vars}. @code{vars} is a list
of pairs (@code{(key . value)}), @code{key} is a string and
@code{value} is a string or gexp.
If value is @code{#f} variable will be omitted.
If value is @code{#t} variable will be just exported.
For any other, value variable will be set to the @code{value} and
exported."
(define (warn-about-duplicate-defenitions)
(fold
(lambda (x acc)
(when (equal? (car x) (car acc))
(warning
(G_ "duplicate definition for `~a' environment variable ~%") (car x)))
x)
(cons "" "")
(sort vars (lambda (a b)
(string<? (car a) (car b))))))
(warn-about-duplicate-defenitions)
(with-monad
%store-monad
(return
`(("setup-environment"
;; TODO: It's necessary to source ~/.guix-profile too
;; on foreign distros
,(apply mixed-text-file "setup-environment"
"\
HOME_ENVIRONMENT=$HOME/.guix-home
GUIX_PROFILE=\"$HOME_ENVIRONMENT/profile\"
PROFILE_FILE=\"$HOME_ENVIRONMENT/profile/etc/profile\"
[ -f $PROFILE_FILE ] && . $PROFILE_FILE
case $XDG_DATA_DIRS in
*$HOME_ENVIRONMENT/profile/share*) ;;
*) export XDG_DATA_DIRS=$HOME_ENVIRONMENT/profile/share:$XDG_DATA_DIRS ;;
esac
case $MANPATH in
*$HOME_ENVIRONMENT/profile/share/man*) ;;
*) export MANPATH=$HOME_ENVIRONMENT/profile/share/man:$MANPATH
esac
case $INFOPATH in
*$HOME_ENVIRONMENT/profile/share/info*) ;;
*) export INFOPATH=$HOME_ENVIRONMENT/profile/share/info:$INFOPATH ;;
esac
case $XDG_CONFIG_DIRS in
*$HOME_ENVIRONMENT/profile/etc/xdg*) ;;
*) export XDG_CONFIG_DIRS=$HOME_ENVIRONMENT/profile/etc/xdg:$XDG_CONFIG_DIRS ;;
esac
case $XCURSOR_PATH in
*$HOME_ENVIRONMENT/profile/share/icons*) ;;
*) export XCURSOR_PATH=$HOME_ENVIRONMENT/profile/share/icons:$XCURSOR_PATH ;;
esac
"
(append-map
(match-lambda
((key . #f)
'())
((key . #t)
(list "export " key "\n"))
((key . value)
(list "export " key "=" value "\n")))
vars)))))))
(define home-environment-variables-service-type
(service-type (name 'home-environment-variables)
(extensions
(list (service-extension
home-service-type
environment-variables->setup-environment-script)))
(compose concatenate)
(extend append)
(default-value '())
(description "Set the environment variables.")))
(define (files->files-directory files)
"Return a @code{files} directory that contains FILES."
(define (assert-no-duplicates files)
(let loop ((files files)
(seen (set)))
(match files
(() #t)
(((file _) rest ...)
(when (set-contains? seen file)
(raise (formatted-message (G_ "duplicate '~a' entry for files/")
file)))
(loop rest (set-insert file seen))))))
;; Detect duplicates early instead of letting them through, eventually
;; leading to a build failure of "files.drv".
(assert-no-duplicates files)
(file-union "files" files))
(define (files-entry files)
"Return an entry for the @file{~/.guix-home/files}
directory containing FILES."
(with-monad %store-monad
(return `(("files" ,(files->files-directory files))))))
(define home-files-service-type
(service-type (name 'home-files)
(extensions
(list (service-extension home-service-type
files-entry)))
(compose concatenate)
(extend append)
(default-value '())
(description "Configuration files for programs that
will be put in @file{~/.guix-home/files}.")))
(define (compute-on-first-login-script _ gexps)
(gexp->script
"on-first-login"
#~(let* ((xdg-runtime-dir (or (getenv "XDG_RUNTIME_DIR")
(format #f "/run/user/~a" (getuid))))
(flag-file-path (string-append
xdg-runtime-dir "/on-first-login-executed"))
(touch (lambda (file-name)
(call-with-output-file file-name (const #t)))))
;; XDG_RUNTIME_DIR dissapears on logout, that means such trick
;; allows to launch on-first-login script on first login only
;; after complete logout/reboot.
(when (not (file-exists? flag-file-path))
(begin #$@gexps (touch flag-file-path))))))
(define (on-first-login-script-entry m-on-first-login)
"Return, as a monadic value, an entry for the on-first-login script
in the home environment directory."
(mlet %store-monad ((on-first-login m-on-first-login))
(return `(("on-first-login" ,on-first-login)))))
(define home-run-on-first-login-service-type
(service-type (name 'home-run-on-first-login)
(extensions
(list (service-extension
home-service-type
on-first-login-script-entry)))
(compose identity)
(extend compute-on-first-login-script)
(default-value #f)
(description "Run gexps on first user login. Can be
extended with one gexp.")))
(define (compute-activation-script init-gexp gexps)
(gexp->script
"activate"
#~(let* ((he-init-file (lambda (he) (string-append he "/setup-environment")))
(he-path (string-append (getenv "HOME") "/.guix-home"))
(new-home-env (getenv "GUIX_NEW_HOME"))
(new-home (or new-home-env
;; Path of the activation file if called interactively
(dirname (car (command-line)))))
(old-home-env (getenv "GUIX_OLD_HOME"))
(old-home (or old-home-env
(if (file-exists? (he-init-file he-path))
(readlink he-path)
#f))))
(if (file-exists? (he-init-file new-home))
(let* ((port ((@ (ice-9 popen) open-input-pipe)
(format #f "source ~a && env -0"
(he-init-file new-home))))
(result ((@ (ice-9 rdelim) read-delimited) "" port))
(vars (map (lambda (x)
(let ((si (string-index x #\=)))
(cons (string-take x si)
(string-drop x (1+ si)))))
((@ (srfi srfi-1) remove)
string-null?
(string-split result #\nul)))))
(close-port port)
(map (lambda (x) (setenv (car x) (cdr x))) vars)
(setenv "GUIX_NEW_HOME" new-home)
(setenv "GUIX_OLD_HOME" old-home)
#$@gexps
;; Do not unset env variable if it was set outside.
(unless new-home-env (setenv "GUIX_NEW_HOME" #f))
(unless old-home-env (setenv "GUIX_OLD_HOME" #f)))
(format #t "\
Activation script was either called or loaded by file from this direcotry:
~a
It doesn't seem that home environment is somewhere around.
Make sure that you call ./activate by symlink from -home store item.\n"
new-home)))))
(define (activation-script-entry m-activation)
"Return, as a monadic value, an entry for the activation script
in the home environment directory."
(mlet %store-monad ((activation m-activation))
(return `(("activate" ,activation)))))
(define home-activation-service-type
(service-type (name 'home-activation)
(extensions
(list (service-extension
home-service-type
activation-script-entry)))
(compose identity)
(extend compute-activation-script)
(default-value #f)
(description "Run gexps to activate the current
generation of home environment and update the state of the home
directory. @command{activate} script automatically called during
reconfiguration or generation switching. This service can be extended
with one gexp, but many times, and all gexps must be idempotent.")))
;;;
;;; On-change.
;;;
(define (compute-on-change-gexp eval-gexps? pattern-gexp-tuples)
#~(begin
(define (equal-regulars? file1 file2)
"Check if FILE1 and FILE2 are bit for bit identical."
(let* ((cmp-binary #$(file-append
(@ (gnu packages base) diffutils) "/bin/cmp"))
(stats1 (lstat file1))
(stats2 (lstat file2)))
(cond
((= (stat:ino stats1) (stat:ino stats2)) #t)
((not (= (stat:size stats1) (stat:size stats2))) #f)
(else (= (system* cmp-binary file1 file2) 0)))))
(define (equal-symlinks? symlink1 symlink2)
"Check if SYMLINK1 and SYMLINK2 are pointing to the same target."
(string=? (readlink symlink1) (readlink symlink2)))
(define (equal-directories? dir1 dir2)
"Check if DIR1 and DIR2 have the same content."
(define (ordinary-file file)
(not (or (string=? file ".")
(string=? file ".."))))
(let* ((files1 (scandir dir1 ordinary-file))
(files2 (scandir dir2 ordinary-file)))
(if (equal? files1 files2)
(map (lambda (file)
(equal-files?
(string-append dir1 "/" file)
(string-append dir2 "/" file)))
files1)
#f)))
(define (equal-files? file1 file2)
"Compares files, symlinks or directories of the same type."
(case (file-type file1)
((directory) (equal-directories? file1 file2))
((symlink) (equal-symlinks? file1 file2))
((regular) (equal-regulars? file1 file2))
(else
(display "The file type is unsupported by on-change service.\n")
#f)))
(define (file-type file)
(stat:type (lstat file)))
(define (something-changed? file1 file2)
(cond
((and (not (file-exists? file1))
(not (file-exists? file2))) #f)
((or (not (file-exists? file1))
(not (file-exists? file2))) #t)
((not (eq? (file-type file1) (file-type file2))) #t)
(else
(not (equal-files? file1 file2)))))
(define expressions-to-eval
(map
(lambda (x)
(let* ((file1 (string-append
(or (getenv "GUIX_OLD_HOME")
"/gnu/store/non-existing-generation")
"/" (car x)))
(file2 (string-append (getenv "GUIX_NEW_HOME") "/" (car x)))
(_ (format #t "Comparing ~a and\n~10t~a..." file1 file2))
(any-changes? (something-changed? file1 file2))
(_ (format #t " done (~a)\n"
(if any-changes? "changed" "same"))))
(if any-changes? (cadr x) "")))
'#$pattern-gexp-tuples))
(if #$eval-gexps?
(begin
(display "Evaling on-change gexps.\n\n")
(for-each primitive-eval expressions-to-eval)
(display "On-change gexps evaluation finished.\n\n"))
(display "\
On-change gexps won't be evaluated, disabled by service
configuration.\n"))))
(define home-run-on-change-service-type
(service-type (name 'home-run-on-change)
(extensions
(list (service-extension
home-activation-service-type
identity)))
(compose concatenate)
(extend compute-on-change-gexp)
(default-value #t)
(description "\
G-expressions to run if the specified files have changed since the
last generation. The extension should be a list of lists where the
first element is the pattern for file or directory that expected to be
changed, and the second element is the G-expression to be evaluated.")))
;;;
;;; Provenance tracking.
;;;
(define home-provenance-service-type
(service-type
(name 'home-provenance)
(extensions
(list (service-extension
home-service-type
(service-extension-compute
(first (service-type-extensions provenance-service-type))))))
(default-value #f) ;the HE config file
(description "\
Store provenance information about the home environment in the home
environment itself: the channels used when building the home
environment, and its configuration file, when available.")))
(define sexp->home-provenance sexp->system-provenance)
(define home-provenance system-provenance)
;;;
;;; Searching
;;;
(define (parent-directory directory)
"Get the parent directory of DIRECTORY"
(string-join (drop-right (string-split directory #\/) 1) "/"))
(define %guix-home-root-directory
;; Absolute file name of the module hierarchy.
(parent-directory (dirname (search-path %load-path "gnu/home-services.scm"))))
(define %service-type-path
;; Search path for service types.
(make-parameter `((,%guix-home-root-directory . "gnu/home-services"))))
(define (all-home-service-modules)
"Return the default set of home-service modules."
(cons (resolve-interface '(gnu home-services))
(all-modules (%service-type-path)
#:warn warn-about-load-error)))
(define* (fold-home-service-types proc seed)
(fold-service-types proc seed (all-home-service-modules)))