diff --git a/doc/guix.texi b/doc/guix.texi index bd659d7036..d149732c19 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -97,6 +97,7 @@ Copyright @copyright{} 2021 Hui Lu@* Copyright @copyright{} 2021 pukkamustard@* Copyright @copyright{} 2021 Alice Brenon@* Copyright @copyright{} 2021, 2022 Josselin Poiret@* +Copyright @copyright{} 2021 muradm@* Copyright @copyright{} 2021 Andrew Tropin@* Copyright @copyright{} 2021 Sarah Morgensen@* Copyright @copyright{} 2022 Remco van 't Veer@* @@ -18227,6 +18228,142 @@ about the Pluggable Authentication Module (PAM) limits, refer to the @samp{pam_limits} man page from the @code{linux-pam} package. @end deffn +@defvr {Scheme Variable} greetd-service-type +@uref{https://git.sr.ht/~kennylevinsen/greetd, @code{greetd}} is a minimal and +flexible login manager daemon, that makes no assumptions about what you +want to launch. + +If you can run it from your shell in a TTY, greetd can start it. If it +can be taught to speak a simple JSON-based IPC protocol, then it can be +a geeter. + +@code{greetd-service-type} provides necessary infrastructure for logging +in users, including: + +@itemize @bullet +@item +@code{greetd} PAM service + +@item +Special variation of @code{pam-mount} to mount @code{XDG_RUNTIME_DIR} +@end itemize + +Here is example of switching from @code{mingetty-service-type} to +@code{greetd-service-type}, and how different terminals could be: + +@lisp + (append + (modify-services %base-services + ;; greetd-service-type provides "greetd" PAM service + (delete login-service-type) + ;; and can be used in place of mingetty-service-type + (delete mingetty-service-type)) + (list + (service greetd-service-type + (greetd-configuration + (terminals + (list + ;; we can make any terminal active by default + (greetd-terminal-configuration (terminal-vt "1") (terminal-switch #t)) + ;; we can make environment without XDG_RUNTIME_DIR set + ;; even provide our own environment variables + (greetd-terminal-configuration + (terminal-vt "2") + (default-session-command + (greetd-agreety-session + (extra-env '(("MY_VAR" . "1"))) + (xdg-env? #f)))) + ;; we can use different shell instead of default bash + (greetd-terminal-configuration + (terminal-vt "3") + (default-session-command + (greetd-agreety-session (command (file-append zsh "/bin/zsh"))))) + ;; we can use any other executable command as greeter + (greetd-terminal-configuration + (terminal-vt "4") + (default-session-command (program-file "my-noop-greeter" #~(exit)))) + (greetd-terminal-configuration (terminal-vt "5")) + (greetd-terminal-configuration (terminal-vt "6")))))) + ;; mingetty-service-type can be used in parallel + ;; if needed to do so, do not (delete login-service-type) + ;; as illustrated above + #| (service mingetty-service-type (mingetty-configuration (tty "tty8"))) |#)) +@end lisp +@end defvr + +@deftp {Data Type} greetd-configuration +Configuration record for the @code{greetd-service-type}. +@table @asis + +@item @code{motd} +A file-like object containing the ``message of the day''. + +@item @code{allow-empty-passwords?} (default: @code{#t}) +Allow empty passwords by default so that first-time users can log in when +the 'root' account has just been created. + +@item @code{terminals} (default: @code{'()}) +List of @code{greetd-terminal-configuration} per terminal for which +@code{greetd} should be started. +@end table +@end deftp + +@deftp {Data Type} greetd-terminal-configuration +Configuration record for per terminal greetd daemon service. + +@table @asis +@item @code{greetd} (default: @code{greetd}) +The greetd package to use. + +@item @code{config-file-name} +Configuration file name to use for greetd daemon. Generally, autogenerated +derivation based on @code{terminal-vt} value. + +@item @code{log-file-name} +Log file name to use for greetd daemon. Generally, autogenerated +name based on @code{terminal-vt} value. + +@item @code{terminal-vt} (default: @samp{"7"}) +The VT to run on. Use of a specific VT with appropriate conflict avoidance +is recommended. + +@item @code{terminal-switch} (default: @code{#f}) +Make this terminal active on start of @code{greetd}. + +@item @code{default-session-user} (default: @samp{"greeter"}) +The user to use for running the greeter. + +@item @code{default-session-command} (default: @code{(greetd-agreety-session)}) +Can be either instance of @code{greetd-agreety-session} configuration or +@code{gexp->script} like object to use as greeter. + +@end table +@end deftp + +@deftp {Data Type} greetd-agreety-session +Configuration record for the agreety greetd greeter. + +@table @asis +@item @code{agreety} (default: @code{greetd}) +The package with @command{/bin/agreety} command. + +@item @code{command} (default: @code{(file-append bash "/bin/bash")}) +Command to be started by @command{/bin/agreety} on successful login. + +@item @code{command-args} (default: @code{'("-l")}) +Command arguments to pass to command. + +@item @code{extra-env} (default: @code{'()}) +Extra environment variables to set on login. + +@item @code{xdg-env?} (default: @code{#t}) +If true @code{XDG_RUNTIME_DIR} and @code{XDG_SESSION_TYPE} will be set +before starting command. One should note that, @code{extra-env} variables +are set right after mentioned variables, so that they can be overriden. + +@end table +@end deftp + @node Scheduled Job Execution @subsection Scheduled Job Execution diff --git a/gnu/services/base.scm b/gnu/services/base.scm index ebbe4e128d..d58afb27e3 100644 --- a/gnu/services/base.scm +++ b/gnu/services/base.scm @@ -16,6 +16,7 @@ ;;; Copyright © 2021 qblade ;;; Copyright © 2021 Hui Lu ;;; Copyright © 2021, 2022 Maxim Cournoyer +;;; Copyright © 2021 muradm ;;; Copyright © 2022 Guillaume Le Vaillant ;;; Copyright © 2022 Justin Veilleux ;;; @@ -226,6 +227,11 @@ (define-module (gnu services base) pam-limits-service-type pam-limits-service + greetd-service-type + greetd-configuration + greetd-terminal-configuration + greetd-agreety-session + %base-services)) ;;; Commentary: @@ -1446,7 +1452,7 @@ (define pam-limits-service-type (module "pam_limits.so") (arguments '("conf=/etc/security/limits.conf"))))) (if (member (pam-service-name pam) - '("login" "su" "slim" "gdm-password" "sddm" + '("login" "greetd" "su" "slim" "gdm-password" "sddm" "sudo" "sshd")) (pam-service (inherit pam) @@ -2806,6 +2812,221 @@ (define %qemu-static-networking (provision '(networking)) (name-servers '("10.0.2.3")))) + +;;; +;;; greetd-service-type -- minimal and flexible login manager daemon +;;; + +(define-record-type* + greetd-agreety-session make-greetd-agreety-session + greetd-agreety-session? + (agreety greetd-agreety (default greetd)) + (command greetd-agreety-command (default (file-append bash "/bin/bash"))) + (command-args greetd-agreety-command-args (default '("-l"))) + (extra-env greetd-agreety-extra-env (default '())) + (xdg-env? greetd-agreety-xdg-env? (default #t))) + +(define greetd-agreety-tty-session-command + (match-lambda + (($ _ command args extra-env) + (program-file + "agreety-tty-session-command" + #~(begin + (use-modules (ice-9 match)) + (for-each (match-lambda ((var . val) (setenv var val))) + (quote (#$@extra-env))) + (apply execl #$command #$command (list #$@args))))))) + +(define greetd-agreety-tty-xdg-session-command + (match-lambda + (($ _ command args extra-env) + (program-file + "agreety-tty-xdg-session-command" + #~(begin + (use-modules (ice-9 match)) + (let* + ((username (getenv "USER")) + (useruid (passwd:uid (getpwuid username))) + (useruid (number->string useruid))) + (setenv "XDG_SESSION_TYPE" "tty") + (setenv "XDG_RUNTIME_DIR" (string-append "/run/user/" useruid))) + (for-each (match-lambda ((var . val) (setenv var val))) + (quote (#$@extra-env))) + (apply execl #$command #$command (list #$@args))))))) + +(define (make-greetd-agreety-session-command config command) + (let ((agreety (file-append (greetd-agreety config) "/bin/agreety"))) + (program-file + "agreety-command" + #~(execl #$agreety #$agreety "-c" #$command)))) + +(define (make-greetd-default-session-command config-or-command) + (cond ((greetd-agreety-session? config-or-command) + (cond ((greetd-agreety-xdg-env? config-or-command) + (make-greetd-agreety-session-command + config-or-command + (greetd-agreety-tty-xdg-session-command config-or-command))) + (#t + (make-greetd-agreety-session-command + config-or-command + (greetd-agreety-tty-session-command config-or-command))))) + (#t config-or-command))) + +(define-record-type* + greetd-terminal-configuration make-greetd-terminal-configuration + greetd-terminal-configuration? + (greetd greetd-package (default greetd)) + (config-file-name greetd-config-file-name (thunked) + (default (default-config-file-name this-record))) + (log-file-name greetd-log-file-name (thunked) + (default (default-log-file-name this-record))) + (terminal-vt greetd-terminal-vt (default "7")) + (terminal-switch greetd-terminal-switch (default #f)) + (default-session-user greetd-default-session-user (default "greeter")) + (default-session-command greetd-default-session-command + (default (greetd-agreety-session)) + (sanitize make-greetd-default-session-command))) + +(define (default-config-file-name config) + (string-join (list "config-" (greetd-terminal-vt config) ".toml") "")) + +(define (default-log-file-name config) + (string-join (list "/var/log/greetd-" (greetd-terminal-vt config) ".log") "")) + +(define (make-greetd-terminal-configuration-file config) + (let* + ((config-file-name (greetd-config-file-name config)) + (terminal-vt (greetd-terminal-vt config)) + (terminal-switch (greetd-terminal-switch config)) + (default-session-user (greetd-default-session-user config)) + (default-session-command (greetd-default-session-command config))) + (mixed-text-file + config-file-name + "[terminal]\n" + "vt = " terminal-vt "\n" + "switch = " (if terminal-switch "true" "false") "\n" + "[default_session]\n" + "user = " default-session-user "\n" + "command = " default-session-command "\n"))) + +(define %greetd-accounts + (list (user-account + (name "greeter") + (group "wheel") + (supplementary-groups '("users" "tty" "input" "video" "audio")) + (system? #t)))) + +(define %greetd-file-systems + (list (file-system + (device "none") + (mount-point "/run/greetd/pam_mount") + (type "tmpfs") + (check? #f) + (flags '(no-suid no-dev no-exec)) + (options "mode=0755") + (create-mount-point? #t)))) + +(define %greetd-pam-mount-rules + `((debug (@ (enable "0"))) + (volume (@ (sgrp "users") + (fstype "tmpfs") + (mountpoint "/run/user/%(USERUID)") + (options "noexec,nosuid,nodev,size=1g,mode=0700,uid=%(USERUID),gid=%(USERGID)"))) + (logout (@ (wait "0") + (hup "0") + (term "yes") + (kill "no"))) + (mkmountpoint (@ (enable "1") (remove "true"))))) + +(define-record-type* + greetd-configuration make-greetd-configuration + greetd-configuration? + (motd greetd-motd (default %default-motd)) + (allow-empty-passwords? greetd-allow-empty-passwords? (default #t)) + (terminals greetd-terminals (default '()))) + +(define (make-greetd-pam-mount-conf-file config) + (computed-file + "greetd_pam_mount.conf.xml" + #~(begin + (use-modules (sxml simple)) + (call-with-output-file #$output + (lambda (port) + (sxml->xml + '(*TOP* + (*PI* xml "version='1.0' encoding='utf-8'") + (pam_mount + #$@%greetd-pam-mount-rules + (pmvarrun + #$(file-append greetd-pam-mount + "/sbin/pmvarrun -u '%(USER)' -o '%(OPERATION)'")))) + port)))))) + +(define (greetd-etc-service config) + `(("security/greetd_pam_mount.conf.xml" + ,(make-greetd-pam-mount-conf-file config)))) + +(define (greetd-pam-service config) + (define optional-pam-mount + (pam-entry + (control "optional") + (module #~(string-append #$greetd-pam-mount "/lib/security/pam_mount.so")) + (arguments '("disable_interactive")))) + + (list + (unix-pam-service "greetd" + #:login-uid? #t + #:allow-empty-passwords? + (greetd-allow-empty-passwords? config) + #:motd + (greetd-motd config)) + (lambda (pam) + (if (member (pam-service-name pam) + '("login" "greetd" "su" "slim" "gdm-password")) + (pam-service + (inherit pam) + (auth (append (pam-service-auth pam) + (list optional-pam-mount))) + (session (append (pam-service-session pam) + (list optional-pam-mount)))) + pam)))) + +(define (greetd-shepherd-services config) + (map + (lambda (tc) + (let* + ((greetd-bin (file-append (greetd-package tc) "/sbin/greetd")) + (greetd-conf (make-greetd-terminal-configuration-file tc)) + (greetd-log (greetd-log-file-name tc)) + (greetd-vt (greetd-terminal-vt tc))) + (shepherd-service + (documentation "Minimal and flexible login manager daemon") + (requirement '(user-processes host-name udev virtual-terminal)) + (provision (list (symbol-append + 'term-tty + (string->symbol (greetd-terminal-vt tc))))) + (start #~(make-forkexec-constructor + (list #$greetd-bin "-c" #$greetd-conf) + #:log-file #$greetd-log)) + (stop #~(make-kill-destructor))))) + (greetd-terminals config))) + +(define greetd-service-type + (service-type + (name 'greetd) + (description "Provides necessary infrastructure for logging into the +system including @code{greetd} PAM service, @code{pam-mount} module to +mount/unmount /run/user/ directory for user and @code{greetd} +login manager daemon.") + (extensions + (list + (service-extension account-service-type (const %greetd-accounts)) + (service-extension file-system-service-type (const %greetd-file-systems)) + (service-extension etc-service-type greetd-etc-service) + (service-extension pam-root-service-type greetd-pam-service) + (service-extension shepherd-root-service-type greetd-shepherd-services))) + (default-value (greetd-configuration)))) + (define %base-services ;; Convenience variable holding the basic services. diff --git a/gnu/services/pam-mount.scm b/gnu/services/pam-mount.scm index 33649b0f7c..e60781d05b 100644 --- a/gnu/services/pam-mount.scm +++ b/gnu/services/pam-mount.scm @@ -90,7 +90,7 @@ (define optional-pam-mount (module #~(string-append #$pam-mount "/lib/security/pam_mount.so")))) (list (lambda (pam) (if (member (pam-service-name pam) - '("login" "su" "slim" "gdm-password" "sddm")) + '("login" "greetd" "su" "slim" "gdm-password" "sddm")) (pam-service (inherit pam) (auth (append (pam-service-auth pam)