;;; GNU Guix --- Functional package management for GNU ;;; Copyright © 2018, 2019 Mathieu Othacehe ;;; Copyright © 2020 Ludovic Courtès ;;; ;;; 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 . (define-module (gnu installer steps) #:use-module (guix records) #:use-module (guix build utils) #:use-module (g
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define-condition-type &installer-step-abort &condition installer-step-abort?) ;; This condition may be raised to break out from the steps execution. (define-condition-type &installer-step-break &condition installer-step-break?) ;; An installer-step record is basically an id associated to a compute ;; procedure. The COMPUTE procedure takes exactly one argument, an association ;; list containing the results of previously executed installer-steps (see ;; RUN-INSTALLER-STEPS description). The value returned by the COMPUTE ;; procedure will be stored in the results list passed to the next ;; installer-step and so on. (define-record-type* installer-step make-installer-step installer-step? (id installer-step-id) ;symbol (description installer-step-description ;string (default #f) ;; Make it thunked so that 'G_' is called at the ;; right time, as opposed to being called once ;; when the installer starts. (thunked)) (compute installer-step-compute) ;procedure (configuration-formatter installer-step-configuration-formatter ;procedure (default #f))) (define* (run-installer-steps #:key steps (rewind-strategy 'previous) (menu-proc (const #f))) "Run the COMPUTE procedure of all records in STEPS sequentially. If the &installer-step-abort condition is raised, fallback to a previous install-step, accordingly to the specified REWIND-STRATEGY. REWIND-STRATEGY possible values are 'previous, 'menu and 'start. If 'previous is selected, the execution will resume at the previous installer-step. If 'menu is selected, the MENU-PROC procedure will be called. Its return value has to be an installer-step ID to jump to. The ID has to be the one of a previously executed step. It is impossible to jump forward. Finally if 'start is selected, the execution will resume at the first installer-step. The result of every COMPUTE procedures is stored in an association list, under the form: '((STEP-ID . COMPUTE-RESULT) ...) where STEP-ID is the ID field of the installer-step and COMPUTE-RESULT the result of the associated COMPUTE procedure. This result association list is passed as argument of every COMPUTE procedure. It is finally returned when the computation is over. If the &installer-step-break condition is raised, stop the computation and return the accumalated result so far." (define (pop-result list) (cdr list)) (define (first-step? steps step) (match steps ((first-step . rest-steps) (equal? first-step step)))) (define* (skip-to-step step result #:key todo-steps done-steps) (match todo-steps ((todo . rest-todo) (let ((found? (eq? (installer-step-id todo) (installer-step-id step)))) (cond (found? (run result #:todo-steps todo-steps #:done-steps done-steps)) ((and (not found?) (null? done-steps)) (error (format #f "Step ~a not found" (installer-step-id step)))) (else (match done-steps ((prev-done ... last-done) (skip-to-step step (pop-result result) #:todo-steps (cons last-done todo-steps) #:done-steps prev-done))))))))) (define* (run result #:key todo-steps done-steps) (match todo-steps (() (reverse result)) ((step . rest-steps) (guard (c ((installer-step-abort? c) (case rewind-strategy ((previous) (match done-steps (() ;; We cannot go previous the first step. So re-raise ;; the exception. It might be useful in the case of ;; nested run-installer-steps. Abort to 'raise-above ;; prompt to prevent the condition from being catched ;; by one of the previously installed guard. (abort-to-prompt 'raise-above c)) ((prev-done ... last-done) (run (pop-result result) #:todo-steps (cons last-done todo-steps) #:done-steps prev-done)))) ((menu) (let ((goto-step (menu-proc (append done-steps (list step))))) (if (eq? goto-step step) (run result #:todo-steps todo-steps #:done-steps done-steps) (skip-to-step goto-step result #:todo-steps todo-steps #:done-steps done-steps)))) ((start) (if (null? done-steps) ;; Same as above, it makes no sense to jump to start ;; when we are at the first installer-step. Abort to ;; 'raise-above prompt to re-raise the condition. (abort-to-prompt 'raise-above c) (run '() #:todo-steps steps #:done-steps '()))))) ((installer-step-break? c) (reverse result))) (syslog "running step '~a'~%" (installer-step-id step)) (let* ((id (installer-step-id step)) (compute (installer-step-compute step)) (res (compute result done-steps))) (run (alist-cons id res result) #:todo-steps rest-steps #:done-steps (append done-steps (list step)))))))) ;; Ignore SIGPIPE so that we don't die if a client closes the connection ;; prematurely. (sigaction SIGPIPE SIG_IGN) (with-server-socket (call-with-prompt 'raise-above (lambda () (run '() #:todo-steps steps #:done-steps '())) (lambda (k condition) (raise condition))))) (define (find-step-by-id steps id) "Find and return the step in STEPS whose id is equal to ID." (find (lambda (step) (eq? (installer-step-id step) id)) steps)) (define (result-step results step-id) "Return the result of the installer-step specified by STEP-ID in RESULTS." (assoc-ref results step-id)) (define (result-step-done? results step-id) "Return #t if the installer-step specified by STEP-ID has a COMPUTE value stored in RESULTS. Return #f otherwise." (and (assoc step-id results) #t)) (define %installer-configuration-file (make-parameter "/mnt/etc/config.scm")) (define %installer-target-dir (make-parameter "/mnt")) (define (format-configuration steps results) "Return the list resulting from the application of the procedure defined in CONFIGURATION-FORMATTER field of on the associated result found in RESULTS." (let ((configuration (append-map (lambda (step) (let* ((step-id (installer-step-id step)) (conf-formatter (installer-step-configuration-formatter step)) (result-step (result-step results step-id))) (if (and result-step conf-formatter) (conf-formatter result-step) '()))) steps)) (modules '((use-modules (gnu)) (use-service-modules desktop networking ssh xorg)))) `(,@modules () (operating-system ,@configuration)))) (define* (configuration->file configuration #:key (filename (%installer-configuration-file))) "Write the given CONFIGURATION to FILENAME." (mkdir-p (dirname filename)) (call-with-output-file filename (lambda (port) (format port ";; This is an operating system configuration generated~%") (format port ";; by the graphical installer.~%") (newline port) (for-each (lambda (part) (if (null? part) (newline port) (pretty-print part port))) configuration) (flush-output-port port)))) ;;; Local Variables: ;;; eval: (put 'with-server-socket 'scheme-indent-function 0) ;;; End: