From 37ce440dcffa9ff4f5401bacbc9619bd8ea561c1 Mon Sep 17 00:00:00 2001 From: Ludovic Courtès Date: Tue, 17 Oct 2017 10:34:03 +0200 Subject: download: Download a nar when a VCS checkout fails. Fixes . * guix/build/download-nar.scm: New file. * Makefile.am (MODULES): Add it. * guix/cvs-download.scm (cvs-fetch)[zlib, config.scm, modules]: New variables. [build]: Use MODULES. Add call to 'download-nar'. * guix/git-download.scm (git-fetch): Likewise. * guix/hg-download.scm (hg-fetch): Likewise. --- guix/build/download-nar.scm | 125 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 125 insertions(+) create mode 100644 guix/build/download-nar.scm (limited to 'guix/build/download-nar.scm') diff --git a/guix/build/download-nar.scm b/guix/build/download-nar.scm new file mode 100644 index 0000000000..13f01fb1e8 --- /dev/null +++ b/guix/build/download-nar.scm @@ -0,0 +1,125 @@ +;;; GNU Guix --- Functional package management for GNU +;;; Copyright © 2017 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 (guix build download-nar) + #:use-module (guix build download) + #:use-module (guix build utils) + #:use-module (guix serialization) + #:use-module (guix zlib) + #:use-module (guix progress) + #:use-module (web uri) + #:use-module (srfi srfi-11) + #:use-module (srfi srfi-26) + #:use-module (ice-9 format) + #:use-module (ice-9 match) + #:export (download-nar)) + +;;; Commentary: +;;; +;;; Download a normalized archive or "nar", similar to what 'guix substitute' +;;; does. The intent here is to use substitute servers as content-addressed +;;; mirrors of VCS checkouts. This is mostly useful for users who have +;;; disabled substitutes. +;;; +;;; Code: + +(define (urls-for-item item) + "Return the fallback nar URL for ITEM--e.g., +\"/gnu/store/cabbag3…-foo-1.2-checkout\"." + ;; Here we hard-code nar URLs without checking narinfos. That's probably OK + ;; though. + ;; TODO: Use HTTPS? The downside is the extra dependency. + (let ((bases '("http://mirror.hydra.gnu.org/guix" + "http://berlin.guixsd.org")) + (item (basename item))) + (append (map (cut string-append <> "/nar/gzip/" item) bases) + (map (cut string-append <> "/nar/" item) bases)))) + +(define (restore-gzipped-nar port item size) + "Restore the gzipped nar read from PORT, of SIZE bytes (compressed), to +ITEM." + ;; Since PORT is typically a non-file port (for instance because 'http-get' + ;; returns a delimited port), create a child process so we're back to a file + ;; port that can be passed to 'call-with-gzip-input-port'. + (match (pipe) + ((input . output) + (match (primitive-fork) + (0 + (dynamic-wind + (const #t) + (lambda () + (close-port output) + (close-port port) + (catch #t + (lambda () + (call-with-gzip-input-port input + (cut restore-file <> item))) + (lambda (key . args) + (print-exception (current-error-port) + (stack-ref (make-stack #t) 1) + key args) + (primitive-exit 1)))) + (lambda () + (primitive-exit 0)))) + (child + (close-port input) + (dump-port* port output + #:reporter (progress-reporter/file item size + #:abbreviation + store-path-abbreviation)) + (close-port output) + (newline) + (match (waitpid child) + ((_ . status) + (unless (zero? status) + (error "nar decompression failed" status))))))))) + +(define (download-nar item) + "Download and extract the normalized archive for ITEM. Return #t on +success, #f otherwise." + ;; Let progress reports go through. + (setvbuf (current-error-port) _IONBF) + (setvbuf (current-output-port) _IONBF) + + (let loop ((urls (urls-for-item item))) + (match urls + ((url rest ...) + (format #t "Trying content-addressed mirror at ~a...~%" + (uri-host (string->uri url))) + (let-values (((port size) + (catch #t + (lambda () + (http-fetch (string->uri url))) + (lambda args + (values #f #f))))) + (if (not port) + (loop rest) + (begin + (if size + (format #t "Downloading from ~a (~,2h MiB)...~%" url + (/ size (expt 2 20.))) + (format #t "Downloading from ~a...~%" url)) + (if (string-contains url "/gzip") + (restore-gzipped-nar port item size) + (begin + ;; FIXME: Add progress report. + (restore-file port item) + (close-port port))) + #t)))) + (() + #f)))) -- cgit v1.2.3