guix-devel/guix/scripts/substitute-binary.scm

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;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2013 Ludovic Courtès <ludo@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 substitute-binary)
#:use-module (guix ui)
#:use-module (guix store)
#:use-module (guix utils)
#:use-module (guix config)
#:use-module (guix nar)
#:use-module (ice-9 rdelim)
#:use-module (ice-9 regex)
#:use-module (ice-9 match)
#:use-module (ice-9 threads)
#:use-module (ice-9 format)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-9)
#:use-module (srfi srfi-11)
#:use-module (srfi srfi-26)
#:use-module (web uri)
#:use-module (web client)
#:use-module (web response)
#:export (guix-substitute-binary))
;;; Comment:
;;;
;;; This is the "binary substituter". It is invoked by the daemon do check
;;; for the existence of available "substitutes" (pre-built binaries), and to
;;; actually use them as a substitute to building things locally.
;;;
;;; If possible, substitute a binary for the requested store path, using a Nix
;;; "binary cache". This program implements the Nix "substituter" protocol.
;;;
;;; Code:
(define (fields->alist port)
"Read recutils-style record from PORT and return them as a list of key/value
pairs."
(define field-rx
(make-regexp "^([[:graph:]]+): (.*)$"))
(let loop ((line (read-line port))
(result '()))
(cond ((eof-object? line)
(reverse result))
((regexp-exec field-rx line)
=>
(lambda (match)
(loop (read-line port)
(alist-cons (match:substring match 1)
(match:substring match 2)
result))))
(else
(error "unmatched line" line)))))
(define (alist->record alist make keys)
"Apply MAKE to the values associated with KEYS in ALIST."
(let ((args (map (cut assoc-ref alist <>) keys)))
(apply make args)))
(define (fetch uri)
"Return a binary input port to URI and the number of bytes it's expected to
provide."
(case (uri-scheme uri)
((file)
(let ((port (open-input-file (uri-path uri))))
(values port (stat:size (stat port)))))
((http)
(let*-values (((resp port)
;; XXX: `http-get*' was introduced in 2.0.7, and deprecated
;; in 2.0.8 (!). Assume it is available here.
(if (version>? "2.0.7" (version))
(http-get* uri #:decode-body? #f)
(http-get uri #:streaming? #t)))
((code)
(response-code resp))
((size)
(response-content-length resp)))
(case code
((200) ; OK
(values port size))
((301 ; moved permanently
302) ; found (redirection)
(let ((uri (response-location resp)))
(format #t "following redirection to `~a'...~%"
(uri->string uri))
(fetch uri)))
(else
(error "download failed" (uri->string uri)
code (response-reason-phrase resp))))))))
(define-record-type <cache>
(%make-cache url store-directory wants-mass-query?)
cache?
(url cache-url)
(store-directory cache-store-directory)
(wants-mass-query? cache-wants-mass-query?))
(define (open-cache url)
"Open the binary cache at URL. Return a <cache> object on success, or #f on
failure."
(define (download-cache-info url)
;; Download the `nix-cache-info' from URL, and return its contents as an
;; list of key/value pairs.
(and=> (false-if-exception (fetch (string->uri url)))
fields->alist))
(and=> (download-cache-info (string-append url "/nix-cache-info"))
(lambda (properties)
(alist->record properties
(cut %make-cache url <...>)
'("StoreDir" "WantMassQuery")))))
(define-record-type <narinfo>
(%make-narinfo path uri compression file-hash file-size nar-hash nar-size
references deriver system)
narinfo?
(path narinfo-path)
(uri narinfo-uri)
(compression narinfo-compression)
(file-hash narinfo-file-hash)
(file-size narinfo-file-size)
(nar-hash narinfo-hash)
(nar-size narinfo-size)
(references narinfo-references)
(deriver narinfo-deriver)
(system narinfo-system))
(define (narinfo-maker cache-url)
"Return a narinfo constructor for narinfos originating from CACHE-URL."
(lambda (path url compression file-hash file-size nar-hash nar-size
references deriver system)
"Return a new <narinfo> object."
(%make-narinfo path
;; Handle the case where URL is a relative URL.
(or (string->uri url)
(string->uri (string-append cache-url "/" url)))
compression file-hash
(and=> file-size string->number)
nar-hash
(and=> nar-size string->number)
(string-tokenize references)
(match deriver
((or #f "") #f)
(_ deriver))
system)))
(define (fetch-narinfo cache path)
"Return the <narinfo> record for PATH, or #f if CACHE does not hold PATH."
(define (download url)
;; Download the `nix-cache-info' from URL, and return its contents as an
;; list of key/value pairs.
(and=> (false-if-exception (fetch (string->uri url)))
fields->alist))
(and=> (download (string-append (cache-url cache) "/"
(store-path-hash-part path)
".narinfo"))
(lambda (properties)
(alist->record properties (narinfo-maker (cache-url cache))
'("StorePath" "URL" "Compression"
"FileHash" "FileSize" "NarHash" "NarSize"
"References" "Deriver" "System")))))
(define (filtered-port command input)
"Return an input port (and PID) where data drained from INPUT is filtered
through COMMAND. INPUT must be a file input port."
(let ((i+o (pipe)))
(match (primitive-fork)
(0
(close-port (car i+o))
(close-port (current-input-port))
(dup2 (fileno input) 0)
(close-port (current-output-port))
(dup2 (fileno (cdr i+o)) 1)
(apply execl (car command) command))
(child
(close-port (cdr i+o))
(values (car i+o) child)))))
(define (decompressed-port compression input)
"Return an input port where INPUT is decompressed according to COMPRESSION."
(match compression
("none" (values input #f))
("bzip2" (filtered-port `(,%bzip2 "-dc") input))
("xz" (filtered-port `(,%xz "-dc") input))
("gzip" (filtered-port `(,%gzip "-dc") input))
(else (error "unsupported compression scheme" compression))))
(define %cache-url
(or (getenv "GUIX_BINARY_SUBSTITUTE_URL")
"http://hydra.gnu.org"))
;;;
;;; Entry point.
;;;
(define (guix-substitute-binary . args)
"Implement the build daemon's substituter protocol."
(match args
(("--query")
(let ((cache (open-cache %cache-url)))
(let loop ((command (read-line)))
(or (eof-object? command)
(begin
(match (string-tokenize command)
(("have" paths ..1)
;; Return the subset of PATHS available in CACHE.
(let ((substitutable
(if cache
(par-map (cut fetch-narinfo cache <>)
paths)
'())))
(for-each (lambda (narinfo)
(when narinfo
(format #t "~a~%" (narinfo-path narinfo))))
(filter narinfo? substitutable))
(newline)))
(("info" paths ..1)
;; Reply info about PATHS if it's in CACHE.
(let ((substitutable
(if cache
(par-map (cut fetch-narinfo cache <>)
paths)
'())))
(for-each (lambda (narinfo)
(format #t "~a\n~a\n~a\n"
(narinfo-path narinfo)
(or (and=> (narinfo-deriver narinfo)
(cute string-append
(%store-prefix) "/"
<>))
"")
(length (narinfo-references narinfo)))
(for-each (cute format #t "~a/~a~%"
(%store-prefix) <>)
(narinfo-references narinfo))
(format #t "~a\n~a\n"
(or (narinfo-file-size narinfo) 0)
(or (narinfo-size narinfo) 0)))
(filter narinfo? substitutable))
(newline)))
(wtf
(error "unknown `--query' command" wtf)))
(loop (read-line)))))))
(("--substitute" store-path destination)
;; Download STORE-PATH and add store it as a Nar in file DESTINATION.
(let* ((cache (open-cache %cache-url))
(narinfo (fetch-narinfo cache store-path))
(uri (narinfo-uri narinfo)))
;; Tell the daemon what the expected hash of the Nar itself is.
(format #t "~a~%" (narinfo-hash narinfo))
(let*-values (((raw download-size)
(fetch uri))
((input pid)
(decompressed-port (narinfo-compression narinfo)
raw)))
;; Note that Hydra currently generates Nars on the fly and doesn't
;; specify a Content-Length, so DOWNLOAD-SIZE is #f in practice.
(format (current-error-port)
(_ "downloading `~a' from `~a'~:[~*~; (~,1f KiB)~]...~%")
store-path (uri->string uri)
download-size
(and=> download-size (cut / <> 1024.0)))
;; Unpack the Nar at INPUT into DESTINATION.
(restore-file input destination)
(or (not pid) (zero? (cdr (waitpid pid)))))))
(("--version")
(show-version-and-exit "guix substitute-binary"))))
;;; substitute-binary.scm ends here