Mirror of GNU Guix
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;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2013, 2014, 2015, 2016 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2014 Nikita Karetnikov <nikita@karetnikov.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
;;; 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)
#:use-module (guix ui)
#:use-module ((guix store) #:hide (close-connection))
#:use-module (guix utils)
#:use-module (guix combinators)
#:use-module (guix config)
#:use-module (guix records)
#:use-module (guix serialization)
#:use-module (guix hash)
#:use-module (guix base32)
#:use-module (guix base64)
#:use-module (guix pk-crypto)
#:use-module (guix pki)
#:use-module ((guix build utils) #:select (mkdir-p dump-port))
#:use-module ((guix build download)
#:select (current-terminal-columns
progress-proc uri-abbreviation nar-uri-abbreviation
store-path-abbreviation byte-count->string))
#:use-module (ice-9 rdelim)
#:use-module (ice-9 regex)
#:use-module (ice-9 match)
#:use-module (ice-9 format)
#:use-module (ice-9 ftw)
#:use-module (ice-9 binary-ports)
#:use-module (rnrs io ports)
#:use-module (rnrs bytevectors)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-9)
#:use-module (srfi srfi-11)
#:use-module (srfi srfi-19)
#:use-module (srfi srfi-26)
#:use-module (srfi srfi-34)
#:use-module (srfi srfi-35)
#:use-module (web uri)
#:use-module (web http)
#:use-module (web request)
#:use-module (web response)
#:use-module (guix http-client)
#:export (narinfo-signature->canonical-sexp
;;; 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 %narinfo-cache-directory
;; A local cache of narinfos, to avoid going to the network. Most of the
;; time, 'guix substitute' is called by guix-daemon as root and stores its
;; cached data in /var/guix/…. However, when invoked from 'guix challenge'
;; as a user, it stores its cache in ~/.cache.
(if (zero? (getuid))
(or (and=> (getenv "XDG_CACHE_HOME")
(cut string-append <> "/guix/substitute"))
(string-append %state-directory "/substitute/cache"))
(string-append (cache-directory) "/substitute")))
(define %allow-unauthenticated-substitutes?
;; Whether to allow unchecked substitutes. This is useful for testing
;; purposes, and should be avoided otherwise.
(cut string-ci=? <> "yes"))
(warning (_ "authentication and authorization of substitutes \
(define %narinfo-ttl
;; Number of seconds during which cached narinfo lookups are considered
;; valid for substitute servers that do not advertise a TTL via the
;; 'Cache-Control' response header.
(* 36 3600))
(define %narinfo-negative-ttl
;; Likewise, but for negative lookups---i.e., cached lookup failures (404).
(* 3 3600))
(define %narinfo-transient-error-ttl
;; Likewise, but for transient errors such as 504 ("Gateway timeout").
(* 10 60))
(define %narinfo-expired-cache-entry-removal-delay
;; How often we want to remove files corresponding to expired cache entries.
(* 7 24 3600))
(define fields->alist
;; The narinfo format is really just like recutils.
(define %fetch-timeout
;; Number of seconds after which networking is considered "slow".
(define %random-state
(seed->random-state (+ (ash (cdr (gettimeofday)) 32) (getpid))))
(define-syntax-rule (with-timeout duration handler body ...)
"Run BODY; when DURATION seconds have expired, call HANDLER, and run BODY
(sigaction SIGALRM
(lambda (signum)
(sigaction SIGALRM SIG_DFL)
(alarm duration)
(lambda ()
(let try ()
(catch 'system-error
(lambda ()
body ...)
(lambda args
;; Before Guile v2.0.9-39-gfe51c7b, the SIGALRM triggers EINTR
;; because of the bug at
;; <http://lists.gnu.org/archive/html/guile-devel/2013-06/msg00050.html>.
;; When that happens, try again. Note: SA_RESTART cannot be
;; used because of <http://bugs.gnu.org/14640>.
(if (= EINTR (system-error-errno args))
;; Wait a little to avoid bursts.
(usleep (random 3000000 %random-state))
(apply throw args))))))
(lambda result
(alarm 0)
(sigaction SIGALRM SIG_DFL)
(apply values result)))))
(define* (fetch uri #:key (buffered? #t) (timeout? #t))
"Return a binary input port to URI and the number of bytes it's expected to
(case (uri-scheme uri)
(let ((port (open-file (uri-path uri)
(if buffered? "rb" "r0b"))))
(values port (stat:size (stat port)))))
((http https)
(guard (c ((http-get-error? c)
(leave (_ "download from '~a' failed: ~a, ~s~%")
(uri->string (http-get-error-uri c))
(http-get-error-code c)
(http-get-error-reason c))))
;; Test this with:
;; sudo tc qdisc add dev eth0 root netem delay 1500ms
;; and then cancel with:
;; sudo tc qdisc del dev eth0 root
(let ((port #f))
(with-timeout (if timeout?
(warning (_ "while fetching ~a: server is somewhat slow~%")
(uri->string uri))
(warning (_ "try `--no-substitutes' if the problem persists~%"))
;; Before Guile v2.0.9-39-gfe51c7b, EINTR was reported to the user,
;; and thus PORT had to be closed and re-opened. This is not the
;; case afterward.
(unless (or (guile-version>? "2.0.9")
(version>? (version) ""))
(when port
(close-connection port))))
(when (or (not port) (port-closed? port))
(set! port (open-connection-for-uri uri))
(unless (or buffered? (not (file-port? port)))
(setvbuf port _IONBF)))
(http-fetch uri #:text? #f #:port port))))))
(leave (_ "unsupported substitute URI scheme: ~a~%")
(uri->string uri)))))
(define-record-type <cache-info>
(%make-cache-info url store-directory wants-mass-query?)
(url cache-info-url)
(store-directory cache-info-store-directory)
(wants-mass-query? cache-info-wants-mass-query?))
(define (download-cache-info url)
"Download the information for the cache at URL. On success, return a
<cache-info> object and a port on which to send further HTTP requests. On
failure, return #f and #f."
(define uri
(string->uri (string-append url "/nix-cache-info")))
(define (read-cache-info port)
(alist->record (fields->alist port)
(cut %make-cache-info url <...>)
'("StoreDir" "WantMassQuery")))
(catch #t
(lambda ()
(case (uri-scheme uri)
(values (call-with-input-file (uri-path uri)
((http https)
(let ((port (open-connection-for-uri uri
#:timeout %fetch-timeout)))
(guard (c ((http-get-error? c)
(warning (_ "while fetching '~a': ~a (~s)~%")
(uri->string (http-get-error-uri c))
(http-get-error-code c)
(http-get-error-reason c))
(close-connection port)
(warning (_ "ignoring substitute server at '~s'~%") url)
(values #f #f)))
(values (read-cache-info (http-fetch uri
#:port port
#:keep-alive? #t))
(lambda (key . args)
(case key
((getaddrinfo-error system-error)
;; Silently ignore the error: probably due to lack of network access.
(values #f #f))
(apply throw key args))))))
(define-record-type <narinfo>
(%make-narinfo path uri uri-base compression file-hash file-size nar-hash nar-size
references deriver system signature contents)
(path narinfo-path)
(uri narinfo-uri)
(uri-base narinfo-uri-base) ; URI of the cache it originates from
(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)
(signature narinfo-signature) ; canonical sexp
;; The original contents of a narinfo file. This field is needed because we
;; want to preserve the exact textual representation for verification purposes.
;; See <https://lists.gnu.org/archive/html/guix-devel/2014-02/msg00340.html>
;; for more information.
(contents narinfo-contents))
(define (narinfo-hash->sha256 hash)
"If the string HASH denotes a sha256 hash, return it as a bytevector.
Otherwise return #f."
(and (string-prefix? "sha256:" hash)
(nix-base32-string->bytevector (string-drop hash 7))))
(define (narinfo-signature->canonical-sexp str)
"Return the value of a narinfo's 'Signature' field as a canonical sexp."
(match (string-split str #\;)
((version _ sig)
(let ((maybe-number (string->number version)))
(cond ((not (number? maybe-number))
(leave (_ "signature version must be a number: ~s~%")
;; Currently, there are no other versions.
((not (= 1 maybe-number))
(leave (_ "unsupported signature version: ~a~%")
(let ((signature (utf8->string (base64-decode sig))))
(catch 'gcry-error
(lambda ()
(string->canonical-sexp signature))
(lambda (key proc err)
(leave (_ "signature is not a valid \
s-expression: ~s~%")
(leave (_ "invalid format of the signature field: ~a~%") x))))
(define (narinfo-maker str cache-url)
"Return a narinfo constructor for narinfos originating from CACHE-URL. STR
must contain the original contents of a narinfo file."
(lambda (path url compression file-hash file-size nar-hash nar-size
references deriver system signature)
"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)
(and=> nar-size string->number)
(string-tokenize references)
(match deriver
((or #f "") #f)
(_ deriver))
(and=> signature narinfo-signature->canonical-sexp))
(define* (assert-valid-signature narinfo signature hash
#:optional (acl (current-acl)))
"Bail out if SIGNATURE, a canonical sexp representing the signature of
NARINFO, doesn't match HASH, a bytevector containing the hash of NARINFO."
(let ((uri (uri->string (narinfo-uri narinfo))))
(signature-case (signature hash acl)
(valid-signature #t)
(leave (_ "invalid signature for '~a'~%") uri))
(leave (_ "hash mismatch for '~a'~%") uri))
(leave (_ "'~a' is signed with an unauthorized key~%") uri))
(leave (_ "signature on '~a' is corrupt~%") uri)))))
(define* (read-narinfo port #:optional url
#:key size)
"Read a narinfo from PORT. If URL is true, it must be a string used to
build full URIs from relative URIs found while reading PORT. When SIZE is
true, read at most SIZE bytes from PORT; otherwise, read as much as possible.
No authentication and authorization checks are performed here!"
(let ((str (utf8->string (if size
(get-bytevector-n port size)
(get-bytevector-all port)))))
(alist->record (call-with-input-string str fields->alist)
(narinfo-maker str url)
'("StorePath" "URL" "Compression"
"FileHash" "FileSize" "NarHash" "NarSize"
"References" "Deriver" "System"
(define (narinfo-sha256 narinfo)
"Return the sha256 hash of NARINFO as a bytevector, or #f if NARINFO lacks a
'Signature' field."
(let ((contents (narinfo-contents narinfo)))
(match (string-contains contents "Signature:")
(#f #f)
(let ((above-signature (string-take contents index)))
(sha256 (string->utf8 above-signature)))))))
(define* (assert-valid-narinfo narinfo
#:optional (acl (current-acl))
#:key (verbose? #t))
"Raise an exception if NARINFO lacks a signature, has an invalid signature,
or is signed by an unauthorized key."
(let ((hash (narinfo-sha256 narinfo)))
(if (not hash)
(if %allow-unauthenticated-substitutes?
(leave (_ "substitute at '~a' lacks a signature~%")
(uri->string (narinfo-uri narinfo))))
(let ((signature (narinfo-signature narinfo)))
(unless %allow-unauthenticated-substitutes?
(assert-valid-signature narinfo signature hash acl)
(when verbose?
;; Visually separate substitutions with a newline.
(format (current-error-port)
(_ "~%Found valid signature for ~a~%")
(narinfo-path narinfo))
(format (current-error-port)
(_ "From ~a~%")
(uri->string (narinfo-uri narinfo)))))
(define* (valid-narinfo? narinfo #:optional (acl (current-acl)))
"Return #t if NARINFO's signature is not valid."
(or %allow-unauthenticated-substitutes?
(let ((hash (narinfo-sha256 narinfo))
(signature (narinfo-signature narinfo)))
(and hash signature
(signature-case (signature hash acl)
(valid-signature #t)
(else #f))))))
(define (write-narinfo narinfo port)
"Write NARINFO to PORT."
(put-bytevector port (string->utf8 (narinfo-contents narinfo))))
(define (narinfo->string narinfo)
"Return the external representation of NARINFO."
(call-with-output-string (cut write-narinfo narinfo <>)))
(define (string->narinfo str cache-uri)
"Return the narinfo represented by STR. Assume CACHE-URI as the base URI of
the cache STR originates form."
(call-with-input-string str (cut read-narinfo <> cache-uri)))
(define (obsolete? date now ttl)
"Return #t if DATE is obsolete compared to NOW + TTL seconds."
(time>? (subtract-duration now (make-time time-duration 0 ttl))
(make-time time-monotonic 0 date)))
(define (narinfo-cache-file cache-url path)
"Return the name of the local file that contains an entry for PATH. The
entry is stored in a sub-directory specific to CACHE-URL."
;; The daemon does not sanitize its input, so PATH could be something like
;; "/gnu/store/foo". Gracefully handle that.
(match (store-path-hash-part path)
(leave (_ "'~a' does not name a store item~%") path))
((? string? hash-part)
(string-append %narinfo-cache-directory "/"
(bytevector->base32-string (sha256 (string->utf8 cache-url)))
"/" hash-part))))
(define (cached-narinfo cache-url path)
"Check locally if we have valid info about PATH coming from CACHE-URL.
Return two values: a Boolean indicating whether we have valid cached info, and
that info, which may be either #f (when PATH is unavailable) or the narinfo
for PATH."
(define now
(current-time time-monotonic))
(define cache-file
(narinfo-cache-file cache-url path))
(catch 'system-error
(lambda ()
(call-with-input-file cache-file
(lambda (p)
(match (read p)
(('narinfo ('version 2)
('cache-uri cache-uri)
('date date) ('ttl _) ('value #f))
;; A cached negative lookup.
(if (obsolete? date now %narinfo-negative-ttl)
(values #f #f)
(values #t #f)))
(('narinfo ('version 2)
('cache-uri cache-uri)
('date date) ('ttl ttl) ('value value))
;; A cached positive lookup
(if (obsolete? date now ttl)
(values #f #f)
(values #t (string->narinfo value cache-uri))))
(('narinfo ('version v) _ ...)
(values #f #f))))))
(lambda _
(values #f #f))))
(define (cache-narinfo! cache-url path narinfo ttl)
"Cache locally NARNIFO for PATH, which originates from CACHE-URL, with the
given TTL (a number of seconds or #f). NARINFO may be #f, in which case it
indicates that PATH is unavailable at CACHE-URL."
(define now
(current-time time-monotonic))
(define (cache-entry cache-uri narinfo)
`(narinfo (version 2)
(cache-uri ,cache-uri)
(date ,(time-second now))
(ttl ,(or ttl
(if narinfo %narinfo-ttl %narinfo-negative-ttl)))
(value ,(and=> narinfo narinfo->string))))
(let ((file (narinfo-cache-file cache-url path)))
(mkdir-p (dirname file))
(with-atomic-file-output file
(lambda (out)
(write (cache-entry cache-url narinfo) out))))
(define (narinfo-request cache-url path)
"Return an HTTP request for the narinfo of PATH at CACHE-URL."
(let ((url (string-append cache-url "/" (store-path-hash-part path)
(build-request (string->uri url) #:method 'GET)))
(define* (http-multiple-get base-uri proc seed requests
#:key port)
"Send all of REQUESTS to the server at BASE-URI. Call PROC for each
response, passing it the request object, the response, a port from which to
read the response body, and the previous result, starting with SEED, à la
'fold'. Return the final result. When PORT is specified, use it as the
initial connection on which HTTP requests are sent."
(let connect ((port port)
(requests requests)
(result seed))
;; (format (current-error-port) "connecting (~a requests left)..."
;; (length requests))
(let ((p (or port (open-connection-for-uri base-uri))))
;; For HTTPS, P is not a file port and does not support 'setvbuf'.
(when (file-port? p)
(setvbuf p _IOFBF (expt 2 16)))
;; Send all of REQUESTS in a row.
;; XXX: Do our own caching to work around inefficiencies when
;; communicating over TLS: <http://bugs.gnu.org/22966>.
(let-values (((buffer get) (open-bytevector-output-port)))
;; On Guile > 2.0.9, inherit the HTTP proxying property from P.
(when (module-variable (resolve-interface '(web http))
(set-http-proxy-port?! buffer (http-proxy-port? p)))
(for-each (cut write-request <> buffer) requests)
(put-bytevector p (get))
(force-output p))
;; Now start processing responses.
(let loop ((requests requests)
(result result))
(match requests
(reverse result))
((head tail ...)
(let* ((resp (read-response p))
(body (response-body-port resp))
(result (proc head resp body result)))
;; The server can choose to stop responding at any time, in which
;; case we have to try again. Check whether that is the case.
;; Note that even upon "Connection: close", we can read from BODY.
(match (assq 'connection (response-headers resp))
(('connection 'close)
(close-connection p)
(connect #f tail result)) ;try again
(loop tail result)))))))))) ;keep going
(define (read-to-eof port)
"Read from PORT until EOF is reached. The data are discarded."
(dump-port port (%make-void-port "w")))
(define (narinfo-from-file file url)
"Attempt to read a narinfo from FILE, using URL as the cache URL. Return #f
if file doesn't exist, and the narinfo otherwise."
(catch 'system-error
(lambda ()
(call-with-input-file file
(cut read-narinfo <> url)))
(lambda args
(if (= ENOENT (system-error-errno args))
(apply throw args)))))
(define (fetch-narinfos url paths)
"Retrieve all the narinfos for PATHS from the cache at URL and return them."
(define update-progress!
(let ((done 0))
(lambda ()
(display #\cr (current-error-port))
(force-output (current-error-port))
(format (current-error-port)
(_ "updating list of substitutes from '~a'... ~5,1f%")
url (* 100. (/ done (length paths))))
(set! done (+ 1 done)))))
(define (handle-narinfo-response request response port result)
(let* ((code (response-code response))
(len (response-content-length response))
(cache (response-cache-control response))
(ttl (and cache (assoc-ref cache 'max-age))))
;; Make sure to read no more than LEN bytes since subsequent bytes may
;; belong to the next response.
(if (= code 200) ; hit
(let ((narinfo (read-narinfo port url #:size len)))
(cache-narinfo! url (narinfo-path narinfo) narinfo ttl)
(cons narinfo result))
(let* ((path (uri-path (request-uri request)))
(hash-part (string-drop-right path 8))) ; drop ".narinfo"
(if len
(get-bytevector-n port len)
(read-to-eof port))
(cache-narinfo! url
(find (cut string-contains <> hash-part) paths)
(if (= 404 code)
(define (do-fetch uri port)
(case (and=> uri uri-scheme)
((http https)
(let ((requests (map (cut narinfo-request url <>) paths)))
(let ((result (http-multiple-get uri
handle-narinfo-response '()
#:port port)))
(close-connection port)
(newline (current-error-port))
((file #f)
(let* ((base (string-append (uri-path uri) "/"))
(files (map (compose (cut string-append base <> ".narinfo")
(filter-map (cut narinfo-from-file <> url) files)))
(leave (_ "~s: unsupported server URI scheme~%")
(if uri (uri-scheme uri) url)))))
(let-values (((cache-info port)
(download-cache-info url)))
(and cache-info
(if (string=? (cache-info-store-directory cache-info)
(do-fetch (string->uri url) port) ;reuse PORT
(warning (_ "'~a' uses different store '~a'; ignoring it~%")
url (cache-info-store-directory cache-info))
(close-connection port)
(define (lookup-narinfos cache paths)
"Return the narinfos for PATHS, invoking the server at CACHE when no
information is available locally."
(let-values (((cached missing)
(fold2 (lambda (path cached missing)
(let-values (((valid? value)
(cached-narinfo cache path)))
(if valid?
(if value
(values (cons value cached) missing)
(values cached missing))
(values cached (cons path missing)))))
(if (null? missing)
(let ((missing (fetch-narinfos cache missing)))
(append cached (or missing '()))))))
(define (lookup-narinfos/diverse caches paths)
"Look up narinfos for PATHS on all of CACHES, a list of URLS, in that order.
That is, when a cache lacks a narinfo, look it up in the next cache, and so
on. Return a list of narinfos for PATHS or a subset thereof."
(let loop ((caches caches)
(paths paths)
(result '()))
(match paths
(() ;we're done
(match caches
((cache rest ...)
(let* ((narinfos (lookup-narinfos cache paths))
(hits (map narinfo-path narinfos))
(missing (lset-difference string=? paths hits))) ;XXX: perf
(loop rest missing (append narinfos result))))
(() ;that's it
(define (lookup-narinfo caches path)
"Return the narinfo for PATH in CACHES, or #f when no substitute for PATH
was found."
(match (lookup-narinfos/diverse caches (list path))
((answer) answer)
(_ #f)))
(define (remove-expired-cached-narinfos directory)
"Remove expired narinfo entries from DIRECTORY. The sole purpose of this
function is to make sure `%narinfo-cache-directory' doesn't grow
(define now
(current-time time-monotonic))
(define (expired? file)
(catch 'system-error
(lambda ()
(call-with-input-file file
(lambda (port)
(match (read port)
(('narinfo ('version 2) ('cache-uri _)
('date date) ('ttl _) ('value #f))
(obsolete? date now %narinfo-negative-ttl))
(('narinfo ('version 2) ('cache-uri _)
('date date) ('ttl ttl) ('value _))
(obsolete? date now ttl))
(_ #t)))))
(lambda args
;; FILE may have been deleted.
(for-each (lambda (file)
(let ((file (string-append directory "/" file)))
(when (expired? file)
;; Wrap in `false-if-exception' because FILE might have been
;; deleted in the meantime (TOCTTOU).
(false-if-exception (delete-file file)))))
(scandir directory
(lambda (file)
(= (string-length file) 32)))))
(define (narinfo-cache-directories)
"Return the list of narinfo cache directories (one per cache URL.)"
(map (cut string-append %narinfo-cache-directory "/" <>)
(scandir %narinfo-cache-directory
(lambda (item)
(and (not (member item '("." "..")))
(string-append %narinfo-cache-directory
"/" item)))))))
(define (maybe-remove-expired-cached-narinfo)
"Remove expired narinfo entries from the cache if deemed necessary."
(define now
(current-time time-monotonic))
(define expiry-file
(string-append %narinfo-cache-directory "/last-expiry-cleanup"))
(define last-expiry-date
(or (false-if-exception
(call-with-input-file expiry-file read))
(when (obsolete? last-expiry-date now
(for-each remove-expired-cached-narinfos
(call-with-output-file expiry-file
(cute write (time-second now) <>))))
(define (progress-report-port report-progress port)
"Return a port that calls REPORT-PROGRESS every time something is read from
PORT. REPORT-PROGRESS is a two-argument procedure such as that returned by
(define total 0)
(define (read! bv start count)
(let ((n (match (get-bytevector-n! port bv start count)
((? eof-object?) 0)
(x x))))
(set! total (+ total n))
(report-progress total (const n))
;; XXX: We're not in control, so we always return anyway.
(make-custom-binary-input-port "progress-port-proc"
read! #f #f
(cut close-connection port)))
(define-syntax with-networking
(syntax-rules ()
"Catch DNS lookup errors and TLS errors and gracefully exit."
;; Note: no attempt is made to catch other networking errors, because DNS
;; lookup errors are typically the first one, and because other errors are
;; a subset of `system-error', which is harder to filter.
((_ exp ...)
(catch #t
(lambda () exp ...)
(('getaddrinfo-error error)
(leave (_ "host name lookup error: ~a~%")
(gai-strerror error)))
(('gnutls-error error proc . rest)
(let ((error->string (module-ref (resolve-interface '(gnutls))
(leave (_ "TLS error in procedure '~a': ~a~%")
proc (error->string error))))
(apply throw args)))))))
;;; Help.
(define (show-help)
(display (_ "Usage: guix substitute [OPTION]...
Internal tool to substitute a pre-built binary to a local build.\n"))
(display (_ "
--query report on the availability of substitutes for the
store file names passed on the standard input"))
(display (_ "
download STORE-FILE and store it as a Nar in file
(display (_ "
-h, --help display this help and exit"))
(display (_ "
-V, --version display version information and exit"))
;;; Daemon/substituter protocol.
(define (display-narinfo-data narinfo)
"Write to the current output port the contents of NARINFO in the format
expected by the daemon."
(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)))
(define* (process-query command
#:key cache-urls acl)
"Reply to COMMAND, a query as written by the daemon to this process's
standard input. Use ACL as the access-control list against which to check
authorized substitutes."
(define (valid? obj)
(valid-narinfo? obj acl))
(match (string-tokenize command)
(("have" paths ..1)
;; Return the subset of PATHS available in CACHE-URLS.
(let ((substitutable (lookup-narinfos/diverse cache-urls paths)))
(for-each (lambda (narinfo)
(format #t "~a~%" (narinfo-path narinfo)))
(filter valid? substitutable))
(("info" paths ..1)
;; Reply info about PATHS if it's in CACHE-URLS.
(let ((substitutable (lookup-narinfos/diverse cache-urls paths)))
(for-each display-narinfo-data (filter valid? substitutable))
(error "unknown `--query' command" wtf))))
(define* (process-substitution store-item destination
#:key cache-urls acl)
"Substitute STORE-ITEM (a store file name) from CACHE-URLS, and write it to
DESTINATION as a nar file. Verify the substitute against ACL."
(let* ((narinfo (lookup-narinfo cache-urls store-item))
(uri (narinfo-uri narinfo)))
;; Make sure it is signed and everything.
(assert-valid-narinfo narinfo acl)
;; Tell the daemon what the expected hash of the Nar itself is.
(format #t "~a~%" (narinfo-hash narinfo))
(format (current-error-port)
;; TRANSLATORS: The second part of this message looks like
;; "(4.1MiB installed)"; it shows the size of the package once
;; installed.
(_ "Downloading ~a~:[~*~; (~a installed)~]...~%")
(store-path-abbreviation store-item)
;; Use the Nar size as an estimate of the installed size.
(narinfo-size narinfo)
(and=> (narinfo-size narinfo)
(cute byte-count->string <>)))
(let*-values (((raw download-size)
;; Note that Hydra currently generates Nars on the fly
;; and doesn't specify a Content-Length, so
;; DOWNLOAD-SIZE is #f in practice.
(fetch uri #:buffered? #f #:timeout? #f))
(let* ((comp (narinfo-compression narinfo))
(dl-size (or download-size
(and (equal? comp "none")
(narinfo-size narinfo))))
(progress (progress-proc (uri->string uri)
(progress-report-port progress raw)))
((input pids)
(decompressed-port (and=> (narinfo-compression narinfo)
;; Unpack the Nar at INPUT into DESTINATION.
(restore-file input destination)
;; Skip a line after what 'progress-proc' printed.
(newline (current-error-port))
(every (compose zero? cdr waitpid) pids))))
;;; Entry point.
(define (check-acl-initialized)
"Warn if the ACL is uninitialized."
(define (singleton? acl)
;; True if ACL contains just the user's public key.
(and (file-exists? %public-key-file)
(let ((key (call-with-input-file %public-key-file
(compose string->canonical-sexp
(match acl
(equal? (canonical-sexp->string thing)
(canonical-sexp->string key)))
(let ((acl (acl->public-keys (current-acl))))
(when (or (null? acl) (singleton? acl))
(warning (_ "ACL for archive imports seems to be uninitialized, \
substitutes may be unavailable\n")))))
(define (daemon-options)
"Return a list of name/value pairs denoting build daemon options."
(define %not-newline
(char-set-complement (char-set #\newline)))
(match (getenv "_NIX_OPTIONS")
(#f ;should not happen when called by the daemon
;; Here we get something of the form "OPTION1=VALUE1\nOPTION2=VALUE2\n".
(filter-map (lambda (option=value)
(match (string-index option=value #\=)
(#f ;invalid option setting
(cons (string-take option=value equal-sign)
(string-drop option=value (+ 1 equal-sign))))))
(string-tokenize newline-separated %not-newline)))))
(define (find-daemon-option option)
"Return the value of build daemon option OPTION, or #f if it could not be
(assoc-ref (daemon-options) option))
(define %cache-urls
(match (and=> (or (find-daemon-option "untrusted-substitute-urls") ;client
(find-daemon-option "substitute-urls")) ;admin
((urls ...)
;; This can only happen when this script is not invoked by the
;; daemon.
(define (client-terminal-columns)
"Return the number of columns in the client's terminal, if it is known, or a
default value."
(or (and=> (or (find-daemon-option "untrusted-terminal-columns")
(find-daemon-option "terminal-columns"))
(lambda (str)
(let ((number (string->number str)))
(and number (max 20 (- number 1))))))
(define (guix-substitute . args)
"Implement the build daemon's substituter protocol."
(mkdir-p %narinfo-cache-directory)
;; Starting from commit 22144afa in Nix, we are allowed to bail out directly
;; when we know we cannot substitute, but we must emit a newline on stdout
;; when everything is alright.
(when (null? %cache-urls)
(exit 0))
;; Say hello (see above.)
(force-output (current-output-port))
;; Attempt to install the client's locale, mostly so that messages are
;; suitably translated.
(match (or (find-daemon-option "untrusted-locale")
(find-daemon-option "locale"))
(#f #f)
(locale (false-if-exception (setlocale LC_ALL locale))))
(with-error-handling ; for signature errors
(match args
(let ((acl (current-acl)))
(let loop ((command (read-line)))
(or (eof-object? command)
(process-query command
#:cache-urls %cache-urls
#:acl acl)
(loop (read-line)))))))
(("--substitute" store-path destination)
;; Download STORE-PATH and add store it as a Nar in file DESTINATION.
;; Specify the number of columns of the terminal so the progress
;; report displays nicely.
(parameterize ((current-terminal-columns (client-terminal-columns)))
(process-substitution store-path destination
#:cache-urls %cache-urls
#:acl (current-acl))))
(show-version-and-exit "guix substitute"))
(leave (_ "~a: unrecognized options~%") opts))))))
;;; Local Variables:
;;; eval: (put 'with-timeout 'scheme-indent-function 1)
;;; End:
;;; substitute.scm ends here