guix-devel/guix/scripts/substitute.scm

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;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2013, 2014, 2015 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
;;; 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)
#:use-module (guix ui)
#:use-module (guix store)
#:use-module (guix utils)
#:use-module (guix config)
#:use-module (guix records)
#:use-module (guix serialization)
#:use-module (guix hash)
#: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 (progress-proc uri-abbreviation))
#: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 request)
#:use-module (web response)
#:use-module (guix http-client)
#:export (narinfo-signature->canonical-sexp
read-narinfo
write-narinfo
guix-substitute))
;;; 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.
(or (and=> (getenv "XDG_CACHE_HOME")
(cut string-append <> "/guix/substitute"))
(string-append %state-directory "/substitute/cache")))
(define %allow-unauthenticated-substitutes?
;; Whether to allow unchecked substitutes. This is useful for testing
;; purposes, and should be avoided otherwise.
(and (and=> (getenv "GUIX_ALLOW_UNAUTHENTICATED_SUBSTITUTES")
(cut string-ci=? <> "yes"))
(begin
(warning (_ "authentication and authorization of substitutes \
disabled!~%"))
#t)))
(define %narinfo-ttl
;; Number of seconds during which cached narinfo lookups are considered
;; valid. This is a reasonable default value (corresponds to the TTL for
;; nginx's .nar cache on hydra.gnu.org) but we'd rather want publishers to
;; state what their TTL is in /nix-cache-info. (XXX)
(* 36 3600))
(define %narinfo-negative-ttl
;; Likewise, but for negative lookups---i.e., cached lookup failures.
(* 3 3600))
(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.
recutils->alist)
(define %fetch-timeout
;; Number of seconds after which networking is considered "slow".
5)
(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
again."
(begin
(sigaction SIGALRM
(lambda (signum)
(sigaction SIGALRM SIG_DFL)
handler))
(alarm duration)
(call-with-values
(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))
(begin
;; Wait a little to avoid bursts.
(usleep (random 3000000 %random-state))
(try))
(apply throw args))))))
(lambda result
(alarm 0)
(sigaction SIGALRM SIG_DFL)
(apply values result)))))
(define* (fetch uri #:key (buffered? #t) (timeout? #t) (quiet-404? #f))
"Return a binary input port to URI and the number of bytes it's expected to
provide. If QUIET-404? is true, HTTP 404 error conditions are passed through
to the caller without emitting an error message."
(case (uri-scheme uri)
((file)
(let ((port (open-file (uri-path uri)
(if buffered? "rb" "r0b"))))
(values port (stat:size (stat port)))))
((http)
(guard (c ((http-get-error? c)
(let ((code (http-get-error-code c)))
(if (and (= code 404) quiet-404?)
(raise c)
(leave (_ "download from '~a' failed: ~a, ~s~%")
(uri->string (http-get-error-uri c))
code (http-get-error-reason c))))))
;; On Guile 2.0.5, `http-fetch' fetches the whole thing at once. So
;; honor TIMEOUT? to disable the timeout when fetching a nar.
;;
;; 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 (or timeout? (guile-version>? "2.0.5"))
%fetch-timeout
0)
(begin
(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) "2.0.9.39"))
(when port
(close-port port))))
(begin
(when (or (not port) (port-closed? port))
(set! port (open-socket-for-uri uri))
(unless buffered?
(setvbuf port _IONBF)))
(http-fetch uri #:text? #f #:port port))))))))
(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-syntax-rule (open-cache* url)
"Delayed variant of 'open-cache' that also lets the user know that they're
gonna have to wait."
(delay (begin
(format (current-error-port)
(_ "updating list of substitutes from '~a'...\r")
url)
(open-cache url))))
(define-record-type <narinfo>
(%make-narinfo path uri uri-base compression file-hash file-size nar-hash nar-size
references deriver system signature contents)
narinfo?
(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-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~%")
version))
;; Currently, there are no other versions.
((not (= 1 maybe-number))
(leave (_ "unsupported signature version: ~a~%")
maybe-number))
(else
(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~%")
signature))))))))
(x
(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)))
cache-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
(false-if-exception
(and=> signature narinfo-signature->canonical-sexp))
str)))
(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)
(invalid-signature
(leave (_ "invalid signature for '~a'~%") uri))
(hash-mismatch
(leave (_ "hash mismatch for '~a'~%") uri))
(unauthorized-key
(leave (_ "'~a' is signed with an unauthorized key~%") uri))
(corrupt-signature
(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"
"Signature"))))
(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)
(index
(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?
narinfo
(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?
(format (current-error-port)
"found valid signature for '~a', from '~a'~%"
(narinfo-path narinfo)
(uri->string (narinfo-uri narinfo)))))
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 path)
"Return the name of the local file that contains an entry for PATH."
(string-append %narinfo-cache-directory "/"
(store-path-hash-part path)))
(define (cached-narinfo path)
"Check locally if we have valid info about PATH. 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 path))
(catch 'system-error
(lambda ()
(call-with-input-file cache-file
(lambda (p)
(match (read p)
(('narinfo ('version 1)
('cache-uri cache-uri)
('date date) ('value #f))
;; A cached negative lookup.
(if (obsolete? date now %narinfo-negative-ttl)
(values #f #f)
(values #t #f)))
(('narinfo ('version 1)
('cache-uri cache-uri)
('date date) ('value value))
;; A cached positive lookup
(if (obsolete? date now %narinfo-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 path narinfo)
"Cache locally NARNIFO for PATH, which originates from CACHE. NARINFO may
be #f, in which case it indicates that PATH is unavailable at CACHE."
(define now
(current-time time-monotonic))
(define (cache-entry cache-uri narinfo)
`(narinfo (version 1)
(cache-uri ,cache-uri)
(date ,(time-second now))
(value ,(and=> narinfo narinfo->string))))
(with-atomic-file-output (narinfo-cache-file path)
(lambda (out)
(write (cache-entry (cache-url cache) narinfo) out)))
narinfo)
(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)
".narinfo")))
(build-request (string->uri url) #:method 'GET)))
(define (http-multiple-get base-url requests proc)
"Send all of REQUESTS to the server at BASE-URL. Call PROC for each
response, passing it the request object, the response, and a port from which
to read the response body. Return the list of results."
(let connect ((requests requests)
(result '()))
;; (format (current-error-port) "connecting (~a requests left)..."
;; (length requests))
(let ((p (open-socket-for-uri base-url)))
;; Send all of REQUESTS in a row.
(setvbuf p _IOFBF (expt 2 16))
(for-each (cut write-request <> p) requests)
(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)))
;; The server can choose to stop responding at any time, in which
;; case we have to try again. Check whether that is the case.
(match (assq 'connection (response-headers resp))
(('connection 'close)
(close-port p)
(connect requests result)) ;try again
(_
(loop tail ;keep going
(cons (proc head resp body) result)))))))))))
(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))
#f
(apply throw args)))))
(define (fetch-narinfos cache paths)
"Retrieve all the narinfos for PATHS from CACHE and return them."
(define url
(cache-url cache))
(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)
(let ((len (response-content-length response)))
;; Make sure to read no more than LEN bytes since subsequent bytes may
;; belong to the next response.
(case (response-code response)
((200) ; hit
(let ((narinfo (read-narinfo port url #:size len)))
(cache-narinfo! cache (narinfo-path narinfo) narinfo)
(update-progress!)
narinfo))
((404) ; failure
(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! cache
(find (cut string-contains <> hash-part) paths)
#f)
(update-progress!))
#f)
(else ; transient failure
(if len
(get-bytevector-n port len)
(read-to-eof port))
#f))))
(and (string=? (cache-store-directory cache) (%store-prefix))
(let ((uri (string->uri url)))
(case (and=> uri uri-scheme)
((http)
(let ((requests (map (cut narinfo-request url <>) paths)))
(update-progress!)
(let ((result (http-multiple-get url requests
handle-narinfo-response)))
(newline (current-error-port))
result)))
((file #f)
(let* ((base (string-append (uri-path uri) "/"))
(files (map (compose (cut string-append base <> ".narinfo")
store-path-hash-part)
paths)))
(filter-map (cut narinfo-from-file <> url) files)))
(else
(leave (_ "~s: unsupported server URI scheme~%")
(if uri (uri-scheme uri) url)))))))
(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 path)))
(if valid?
(values (cons value cached) missing)
(values cached (cons path missing)))))
'()
'()
paths)))
(if (null? missing)
cached
(let* ((cache (force cache))
(missing (if cache
(fetch-narinfos cache missing)
'())))
(append cached missing)))))
(define (lookup-narinfo cache path)
"Return the narinfo for PATH in CACHE, or #f when no substitute for PATH was
found."
(match (lookup-narinfos cache (list path))
((answer) answer)))
(define (remove-expired-cached-narinfos)
"Remove expired narinfo entries from the cache. The sole purpose of this
function is to make sure `%narinfo-cache-directory' doesn't grow
indefinitely."
(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 1) ('cache-uri _) ('date date)
('value #f))
(obsolete? date now %narinfo-negative-ttl))
(('narinfo ('version 1) ('cache-uri _) ('date date)
('value _))
(obsolete? date now %narinfo-ttl))
(_ #t)))))
(lambda args
;; FILE may have been deleted.
#t)))
(for-each (lambda (file)
(let ((file (string-append %narinfo-cache-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 %narinfo-cache-directory
(lambda (file)
(= (string-length file) 32)))))
(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))
0))
(when (obsolete? last-expiry-date now %narinfo-expired-cache-entry-removal-delay)
(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
`progress-proc'."
(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.
n))
;; Since `http-fetch' in Guile 2.0.5 returns all the data once it's done,
;; don't pretend to report any progress in that case.
(if (guile-version>? "2.0.5")
(make-custom-binary-input-port "progress-port-proc"
read! #f #f
(cut close-port port))
(begin
(format (current-error-port) (_ "Downloading, please wait...~%"))
(format (current-error-port)
(_ "(Please consider upgrading Guile to get proper progress report.)~%"))
port)))
(define-syntax with-networking
(syntax-rules ()
"Catch DNS lookup 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 'getaddrinfo-error
(lambda () exp ...)
(lambda (key error)
(leave (_ "host name lookup error: ~a~%")
(gai-strerror error)))))))
;;;
;;; 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 (_ "
--substitute STORE-FILE DESTINATION
download STORE-FILE and store it as a Nar in file
DESTINATION"))
(newline)
(display (_ "
-h, --help display this help and exit"))
(display (_ "
-V, --version display version information and exit"))
(newline)
(show-bug-report-information))
;;;
;;; 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
get-string-all))))
(match acl
((thing)
(equal? (canonical-sexp->string thing)
(canonical-sexp->string key)))
(_
#f)))))
(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
'())
(newline-separated
;; 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
#f)
(equal-sign
(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
found."
(assoc-ref (daemon-options) option))
(define %cache-url
(match (and=> ;; TODO: Uncomment the following lines when multiple
;; substitute sources are supported.
;; (find-daemon-option "untrusted-substitute-urls") ;client
;; " "
(find-daemon-option "substitute-urls") ;admin
string-tokenize)
((url)
url)
((head tail ..1)
;; Currently we don't handle multiple substitute URLs.
(warning (_ "these substitute URLs will not be used:~{ ~a~}~%")
tail)
head)
(#f
;; This can only happen when this script is not invoked by the
;; daemon.
"http://hydra.gnu.org")))
(define (guix-substitute . args)
"Implement the build daemon's substituter protocol."
(mkdir-p %narinfo-cache-directory)
(maybe-remove-expired-cached-narinfo)
(check-acl-initialized)
;; 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.
(let ((uri (string->uri %cache-url)))
(case (uri-scheme uri)
((http)
;; Exit gracefully if there's no network access.
(let ((host (uri-host uri)))
(catch 'getaddrinfo-error
(lambda ()
(getaddrinfo host))
(lambda (key error)
(warning (_ "failed to look up host '~a' (~a), \
substituter disabled~%")
host (gai-strerror error))
(exit 0)))))
(else #t)))
;; Say hello (see above.)
(newline)
(force-output (current-output-port))
(with-networking
(with-error-handling ; for signature errors
(match args
(("--query")
(let ((cache (open-cache* %cache-url))
(acl (current-acl)))
(define (valid? obj)
(and (narinfo? obj) (valid-narinfo? obj acl)))
(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
(lookup-narinfos cache paths)
'())))
(for-each (lambda (narinfo)
(format #t "~a~%" (narinfo-path narinfo)))
(filter valid? substitutable))
(newline)))
(("info" paths ..1)
;; Reply info about PATHS if it's in CACHE.
(let ((substitutable
(if cache
(lookup-narinfos 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 valid? 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 (lookup-narinfo cache store-path))
(uri (narinfo-uri narinfo)))
;; Make sure it is signed and everything.
(assert-valid-narinfo narinfo)
;; Tell the daemon what the expected hash of the Nar itself is.
(format #t "~a~%" (narinfo-hash narinfo))
(format (current-error-port) "downloading `~a'~:[~*~; (~,1f MiB installed)~]...~%"
store-path
;; Use the Nar size as an estimate of the installed size.
(narinfo-size narinfo)
(and=> (narinfo-size narinfo)
(cute / <> (expt 2. 20))))
(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))
((progress)
(let* ((comp (narinfo-compression narinfo))
(dl-size (or download-size
(and (equal? comp "none")
(narinfo-size narinfo))))
(progress (progress-proc (uri-abbreviation uri)
dl-size
(current-error-port))))
(progress-report-port progress raw)))
((input pids)
(decompressed-port (and=> (narinfo-compression narinfo)
string->symbol)
progress)))
;; 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))))
(("--version")
(show-version-and-exit "guix substitute"))
(("--help")
(show-help))
(opts
(leave (_ "~a: unrecognized options~%") opts))))))
;;; Local Variables:
;;; eval: (put 'with-timeout 'scheme-indent-function 1)
;;; End:
;;; substitute.scm ends here