guix-devel/guix/scripts/publish.scm

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;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2015 David Thompson <davet@gnu.org>
;;; Copyright © 2015, 2016 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 publish)
#:use-module ((system repl server) #:prefix repl:)
#:use-module (ice-9 binary-ports)
#:use-module (ice-9 format)
#:use-module (ice-9 match)
#:use-module (ice-9 regex)
#:use-module (rnrs io ports)
#:use-module (rnrs bytevectors)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-2)
#:use-module (srfi srfi-9 gnu)
#:use-module (srfi srfi-26)
#:use-module (srfi srfi-37)
#:use-module (web http)
#:use-module (web request)
#:use-module (web response)
#:use-module (web server)
#:use-module (web uri)
#:use-module (guix base32)
#:use-module (guix base64)
#:use-module (guix config)
#:use-module (guix derivations)
#:use-module (guix hash)
#:use-module (guix pki)
#:use-module (guix pk-crypto)
#:use-module (guix store)
#:use-module (guix serialization)
#:use-module (guix ui)
#:use-module (guix scripts)
#:export (guix-publish))
(define (show-help)
(format #t (_ "Usage: guix publish [OPTION]...
Publish ~a over HTTP.\n") %store-directory)
(display (_ "
-p, --port=PORT listen on PORT"))
(display (_ "
--listen=HOST listen on the network interface for HOST"))
(display (_ "
-u, --user=USER change privileges to USER as soon as possible"))
(display (_ "
-r, --repl[=PORT] spawn REPL server on PORT"))
(newline)
(display (_ "
-h, --help display this help and exit"))
(display (_ "
-V, --version display version information and exit"))
(newline)
(show-bug-report-information))
(define (getaddrinfo* host)
"Like 'getaddrinfo', but properly report errors."
(catch 'getaddrinfo-error
(lambda ()
(getaddrinfo host))
(lambda (key error)
(leave (_ "lookup of host '~a' failed: ~a~%")
host (gai-strerror error)))))
(define %options
(list (option '(#\h "help") #f #f
(lambda _
(show-help)
(exit 0)))
(option '(#\V "version") #f #f
(lambda _
(show-version-and-exit "guix publish")))
(option '(#\u "user") #t #f
(lambda (opt name arg result)
(alist-cons 'user arg result)))
(option '(#\p "port") #t #f
(lambda (opt name arg result)
(alist-cons 'port (string->number* arg) result)))
(option '("listen") #t #f
(lambda (opt name arg result)
(match (getaddrinfo* arg)
((info _ ...)
(alist-cons 'address (addrinfo:addr info)
result))
(()
(leave (_ "lookup of host '~a' returned nothing")
name)))))
(option '(#\r "repl") #f #t
(lambda (opt name arg result)
;; If port unspecified, use default Guile REPL port.
(let ((port (and arg (string->number* arg))))
(alist-cons 'repl (or port 37146) result))))))
(define %default-options
`((port . 8080)
(address . ,(make-socket-address AF_INET INADDR_ANY 0))
(repl . #f)))
(define (lazy-read-file-sexp file)
"Return a promise to read the canonical sexp from FILE."
(delay
(call-with-input-file file
(compose string->canonical-sexp
get-string-all))))
(define %private-key
(lazy-read-file-sexp %private-key-file))
(define %public-key
(lazy-read-file-sexp %public-key-file))
(define %nix-cache-info
`(("StoreDir" . ,%store-directory)
("WantMassQuery" . 0)
("Priority" . 100)))
(define (load-derivation file)
"Read the derivation from FILE."
(call-with-input-file file read-derivation))
(define (signed-string s)
"Sign the hash of the string S with the daemon's key."
(let* ((public-key (force %public-key))
(hash (bytevector->hash-data (sha256 (string->utf8 s))
#:key-type (key-type public-key))))
(signature-sexp hash (force %private-key) public-key)))
(define base64-encode-string
(compose base64-encode string->utf8))
(define (narinfo-string store store-path key)
"Generate a narinfo key/value string for STORE-PATH; an exception is raised
if STORE-PATH is invalid. The narinfo is signed with KEY."
(let* ((path-info (query-path-info store store-path))
(url (string-append "nar/" (basename store-path)))
(hash (bytevector->nix-base32-string
(path-info-hash path-info)))
(size (path-info-nar-size path-info))
(references (string-join
(map basename (path-info-references path-info))
" "))
(deriver (path-info-deriver path-info))
(base-info (format #f
"StorePath: ~a
URL: ~a
Compression: none
NarHash: sha256:~a
NarSize: ~d
References: ~a~%"
store-path url hash size references))
;; Do not render a "Deriver" or "System" line if we are rendering
;; info for a derivation.
(info (if (string-null? deriver)
base-info
(catch 'system-error
(lambda ()
(let ((drv (load-derivation deriver)))
(format #f "~aSystem: ~a~%Deriver: ~a~%"
base-info (derivation-system drv)
(basename deriver))))
(lambda args
;; DERIVER might be missing, but that's fine:
;; it's only used for <substitutable> where it's
;; optional. 'System' is currently unused.
(if (= ENOENT (system-error-errno args))
base-info
(apply throw args))))))
(signature (base64-encode-string
(canonical-sexp->string (signed-string info)))))
(format #f "~aSignature: 1;~a;~a~%" info (gethostname) signature)))
(define (not-found request)
"Render 404 response for REQUEST."
(values (build-response #:code 404)
(string-append "Resource not found: "
(uri-path (request-uri request)))))
(define (render-nix-cache-info)
"Render server information."
(values '((content-type . (text/plain)))
(lambda (port)
(for-each (match-lambda
((key . value)
(format port "~a: ~a~%" key value)))
%nix-cache-info))))
(define (render-narinfo store request hash)
"Render metadata for the store path corresponding to HASH."
(let ((store-path (hash-part->path store hash)))
(if (string-null? store-path)
(not-found request)
(values '((content-type . (application/x-nix-narinfo)))
(cut display
(narinfo-string store store-path (force %private-key))
<>)))))
(define (render-nar request store-item)
"Render archive of the store path corresponding to STORE-ITEM."
(let ((store-path (string-append %store-directory "/" store-item)))
;; The ISO-8859-1 charset *must* be used otherwise HTTP clients will
;; interpret the byte stream as UTF-8 and arbitrarily change invalid byte
;; sequences.
(if (file-exists? store-path)
(values '((content-type . (application/x-nix-archive
(charset . "ISO-8859-1"))))
;; XXX: We're not returning the actual contents, deferring
;; instead to 'http-write'. This is a hack to work around
;; <http://bugs.gnu.org/21093>.
store-path)
(not-found request))))
(define extract-narinfo-hash
(let ((regexp (make-regexp "^([a-df-np-sv-z0-9]{32}).narinfo$")))
(lambda (str)
"Return the hash within the narinfo resource string STR, or false if STR
is invalid."
(and=> (regexp-exec regexp str)
(cut match:substring <> 1)))))
(define (get-request? request)
"Return #t if REQUEST uses the GET method."
(eq? (request-method request) 'GET))
(define (request-path-components request)
"Split the URI path of REQUEST into a list of component strings. For
example: \"/foo/bar\" yields '(\"foo\" \"bar\")."
(split-and-decode-uri-path (uri-path (request-uri request))))
;;;
;;; Server.
;;;
(define %http-write
(@@ (web server http) http-write))
(define (sans-content-length response)
"Return RESPONSE without its 'content-length' header."
(set-field response (response-headers)
(alist-delete 'content-length
(response-headers response)
eq?)))
(define-syntax-rule (swallow-EPIPE exp ...)
"Swallow EPIPE errors raised by EXP..."
(catch 'system-error
(lambda ()
exp ...)
(lambda args
(if (= EPIPE (system-error-errno args))
(values)
(apply throw args)))))
(define (http-write server client response body)
"Write RESPONSE and BODY to CLIENT, possibly in a separate thread to avoid
blocking."
(match (response-content-type response)
(('application/x-nix-archive . _)
;; Sending the the whole archive can take time so do it in a separate
;; thread so that the main thread can keep working in the meantime.
(call-with-new-thread
(lambda ()
(let* ((response (write-response (sans-content-length response)
client))
(port (response-port response)))
;; XXX: Given our ugly workaround for <http://bugs.gnu.org/21093> in
;; 'render-nar', BODY here is just the file name of the store item.
;; We call 'write-file' from here because we know that's the only
;; way to avoid building the whole nar in memory, which could
;; quickly become a real problem. As a bonus, we even do
;; sendfile(2) directly from the store files to the socket.
(swallow-EPIPE
(write-file (utf8->string body) port))
(close-port port)
(values)))))
(_
;; Handle other responses sequentially.
(%http-write server client response body))))
(define-server-impl concurrent-http-server
;; A variant of Guile's built-in HTTP server that offloads possibly long
;; responses to a different thread.
(@@ (web server http) http-open)
(@@ (web server http) http-read)
http-write
(@@ (web server http) http-close))
(define (make-request-handler store)
(lambda (request body)
(format #t "~a ~a~%"
(request-method request)
(uri-path (request-uri request)))
(if (get-request? request) ; reject POST, PUT, etc.
(match (request-path-components request)
;; /nix-cache-info
(("nix-cache-info")
(render-nix-cache-info))
;; /<hash>.narinfo
(((= extract-narinfo-hash (? string? hash)))
(render-narinfo store request hash))
;; /nar/<store-item>
(("nar" store-item)
(render-nar request store-item))
(_ (not-found request)))
(not-found request))))
(define (run-publish-server socket store)
(run-server (make-request-handler store)
concurrent-http-server
`(#:socket ,socket)))
(define (open-server-socket address)
"Return a TCP socket bound to ADDRESS, a socket address."
(let ((sock (socket (sockaddr:fam address) SOCK_STREAM 0)))
(setsockopt sock SOL_SOCKET SO_REUSEADDR 1)
(bind sock address)
sock))
(define (gather-user-privileges user)
"Switch to the identity of USER, a user name."
(catch 'misc-error
(lambda ()
(let ((user (getpw user)))
(setgroups #())
(setgid (passwd:gid user))
(setuid (passwd:uid user))))
(lambda (key proc message args . rest)
(leave (_ "user '~a' not found: ~a~%")
user (apply format #f message args)))))
;;;
;;; Entry point.
;;;
(define (guix-publish . args)
(with-error-handling
(let* ((opts (args-fold* args %options
(lambda (opt name arg result)
(leave (_ "~A: unrecognized option~%") name))
(lambda (arg result)
(leave (_ "~A: extraneous argument~%") arg))
%default-options))
(user (assoc-ref opts 'user))
(port (assoc-ref opts 'port))
(address (let ((addr (assoc-ref opts 'address)))
(make-socket-address (sockaddr:fam addr)
(sockaddr:addr addr)
port)))
(socket (open-server-socket address))
(repl-port (assoc-ref opts 'repl)))
;; Read the key right away so that (1) we fail early on if we can't
;; access them, and (2) we can then drop privileges.
(force %private-key)
(force %public-key)
(when user
;; Now that we've read the key material and opened the socket, we can
;; drop privileges.
(gather-user-privileges user))
(when (zero? (getuid))
(warning (_ "server running as root; \
consider using the '--user' option!~%")))
(format #t (_ "publishing ~a on ~a, port ~d~%")
%store-directory
(inet-ntop (sockaddr:fam address) (sockaddr:addr address))
(sockaddr:port address))
(when repl-port
(repl:spawn-server (repl:make-tcp-server-socket #:port repl-port)))
(with-store store
(run-publish-server socket store)))))