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987a29ba | 1 | ;;; GNU Guix --- Functional package management for GNU |
d06d54e3 | 2 | ;;; Copyright © 2016, 2017, 2018 Ludovic Courtès <ludo@gnu.org> |
987a29ba LC |
3 | ;;; |
4 | ;;; This file is part of GNU Guix. | |
5 | ;;; | |
6 | ;;; GNU Guix is free software; you can redistribute it and/or modify it | |
7 | ;;; under the terms of the GNU General Public License as published by | |
8 | ;;; the Free Software Foundation; either version 3 of the License, or (at | |
9 | ;;; your option) any later version. | |
10 | ;;; | |
11 | ;;; GNU Guix is distributed in the hope that it will be useful, but | |
12 | ;;; WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | ;;; GNU General Public License for more details. | |
15 | ;;; | |
16 | ;;; You should have received a copy of the GNU General Public License | |
17 | ;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>. | |
18 | ||
19 | (define-module (guix ssh) | |
20 | #:use-module (guix store) | |
52d174d6 | 21 | #:use-module (guix i18n) |
896fec47 | 22 | #:use-module ((guix utils) #:select (&fix-hint)) |
615c5298 LC |
23 | #:use-module (ssh session) |
24 | #:use-module (ssh auth) | |
25 | #:use-module (ssh key) | |
987a29ba LC |
26 | #:use-module (ssh channel) |
27 | #:use-module (ssh popen) | |
28 | #:use-module (ssh session) | |
29 | #:use-module (ssh dist) | |
30 | #:use-module (ssh dist node) | |
0e3c8528 | 31 | #:use-module (srfi srfi-1) |
987a29ba | 32 | #:use-module (srfi srfi-11) |
d06d54e3 | 33 | #:use-module (srfi srfi-26) |
13164a21 LC |
34 | #:use-module (srfi srfi-34) |
35 | #:use-module (srfi srfi-35) | |
987a29ba | 36 | #:use-module (ice-9 match) |
13164a21 | 37 | #:use-module (ice-9 binary-ports) |
615c5298 | 38 | #:export (open-ssh-session |
e5378337 | 39 | remote-daemon-channel |
615c5298 | 40 | connect-to-remote-daemon |
987a29ba LC |
41 | send-files |
42 | retrieve-files | |
d06d54e3 | 43 | retrieve-files* |
4eb0f9ae LC |
44 | remote-store-host |
45 | ||
46 | report-guile-error | |
47 | report-module-error)) | |
987a29ba LC |
48 | |
49 | ;;; Commentary: | |
50 | ;;; | |
51 | ;;; This module provides tools to support communication with remote stores | |
52 | ;;; over SSH, using Guile-SSH. | |
53 | ;;; | |
54 | ;;; Code: | |
55 | ||
615c5298 LC |
56 | (define %compression |
57 | "zlib@openssh.com,zlib") | |
58 | ||
59 | (define* (open-ssh-session host #:key user port | |
60 | (compression %compression)) | |
61 | "Open an SSH session for HOST and return it. When USER and PORT are #f, use | |
62 | default values or whatever '~/.ssh/config' specifies; otherwise use them. | |
63 | Throw an error on failure." | |
64 | (let ((session (make-session #:user user | |
65 | #:host host | |
66 | #:port port | |
67 | #:timeout 10 ;seconds | |
68 | ;; #:log-verbosity 'protocol | |
69 | ||
70 | ;; We need lightweight compression when | |
71 | ;; exchanging full archives. | |
72 | #:compression compression | |
73 | #:compression-level 3))) | |
74 | ||
75 | ;; Honor ~/.ssh/config. | |
76 | (session-parse-config! session) | |
77 | ||
78 | (match (connect! session) | |
79 | ('ok | |
80 | ;; Use public key authentication, via the SSH agent if it's available. | |
81 | (match (userauth-public-key/auto! session) | |
82 | ('success | |
83 | session) | |
84 | (x | |
85 | (disconnect! session) | |
86 | (raise (condition | |
87 | (&message | |
69daee23 | 88 | (message (format #f (G_ "SSH authentication failed for '~a': ~a~%") |
615c5298 LC |
89 | host (get-error session))))))))) |
90 | (x | |
91 | ;; Connection failed or timeout expired. | |
92 | (raise (condition | |
93 | (&message | |
69daee23 | 94 | (message (format #f (G_ "SSH connection to '~a' failed: ~a~%") |
615c5298 LC |
95 | host (get-error session)))))))))) |
96 | ||
e5378337 LC |
97 | (define* (remote-daemon-channel session |
98 | #:optional | |
99 | (socket-name | |
100 | "/var/guix/daemon-socket/socket")) | |
101 | "Return an input/output port (an SSH channel) to the daemon at SESSION." | |
987a29ba LC |
102 | (define redirect |
103 | ;; Code run in SESSION to redirect the remote process' stdin/stdout to the | |
104 | ;; daemon's socket, à la socat. The SSH protocol supports forwarding to | |
105 | ;; Unix-domain sockets but libssh doesn't have an API for that, hence this | |
106 | ;; hack. | |
107 | `(begin | |
17af5d51 | 108 | (use-modules (ice-9 match) (rnrs io ports) |
0dcf675c | 109 | (rnrs bytevectors)) |
987a29ba | 110 | |
8446dc5a LC |
111 | (let ((sock (socket AF_UNIX SOCK_STREAM 0)) |
112 | (stdin (current-input-port)) | |
113 | (stdout (current-output-port)) | |
114 | (select* (lambda (read write except) | |
115 | ;; This is a workaround for | |
116 | ;; <https://bugs.gnu.org/30365> in Guile < 2.2.4: | |
117 | ;; since 'select' sometimes returns non-empty sets for | |
118 | ;; no good reason, call 'select' a second time with a | |
119 | ;; zero timeout to filter out incorrect replies. | |
120 | (match (select read write except) | |
121 | ((read write except) | |
122 | (select read write except 0)))))) | |
987a29ba | 123 | (setvbuf stdout _IONBF) |
0dcf675c LC |
124 | |
125 | ;; Use buffered ports so that 'get-bytevector-some' returns up to the | |
126 | ;; whole buffer like read(2) would--see <https://bugs.gnu.org/30066>. | |
127 | (setvbuf stdin _IOFBF 65536) | |
128 | (setvbuf sock _IOFBF 65536) | |
129 | ||
987a29ba LC |
130 | (connect sock AF_UNIX ,socket-name) |
131 | ||
132 | (let loop () | |
8446dc5a | 133 | (match (select* (list stdin sock) '() '()) |
55f40fdb | 134 | ((reads () ()) |
987a29ba | 135 | (when (memq stdin reads) |
0dcf675c LC |
136 | (match (get-bytevector-some stdin) |
137 | ((? eof-object?) | |
987a29ba | 138 | (primitive-exit 0)) |
0dcf675c LC |
139 | (bv |
140 | (put-bytevector sock bv) | |
141 | (force-output sock)))) | |
987a29ba | 142 | (when (memq sock reads) |
0dcf675c LC |
143 | (match (get-bytevector-some sock) |
144 | ((? eof-object?) | |
987a29ba | 145 | (primitive-exit 0)) |
0dcf675c LC |
146 | (bv |
147 | (put-bytevector stdout bv)))) | |
987a29ba LC |
148 | (loop)) |
149 | (_ | |
150 | (primitive-exit 1))))))) | |
151 | ||
e5378337 LC |
152 | (open-remote-pipe* session OPEN_BOTH |
153 | ;; Sort-of shell-quote REDIRECT. | |
154 | "guile" "-c" | |
155 | (object->string | |
156 | (object->string redirect)))) | |
157 | ||
158 | (define* (connect-to-remote-daemon session | |
159 | #:optional | |
160 | (socket-name | |
161 | "/var/guix/daemon-socket/socket")) | |
162 | "Connect to the remote build daemon listening on SOCKET-NAME over SESSION, | |
163 | an SSH session. Return a <nix-server> object." | |
164 | (open-connection #:port (remote-daemon-channel session))) | |
165 | ||
987a29ba LC |
166 | |
167 | (define (store-import-channel session) | |
168 | "Return an output port to which archives to be exported to SESSION's store | |
169 | can be written." | |
170 | ;; Using the 'import-paths' RPC on a remote store would be slow because it | |
171 | ;; makes a round trip every time 32 KiB have been transferred. This | |
172 | ;; procedure instead opens a separate channel to use the remote | |
173 | ;; 'import-paths' procedure, which consumes all the data in a single round | |
de9d8f0e LC |
174 | ;; trip. This optimizes the successful case at the expense of error |
175 | ;; conditions: errors can only be reported once all the input has been | |
176 | ;; consumed. | |
987a29ba LC |
177 | (define import |
178 | `(begin | |
de9d8f0e LC |
179 | (use-modules (guix) (srfi srfi-34) |
180 | (rnrs io ports) (rnrs bytevectors)) | |
987a29ba | 181 | |
de9d8f0e LC |
182 | (define (consume-input port) |
183 | (let ((bv (make-bytevector 32768))) | |
184 | (let loop () | |
185 | (let ((n (get-bytevector-n! port bv 0 | |
186 | (bytevector-length bv)))) | |
187 | (unless (eof-object? n) | |
188 | (loop)))))) | |
987a29ba | 189 | |
de9d8f0e LC |
190 | ;; Upon completion, write an sexp that denotes the status. |
191 | (write | |
192 | (catch #t | |
193 | (lambda () | |
194 | (guard (c ((nix-protocol-error? c) | |
195 | ;; Consume all the input since the only time we can | |
196 | ;; report the error is after everything has been | |
197 | ;; consumed. | |
198 | (consume-input (current-input-port)) | |
199 | (list 'protocol-error (nix-protocol-error-message c)))) | |
200 | (with-store store | |
201 | (setvbuf (current-input-port) _IONBF) | |
202 | (import-paths store (current-input-port)) | |
203 | '(success)))) | |
204 | (lambda args | |
205 | (cons 'error args)))))) | |
987a29ba | 206 | |
de9d8f0e LC |
207 | (open-remote-pipe session |
208 | (string-join | |
209 | `("guile" "-c" | |
210 | ,(object->string (object->string import)))) | |
211 | OPEN_BOTH)) | |
987a29ba | 212 | |
e9629e82 LC |
213 | (define* (store-export-channel session files |
214 | #:key recursive?) | |
987a29ba | 215 | "Return an input port from which an export of FILES from SESSION's store can |
e9629e82 | 216 | be read. When RECURSIVE? is true, the closure of FILES is exported." |
987a29ba LC |
217 | ;; Same as above: this is more efficient than calling 'export-paths' on a |
218 | ;; remote store. | |
219 | (define export | |
220 | `(begin | |
896fec47 LC |
221 | (eval-when (load expand eval) |
222 | (unless (resolve-module '(guix) #:ensure #f) | |
223 | (write `(module-error)) | |
224 | (exit 7))) | |
225 | ||
226 | (use-modules (guix) (srfi srfi-1) | |
227 | (srfi srfi-26) (srfi srfi-34)) | |
228 | ||
229 | (guard (c ((nix-connection-error? c) | |
230 | (write `(connection-error ,(nix-connection-error-file c) | |
231 | ,(nix-connection-error-code c)))) | |
232 | ((nix-protocol-error? c) | |
233 | (write `(protocol-error ,(nix-protocol-error-status c) | |
234 | ,(nix-protocol-error-message c)))) | |
235 | (else | |
236 | (write `(exception)))) | |
237 | (with-store store | |
238 | (let* ((files ',files) | |
239 | (invalid (remove (cut valid-path? store <>) | |
240 | files))) | |
241 | (unless (null? invalid) | |
242 | (write `(invalid-items ,invalid)) | |
243 | (exit 1)) | |
244 | ||
0e3c8528 LC |
245 | ;; TODO: When RECURSIVE? is true, we could send the list of store |
246 | ;; items in the closure so that the other end can filter out | |
247 | ;; those it already has. | |
248 | ||
896fec47 LC |
249 | (write '(exporting)) ;we're ready |
250 | (force-output) | |
251 | ||
252 | (setvbuf (current-output-port) _IONBF) | |
253 | (export-paths store files (current-output-port) | |
254 | #:recursive? ,recursive?)))))) | |
987a29ba LC |
255 | |
256 | (open-remote-input-pipe session | |
257 | (string-join | |
258 | `("guile" "-c" | |
259 | ,(object->string | |
260 | (object->string export)))))) | |
261 | ||
262 | (define* (send-files local files remote | |
e9629e82 LC |
263 | #:key |
264 | recursive? | |
265 | (log-port (current-error-port))) | |
987a29ba | 266 | "Send the subset of FILES from LOCAL (a local store) that's missing to |
23973e4f LC |
267 | REMOTE, a remote store. When RECURSIVE? is true, send the closure of FILES. |
268 | Return the list of store items actually sent." | |
987a29ba | 269 | ;; Compute the subset of FILES missing on SESSION and send them. |
e9629e82 LC |
270 | (let* ((files (if recursive? (requisites local files) files)) |
271 | (session (channel-get-session (nix-server-socket remote))) | |
987a29ba LC |
272 | (node (make-node session)) |
273 | (missing (node-eval node | |
274 | `(begin | |
275 | (use-modules (guix) | |
276 | (srfi srfi-1) (srfi srfi-26)) | |
277 | ||
278 | (with-store store | |
279 | (remove (cut valid-path? store <>) | |
280 | ',files))))) | |
281 | (count (length missing)) | |
282 | (port (store-import-channel session))) | |
283 | (format log-port (N_ "sending ~a store item to '~a'...~%" | |
284 | "sending ~a store items to '~a'...~%" count) | |
285 | count (session-get session 'host)) | |
286 | ||
287 | ;; Send MISSING in topological order. | |
288 | (export-paths local missing port) | |
289 | ||
290 | ;; Tell the remote process that we're done. (In theory the end-of-archive | |
291 | ;; mark of 'export-paths' would be enough, but in practice it's not.) | |
292 | (channel-send-eof port) | |
293 | ||
de9d8f0e LC |
294 | ;; Wait for completion of the remote process and read the status sexp from |
295 | ;; PORT. | |
296 | (let* ((result (false-if-exception (read port))) | |
297 | (status (zero? (channel-get-exit-status port)))) | |
987a29ba | 298 | (close-port port) |
de9d8f0e LC |
299 | (match result |
300 | (('success . _) | |
301 | missing) | |
302 | (('protocol-error message) | |
303 | (raise (condition | |
304 | (&nix-protocol-error (message message) (status 42))))) | |
305 | (('error key args ...) | |
306 | (raise (condition | |
307 | (&nix-protocol-error | |
308 | (message (call-with-output-string | |
309 | (lambda (port) | |
310 | (print-exception port #f key args)))) | |
311 | (status 43))))) | |
312 | (_ | |
313 | (raise (condition | |
314 | (&nix-protocol-error | |
315 | (message "unknown error while sending files over SSH") | |
316 | (status 44))))))))) | |
987a29ba LC |
317 | |
318 | (define (remote-store-session remote) | |
319 | "Return the SSH channel beneath REMOTE, a remote store as returned by | |
320 | 'connect-to-remote-daemon', or #f." | |
321 | (channel-get-session (nix-server-socket remote))) | |
322 | ||
323 | (define (remote-store-host remote) | |
324 | "Return the name of the host REMOTE is connected to, where REMOTE is a | |
325 | remote store as returned by 'connect-to-remote-daemon'." | |
326 | (match (remote-store-session remote) | |
327 | (#f #f) | |
328 | ((? session? session) | |
329 | (session-get session 'host)))) | |
330 | ||
e9629e82 LC |
331 | (define* (file-retrieval-port files remote |
332 | #:key recursive?) | |
987a29ba LC |
333 | "Return an input port from which to retrieve FILES (a list of store items) |
334 | from REMOTE, along with the number of items to retrieve (lower than or equal | |
335 | to the length of FILES.)" | |
e9629e82 LC |
336 | (values (store-export-channel (remote-store-session remote) files |
337 | #:recursive? recursive?) | |
338 | (length files))) ;XXX: inaccurate when RECURSIVE? is true | |
987a29ba | 339 | |
896fec47 LC |
340 | (define-syntax raise-error |
341 | (syntax-rules (=>) | |
342 | ((_ fmt args ... (=> hint-fmt hint-args ...)) | |
343 | (raise (condition | |
344 | (&message | |
345 | (message (format #f fmt args ...))) | |
346 | (&fix-hint | |
347 | (hint (format #f hint-fmt hint-args ...)))))) | |
348 | ((_ fmt args ...) | |
349 | (raise (condition | |
350 | (&message | |
351 | (message (format #f fmt args ...)))))))) | |
352 | ||
d06d54e3 LC |
353 | (define* (retrieve-files* files remote |
354 | #:key recursive? (log-port (current-error-port)) | |
355 | (import (const #f))) | |
356 | "Pass IMPORT an input port from which to read the sequence of FILES coming | |
357 | from REMOTE. When RECURSIVE? is true, retrieve the closure of FILES." | |
987a29ba | 358 | (let-values (((port count) |
e9629e82 LC |
359 | (file-retrieval-port files remote |
360 | #:recursive? recursive?))) | |
896fec47 LC |
361 | (match (read port) ;read the initial status |
362 | (('exporting) | |
363 | (format #t (N_ "retrieving ~a store item from '~a'...~%" | |
364 | "retrieving ~a store items from '~a'...~%" count) | |
365 | count (remote-store-host remote)) | |
366 | ||
d06d54e3 LC |
367 | (dynamic-wind |
368 | (const #t) | |
369 | (lambda () | |
370 | (import port)) | |
371 | (lambda () | |
372 | (close-port port)))) | |
896fec47 | 373 | ((? eof-object?) |
4eb0f9ae | 374 | (report-guile-error (remote-store-host remote))) |
896fec47 | 375 | (('module-error . _) |
4eb0f9ae | 376 | (report-module-error (remote-store-host remote))) |
896fec47 LC |
377 | (('connection-error file code . _) |
378 | (raise-error (G_ "failed to connect to '~A' on remote host '~A': ~a") | |
379 | file (remote-store-host remote) (strerror code))) | |
380 | (('invalid-items items . _) | |
381 | (raise-error (N_ "no such item on remote host '~A':~{ ~a~}" | |
382 | "no such items on remote host '~A':~{ ~a~}" | |
383 | (length items)) | |
384 | (remote-store-host remote) items)) | |
385 | (('protocol-error status message . _) | |
386 | (raise-error (G_ "protocol error on remote host '~A': ~a") | |
387 | (remote-store-host remote) message)) | |
388 | (_ | |
389 | (raise-error (G_ "failed to retrieve store items from '~a'") | |
390 | (remote-store-host remote)))))) | |
987a29ba | 391 | |
d06d54e3 LC |
392 | (define* (retrieve-files local files remote |
393 | #:key recursive? (log-port (current-error-port))) | |
394 | "Retrieve FILES from REMOTE and import them using the 'import-paths' RPC on | |
395 | LOCAL. When RECURSIVE? is true, retrieve the closure of FILES." | |
0e3c8528 LC |
396 | (retrieve-files* (remove (cut valid-path? local <>) files) |
397 | remote | |
d06d54e3 LC |
398 | #:recursive? recursive? |
399 | #:log-port log-port | |
400 | #:import (lambda (port) | |
401 | (import-paths local port)))) | |
402 | ||
4eb0f9ae LC |
403 | \f |
404 | ;;; | |
405 | ;;; Error reporting. | |
406 | ;;; | |
407 | ||
408 | (define (report-guile-error host) | |
409 | (raise-error (G_ "failed to start Guile on remote host '~A'") host | |
410 | (=> (G_ "Make sure @command{guile} can be found in | |
411 | @code{$PATH} on the remote host. Run @command{ssh ~A guile --version} to | |
412 | check.") | |
413 | host))) | |
414 | ||
415 | (define (report-module-error host) | |
416 | "Report an error about missing Guix modules on HOST." | |
417 | ;; TRANSLATORS: Leave "Guile" untranslated. | |
418 | (raise-error (G_ "Guile modules not found on remote host '~A'") host | |
419 | (=> (G_ "Make sure @code{GUILE_LOAD_PATH} includes Guix' | |
420 | own module directory. Run @command{ssh ~A env | grep GUILE_LOAD_PATH} to | |
421 | check.") | |
422 | host))) | |
423 | ||
987a29ba | 424 | ;;; ssh.scm ends here |