From 938ffcbb0589adc07dc12c79eda3e1e2bb9e7cf8 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ludovic=20Court=C3=A8s?= Date: Tue, 11 May 2021 15:01:00 +0200 Subject: [PATCH] publish: Add '--negative-ttl'. * guix/scripts/publish.scm (show-help, %options): Add '--negative-ttl'. (render-narinfo, render-narinfo/cached, make-request-handler): Add #:negative-ttl and honor it. (run-publish-server): Add #:narinfo-negative-ttl and honor it. (guix-publish): Honor '--negative-ttl'. * tests/publish.scm ("negative TTL", "no negative TTL"): New tests. --- doc/guix.texi | 10 ++++++++++ guix/scripts/publish.scm | 30 ++++++++++++++++++++++-------- tests/publish.scm | 32 +++++++++++++++++++++++++++++++- 3 files changed, 63 insertions(+), 9 deletions(-) diff --git a/doc/guix.texi b/doc/guix.texi index bfc714c5b6..a10943f2d5 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -12703,6 +12703,16 @@ Additionally, when @option{--cache} is used, cached entries that have not been accessed for @var{ttl} and that no longer have a corresponding item in the store, may be deleted. +@item --negative-ttl=@var{ttl} +Similarly produce @code{Cache-Control} HTTP headers to advertise the +time-to-live (TTL) of @emph{negative} lookups---missing store items, for +which the HTTP 404 code is returned. By default, no negative TTL is +advertised. + +This parameter can help adjust server load and substitute latency by +instructing cooperating clients to be more or less patient when a store +item is missing. + @item --cache-bypass-threshold=@var{size} When used in conjunction with @option{--cache}, store items smaller than @var{size} are immediately available, even when they are not yet in diff --git a/guix/scripts/publish.scm b/guix/scripts/publish.scm index 39bb224cad..ef6fa5f074 100644 --- a/guix/scripts/publish.scm +++ b/guix/scripts/publish.scm @@ -1,7 +1,7 @@ ;;; GNU Guix --- Functional package management for GNU ;;; Copyright © 2015 David Thompson ;;; Copyright © 2020 by Amar M. Singh -;;; Copyright © 2015, 2016, 2017, 2018, 2019, 2020 Ludovic Courtès +;;; Copyright © 2015, 2016, 2017, 2018, 2019, 2020, 2021 Ludovic Courtès ;;; Copyright © 2020 Maxim Cournoyer ;;; Copyright © 2021 Simon Tournier ;;; @@ -101,6 +101,8 @@ Publish ~a over HTTP.\n") %store-directory) --workers=N use N workers to bake items")) (display (G_ " --ttl=TTL announce narinfos can be cached for TTL seconds")) + (display (G_ " + --negative-ttl=TTL announce missing narinfos can be cached for TTL seconds")) (display (G_ " --nar-path=PATH use PATH as the prefix for nar URLs")) (display (G_ " @@ -224,6 +226,13 @@ usage." (leave (G_ "~a: invalid duration~%") arg)) (alist-cons 'narinfo-ttl (time-second duration) result)))) + (option '("negative-ttl") #t #f + (lambda (opt name arg result) + (let ((duration (string->duration arg))) + (unless duration + (leave (G_ "~a: invalid duration~%") arg)) + (alist-cons 'narinfo-negative-ttl (time-second duration) + result)))) (option '("nar-path") #t #f (lambda (opt name arg result) (alist-cons 'nar-path arg result))) @@ -390,14 +399,14 @@ References: ~a~%" (define* (render-narinfo store request hash #:key ttl (compressions (list %no-compression)) - (nar-path "nar")) + (nar-path "nar") negative-ttl) "Render metadata for the store path corresponding to HASH. If TTL is true, advertise it as the maximum validity period (in seconds) via the 'Cache-Control' header. This allows 'guix substitute' to cache it for an appropriate duration. NAR-PATH specifies the prefix for nar URLs." (let ((store-path (hash-part->path store hash))) (if (string-null? store-path) - (not-found request #:phrase "") + (not-found request #:phrase "" #:ttl negative-ttl) (values `((content-type . (application/x-nix-narinfo)) ,@(if ttl `((cache-control (max-age . ,ttl))) @@ -512,7 +521,7 @@ interpreted as the basename of a store item." (define* (render-narinfo/cached store request hash #:key ttl (compressions (list %no-compression)) - (nar-path "nar") + (nar-path "nar") negative-ttl cache pool) "Respond to the narinfo request for REQUEST. If the narinfo is available in CACHE, then send it; otherwise, return 404 and \"bake\" that nar and narinfo @@ -536,7 +545,7 @@ requested using POOL." #:compression (first compressions))))) (cond ((string-null? item) - (not-found request)) + (not-found request #:ttl negative-ttl)) ((file-exists? cached) ;; Narinfo is in cache, send it. (values `((content-type . (application/x-nix-narinfo)) @@ -584,7 +593,7 @@ requested using POOL." #:phrase "We're baking it" #:ttl 300))) ;should be available within 5m (else - (not-found request #:phrase ""))))) + (not-found request #:phrase "" #:ttl negative-ttl))))) (define (compress-nar cache item compression) "Save in directory CACHE the nar for ITEM compressed with COMPRESSION." @@ -974,7 +983,7 @@ methods, return the applicable compression." (define* (make-request-handler store #:key cache pool - narinfo-ttl + narinfo-ttl narinfo-negative-ttl (nar-path "nar") (compressions (list %no-compression))) (define compression-type? @@ -1006,10 +1015,12 @@ methods, return the applicable compression." #:cache cache #:pool pool #:ttl narinfo-ttl + #:negative-ttl narinfo-negative-ttl #:nar-path nar-path #:compressions compressions) (render-narinfo store request hash #:ttl narinfo-ttl + #:negative-ttl narinfo-negative-ttl #:nar-path nar-path #:compressions compressions))) ;; /nar/file/NAME/sha256/HASH @@ -1068,7 +1079,7 @@ methods, return the applicable compression." #:key advertise? port (compressions (list %no-compression)) - (nar-path "nar") narinfo-ttl + (nar-path "nar") narinfo-ttl narinfo-negative-ttl cache pool) (when advertise? (let ((name (service-name))) @@ -1084,6 +1095,7 @@ methods, return the applicable compression." #:pool pool #:nar-path nar-path #:narinfo-ttl narinfo-ttl + #:narinfo-negative-ttl narinfo-negative-ttl #:compressions compressions) concurrent-http-server `(#:socket ,socket))) @@ -1127,6 +1139,7 @@ methods, return the applicable compression." (user (assoc-ref opts 'user)) (port (assoc-ref opts 'port)) (ttl (assoc-ref opts 'narinfo-ttl)) + (negative-ttl (assoc-ref opts 'narinfo-negative-ttl)) (compressions (match (filter-map (match-lambda (('compression . compression) compression) @@ -1192,6 +1205,7 @@ consider using the '--user' option!~%"))) "publish worker")) #:nar-path nar-path #:compressions compressions + #:narinfo-negative-ttl negative-ttl #:narinfo-ttl ttl)))))) ;;; Local Variables: diff --git a/tests/publish.scm b/tests/publish.scm index 3e67c435ac..c3d086995a 100644 --- a/tests/publish.scm +++ b/tests/publish.scm @@ -1,7 +1,7 @@ ;;; GNU Guix --- Functional package management for GNU ;;; Copyright © 2015 David Thompson ;;; Copyright © 2020 by Amar M. Singh -;;; Copyright © 2016, 2017, 2018, 2019, 2020 Ludovic Courtès +;;; Copyright © 2016, 2017, 2018, 2019, 2020, 2021 Ludovic Courtès ;;; ;;; This file is part of GNU Guix. ;;; @@ -700,6 +700,36 @@ References: ~%" (= (response-content-length response) (stat:size (stat log))) (first (response-content-type response)))))) +(test-equal "negative TTL" + `(404 42) + + (call-with-temporary-directory + (lambda (cache) + (let ((thread (with-separate-output-ports + (call-with-new-thread + (lambda () + (guix-publish "--port=6786" "-C0" + "--negative-ttl=42s")))))) + (wait-until-ready 6786) + + (let* ((base "http://localhost:6786/") + (url (string-append base (make-string 32 #\z) + ".narinfo")) + (response (http-get url))) + (list (response-code response) + (match (assq-ref (response-headers response) 'cache-control) + ((('max-age . ttl)) ttl) + (_ #f)))))))) + +(test-equal "no negative TTL" + `(404 #f) + (let* ((uri (publish-uri + (string-append "/" (make-string 32 #\z) + ".narinfo"))) + (response (http-get uri))) + (list (response-code response) + (assq-ref (response-headers response) 'cache-control)))) + (test-equal "/log/NAME not found" 404 (let ((uri (publish-uri "/log/does-not-exist")))