docker: Build tarballs reproducibly.

Fixes <https://issues.guix.gnu.org/75090>.

* guix/docker.scm (tar): New procedure.
(create-empty-tar, build-docker-image): Use it instead of calling
‘invoke’ directly.

Reported-by: Simon Josefsson <simon@josefsson.org>
Change-Id: Ia899c43ed6a3809ff845de0953e3d38cccf24609
This commit is contained in:
Ludovic Courtès 2025-01-07 23:52:17 +01:00
parent 35c6ae6e58
commit 646202bf73
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@ -1,6 +1,6 @@
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2017 Ricardo Wurmus <rekado@elephly.net>
;;; Copyright © 2017, 2018, 2019, 2021 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2017-2019, 2021, 2025 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2018 Chris Marusich <cmmarusich@gmail.com>
;;; Copyright © 2021 Maxim Cournoyer <maxim.cournoyer@gmail.com>
;;; Copyright © 2023 Oleg Pykhalov <go.wigust@gmail.com>
@ -171,8 +171,15 @@ Return a version of TAG that follows these rules."
(1- items-length)))))
(list head tail)))
(define (tar . arguments)
"Invoke 'tar' with the given ARGUMENTS together with options to build
tarballs in a reproducible fashion."
(apply invoke "tar" "--mtime=@1"
"--owner=0" "--group=0" "--numeric-owner"
"--sort=name" "--mode=go+u,go-w" arguments))
(define (create-empty-tar file)
(invoke "tar" "-cf" file "--files-from" "/dev/null"))
(tar "-cf" file "--files-from" "/dev/null"))
(define* (build-docker-image image paths prefix
#:key
@ -256,7 +263,7 @@ added to image as a layer."
(file-name (string-append file-hash "/layer.tar")))
(mkdir file-hash)
(rename-file "layer.tar" file-name)
(invoke "tar" "-rf" "image.tar" file-name)
(tar "-rf" "image.tar" file-name)
(delete-file file-name)
file-hash))
(define layers-hashes
@ -269,20 +276,20 @@ added to image as a layer."
(let* ((head-layers
(map
(lambda (file)
(invoke "tar" "cf" "layer.tar" file)
(tar "cf" "layer.tar" file)
(seal-layer))
head))
(tail-layer
(begin
(create-empty-tar "layer.tar")
(for-each (lambda (file)
(invoke "tar" "-rf" "layer.tar" file))
(tar "-rf" "layer.tar" file))
tail)
(let* ((file-hash (layer-diff-id "layer.tar"))
(file-name (string-append file-hash "/layer.tar")))
(mkdir file-hash)
(rename-file "layer.tar" file-name)
(invoke "tar" "-rf" "image.tar" file-name)
(tar "-rf" "image.tar" file-name)
(delete-file file-name)
file-hash)))
(customization-layer
@ -291,7 +298,7 @@ added to image as a layer."
(file-name (string-append file-hash "/layer.tar")))
(mkdir file-hash)
(rename-file file-id file-name)
(invoke "tar" "-rf" "image.tar" file-name)
(tar "-rf" "image.tar" file-name)
file-hash))
(all-layers
(append head-layers (list tail-layer customization-layer))))
@ -301,7 +308,7 @@ added to image as a layer."
(map (cut string-append <> "/layer.tar")
all-layers)
repository))))
(invoke "tar" "-rf" "image.tar" "manifest.json")
(tar "-rf" "image.tar" "manifest.json")
all-layers))))
(let* ((directory "/tmp/docker-image") ;temporary working directory
(id (docker-id prefix))
@ -390,7 +397,7 @@ added to image as a layer."
#:entry-point entry-point))))
(if max-layers
(begin
(invoke "tar" "-rf" "image.tar" "config.json")
(tar "-rf" "image.tar" "config.json")
(if compressor
(begin
(apply invoke `(,@compressor "image.tar"))