Guide sur les paquets binaires
emerge — configuration — ebuild repository — dispatch-conf
world file — USE flags — ebuilds — profiles
upgrades — using testing packages — binary packages
tools — gentoolkit — eselect
Portage FAQ — cheat sheet — FAQ
all articles
Voir l'article démarrage rapide des paquets binaires pour plus d'informations pour l'utilisation des paquets binaires pré-compilés depuis l'hôte des paquets binaires de Gentoo.
Ce guide se concentrera sur l'utilisation des paquets binaires, la création, le partage et la maintenance, quelques sujets plus avancés sur la manière de fournir des paquets binaires sera traité près de la fin de celui-ci.
Portage supporte les paquets binaires en plus de son support bien connu pour des ebuilds basés sur le code source (NdT: compilation). Portage peut être utilisé pour créer des paquets binaires, pour les installer, ou mettre à jour ceux déjà présents sur le système depuis des paquets binaires. Portage peut récupérer les binaires depuis les hôtes de paquets binaires.
Tous les outils utilisés dans ce guide font partie de sys-apps/portage, sauf mention contraire.
Pourquoi utiliser les paquets binaires sur Gentoo ?
Il y a de nombreuses raisons qui expliquent que les administrateurs système aiment utiliser des paquets binaires sur Gentoo :
- Économiser du temps tout en gardant aussi bien le système à jour. Compiler depuis les sources peut prendre plus de temps qu'en installant depuis un paquet binaire. Une approche différente est de faire ces mises à jours dans un chroot sur le même système et utiliser les binaires crées à cet emplacement pour mettre à jour le vrai système.
- Faire des mises à jour sûres. Pour des systèmes critiques en production il est important de rester utilisable autant que possible. Cela peut être réalisé à travers un serveur intermédiaire pour faire les mises à jours pour lui-même. Une fois que le serveur intermédiaire est fonctionnel les mises à jours peuvent être appliqué vers le système critique avec des paquets binaires pour le système hôte.
- En tant que sauvegarde. Parfois, les paquets binaires sont le seul moyen de réparer un système endommagé (exemple: compilateur cassé). Avoir des paquets pré-compilé dans un coin, soit sur un serveur de binaires ou localement, peut être d'une aide importante dans le cas d'une chaîne de compilation non-fonctionnel.
- Cela peut aider à mettre un jour un système très vieux. Mettre à jour un très vieux système cela peut être facilité via l'utilisation de paquets binaires. Il est généralement utile d'installer des paquets binaires sur des vieux systèmes car ils ne requièrent pas de compiler des dépendances pour l'installation / mise à jours. Les paquets binaires peuvent permettre d'éviter des erreurs lors de la compilation.
Formats d'un paquet binaire
Deux types de formats de paquet existent pour Gentoo, XPAK et GPKG. Depuis v3.0.31, il supporte le nouveau format de paquet binaire GPKG. Le format GPKG résout des problèmes avec le format historique XPAK et offre les bénéfices de nouvelles fonctionnalités, cependant il n'y a pas de rétro-compatibilité avec le format historique XPAK.
Les administrateurs système utilisant une vieille version de Portage (<=v3.0.30) devraient utiliser le format XPAK, qui est le paramétrage par défaut de Portage.
Les raisons d'utiliser le nouveau format GPKG peuvent être trouver dans GLEP 78: Gentoo binary package container format. Les bugs bug #672672 et bug #820578 procurent aussi des détails utiles.
Pour demander à Portage d'utiliser le format GPKG, changer la valeur de BINPKG_FORMAT dans /etc/portage/make.conf.
BINPKG_FORMAT="gpkg"
Ce guide s'adapte généralement aux deux formats, cela sera noté où ce n'est pas le cas. Voir la section comprendre le format de paquet binaires pour des détails techniques sur le format des paquets binaires en lui-même.
Utiliser des paquets binaire
Pré-requis généraliste
Pour qu'un paquet binaire puisse être utilisable sur un autre système ils doivent respecter ces pré-requis :
- L'architecture du compilateur et du client doivent avoir la même valeur CHOST.
- Les variables CFLAGS et CXXFLAGS doivent être compatibles avec tout les clients.
- Les USE flags pour les fonctionnalités spécifiques aux instructions du processeur (comme MMX, SSE, etc.) doivent être sélectionnés avec prudence, tout les clients doivent les supporter.
Les paquets binaires sont distribués en tant que partie officielle du projet binhost de Gentoo et utilise un jeu d'instructions minimum et des paramètres de conservation du compilateur de manière à être le plus largement utilisable autant que faire se peut. À titre d'exemple, le mot-clé amd64 paramétré pour des paquets construit avec les options
-march=x86-64 -mtune=generic
et qui fonctionne sur n'importe quelle machine qui tourne avec le jeu d'instructions de x86-64 (amd64).Portage ne peut pas valider (NdT: ces paquets) si c'est pré-requis ne sont pas correspondants. En cas de doutes, il est de la responsabilités de l'administrateur de s'assurer de la validité de ces paramètres.
Gérer les *FLAGS en détail
L'utilitaire app-misc/resolve-march-native peut être trouvé dans une sous-suite de CFLAGS qui est supporté par à la fois le serveur et le(s) client(s). Par exemple, l'hôte peut retourner :
user $
resolve-march-native
-march=skylake -mabm -mrtm --param=l1-cache-line-size=64 --param=l1-cache-size=32 --param=l2-cache-size=12288
Pendant ce temps là le client peut retourner :
user $
resolve-march-native
-march=ivybridge -mno-rdrnd --param=l1-cache-line-size=64 --param=l1-cache-size=32 --param=l2-cache-size=3072
Dans cet exemple CFLAGS peut être paramétré avec -march=ivybridge -mno-rdrnd
avec -march=ivybridge
qui est une sous-suite de -march=skylake
. -mabm
et -mrtm
ne sont pas supporté par le client. Cependant, -mno-rdrnd
est inclus comme le client ne supporte pas -mrdrnd
. Pour trouver quel -march
est une sous-suite, vérifier le manuel de GCC, s'il n'y a pas de sous-suite comme -march=x86-64
.
Optionally, it is also possible to set -mtune=some-arch
or -mtune=native
to tell gcc to tune code to a specific arch. In contrast to -march
, the -mtune
argument does not prevent code from being executed on other processors. For example, to compile code which is compatible with ivybridge and up but is tuned to run best on skylake set CFLAGS to -march=ivybridge -mtune=skylake
. When -mtune
is not set it defaults to whatever -march
is set to.
When changing -march
to a lower subset for using binary packages on a client, a full recompilation is required to make sure that all binaries are compatible with the client's processor, to save time packages that are not compiled with e.g. gcc/clang can be excluded:
user $
emerge -e @world --exclude="acct-group/* acct-user/* virtual/* app-eselect/* sys-kernel/* sys-firmware/* dev-python/* dev-java/* dev-ruby/* dev-perl/* dev-lua/* dev-php/* dev-tex/* dev-texlive/* x11-themes/* */*-bin"
Similarly, app-portage/cpuid2cpuflags can be used to find a suitable subset of processor specific instruction set USE flags. For example, the host might return:
user $
cpuid2cpuflags
CPU_FLAGS_X86: aes avx avx2 f16c fma3 mmx mmxext pclmul popcnt rdrand sse sse2 sse3 sse4_1 sse4_2 ssse3
While the client might return:
user $
cpuid2cpuflags
CPU_FLAGS_X86: avx f16c mmx mmxext pclmul popcnt sse sse2 sse3 sse4_1 sse4_2 ssse3
In this example CPU_FLAGS_X86 can be set to avx f16c mmx mmxext pclmul popcnt sse sse2 sse3 sse4_1 sse4_2 ssse3
in /etc/portage/make.conf because these flags are supported by both the client and the host
Next to these, Portage can check if the binary package is built using the same USE flags as expected on the client. Unless using --usepkgonly
(-K
) or --getbinpkgonly
(-G
), if a package is built with a different USE flag combination, Portage will either ignore the binary package (and use source-based build) or fail, depending on the options passed to the emerge command upon invocation (see Installing binary packages).
On clients, a few configuration changes are needed in order for the binary packages to be used.
Installer des paquets binaires
There are a few options that can be passed on to the emerge command that inform Portage about using binary packages:
Option | Description |
---|---|
--usepkg (-k ) |
Tries to use the binary package(s) in the locally available packages directory. Useful when using NFS or SSHFS mounted binary package hosts. If the binary packages are not found, a regular (source-based) installation will be performed. |
--usepkgonly (-K ) |
Similar to --usepkg (-k ) but fail if the binary package cannot be found. This option is useful if only pre-built binary packages are to be used.
|
--getbinpkg (-g ) |
Download the binary package(s) from a remote binary package host. If the binary packages are not found, a regular (source-based) installation will be performed. |
--getbinpkgonly (-G ) |
Similar to --getbinpkg (-g ) but will fail if the binary package(s) cannot be downloaded. This option is useful if only pre-built binary packages are to be used.
|
In order to automatically use binary package installations, the appropriate option can be added to the EMERGE_DEFAULT_OPTS variable:
EMERGE_DEFAULT_OPTS="${EMERGE_DEFAULT_OPTS} --getbinpkg"
There is a Portage feature that automatically implements the equivalent of --getbinpkg
(-g
) without the need for updating the EMERGE_DEFAULT_OPTS variable with the --getbinpkg
value:
FEATURES="getbinpkg"
Verify binary package OpenPGP signatures
OpenPGP signing and verification is only available for the GPKG binpkg format.
Portage will try to verify the binary package's signature whenever possible, but users must first set up trusted local keys. app-portage/getuto can be used to set up a local trust anchor and update the keys in /etc/portage/gnupg. Portage calls getuto automatically with --getbinpkg or --getbinpkgonly.
This configures portage such that it trusts the Gentoo Release Engineering keys as also contained in the package sec-keys/openpgp-keys-gentoo-release for binary installation purposes.
Changes to the configuration can be done as root using gpg
with the parameter --homedir=/etc/portage/gnupg
. This way allows importing additional signing keys (e.g. for non-standard installation sources) and declare them as trusted.
To add a custom signing key:
- Generate (or use an existing) key with signing abilities, and export the public key to a file.
- Run
getuto
if it has never run:root #
getuto
- Use
gpg --homedir=/etc/portage/gnupg --import public.key
to import the public key in portage's keyring. - Trust and sign this key using the key created by
getuto
. In order to do this, first get the password to unlock the key at /etc/portage/gnupg/pass, then use:Typeroot #
gpg --homedir=/etc/portage/gnupg --edit-key YOURKEYID
sign
,yes
, paste (or type) the password. The key is now signed. To trust it, typetrust
, then4
to trust it fully. Finally, typesave
. - Update the trustdb so that GPG considers the key valid:
root #
gpg --homedir=/etc/portage/gnupg --check-trustdb
If you hit any issues, check if a pre-existing /etc/portage/gnupg existed. If it did, move it away and then repeat the above steps.
Congratulations, Portage now has a working keyring!
Trusting the key marginally or less will not work
By default, Portage will only verify GPG signatures when a signature file is found in a package, which allows the user to mix signed and unsigned GPKG binary packages from different sources, and allows to use old XPAK format binary packages.
If the user wishes to force signature verification, the binpkg-request-signature
feature needs to be enabled. This feature assumes that all packages should be signed and rejects any unsigned package. Note that this feature does not support per-binhost configuration.
# Require that all binpkgs be signed and reject them if they are not (or have an invalid sig)
FEATURES="binpkg-request-signature"
Pulling packages from a binary package host
"The PORTAGE_BINHOST variable is deprecated in favor of the /etc/portage/binrepos.conf configuration file" - make.conf(5)
When using a binary package host, clients need to have the PORTAGE_BINHOST variable set in /etc/portage/make.conf or the sync-uri variable in /etc/portage/binrepos.conf. Without this configuration, the client will not know where the binary packages are stored which results in Portage being unable to retrieve them.
[binhost]
sync-uri = https://example.com/binhost
priority = 10
For each binhost, a name can be configured in the brackets. sync-uri must point to the directory in which the Packages file resides. Optionally, priority can be set. When a package exists in multiple binary package repositories, the package is pulled from the binary package host with the highest priority. This way, a preferred binary package host can be set up.
Many Gentoo stages already come with a preinstalled /etc/portage/binrepos.conf file, which points to the corresponding binary packages generated during the stage builds.
The support for multiple binary package servers is somewhat incomplete. If several servers serve a binary package for the same package version, then only the first one will be considered. This can be problematic when these binary packages differ in their USE variable configuration and the USE variable configuration of a later binary package would match the systems configuration.
Réinstaller des paquets binaires modifiés
Passing the --rebuilt-binaries
option to emerge will reinstall every binary that has been rebuilt since the package was installed. This is useful in case rebuilding tools like revdep-rebuild are run on the binary package server.
A related option is --rebuilt-binaries-timestamp
. It causes emerge not to consider binary packages for a re-install if those binary packages have been built before the given time stamp. This is useful to avoid re-installing all packages, if the binary package server had to be rebuild from scratch but --rebuilt-binaries
is used otherwise.
Additional client settings
Next to the getbinpkg
feature, Portage also listens to the binpkg-logs
feature. It controls if log files for successful binary package installations should be kept. It is only relevant if the PORT_LOGDIR variable has been set and is enabled by default.
Similar to excluding binary packages for a certain set of packages or categories, clients can be configured to exclude binary package installations for a certain set of packages or categories.
To accomplish this, use the --usepkg-exclude
option:
root #
emerge -uDNg @world --usepkg-exclude "sys-kernel/gentoo-sources virtual/*"
To enable such additional settings for each emerge command, add the options to the EMERGE_DEFAULT_OPTS variable in the make.conf file:
EMERGE_DEFAULT_OPTS="${EMERGE_DEFAULT_OPTS} --usepkg-exclude 'sys-kernel/gentoo-sources virtual/*'"
Updating packages on the binary package host
Do not use
--changed-use
(-U
) when updating packages on the binary package host, doing so will cause packages with added or removed USE flags to be skipped, which will cause their installation from binary package on the client to fail due to non-matching USE between the source ebuild and binary package (if the client's --binpkg-respect-use=y
, the default). Use --newuse
(-N
), which will always rebuild packages even for added or removed USE flags, ensuring the binary package stays in sync with the source ebuild.Créer des paquets binaires
Il y a trois méthodes principales pour créer des paquets binaires :
- Après une installation standard, utiliser l'application quickpkg.
- Explicitement, au cours d'une opération emerge en utilisant l'option
--buildpkg
(-b
) - Automatiquement, en utilisant la valeur de
buildpkg
pour la variable FEATURES de Portage.
Les trois méthodes créeront un paquet binaire dans le répertoire indiqué par la variable PKGDIR (qui par défaut prend la valeur /var/cache/binpkgs).
Utilisation de --buildpkg comme option de emerge
Lorsque l'installation du logiciel est opérée par emerge, Portage peut installer des fichiers binaires si l'option --buildpkg
(-b
) est ajoutée à la ligne de commande :
root #
emerge --ask --buildpkg sys-devel/gcc
Il est aussi possible de demander à Portage de créer seulement un paquet binaire mais sans installer le logiciel sur le système à chaud. Dans ce cas, utiliser l'option --buildpkgonly
(-B
) :
root #
emerge --ask --buildpkgonly sys-devel/gcc
Cette dernière approche nécessite toutefois que toutes les dépendances de compilation soient préalablement installées.
Utilisation de buildpkg comme variable FEATURE de Portage
La façon la plus courante de créer automatiquement des paquets binaires lorsqu'un paquet est installé par Portage est d'utiliser la fonctionnalité buildpkg
, qui peut être spécifiée comme suit dans /etc/portage/make.conf:
FEATURES="buildpkg"
Une fois cette fonctionnalité activée, chaque fois que Portage installera un logiciel, il créera un paquet binaire également.
Comment exclure la création de certains paquets
Il est possible de dire à Portage de ne pas créer de paquets binaires pour quelques paquets ou catégories sélectionnés. Cela se fait en passant l'option --buildpkg-exclude
à emerge :
root #
emerge -uDN @world --buildpkg --buildpkg-exclude "virtual/* sys-kernel/*-sources"
Cette façon de faire peut être retenue pour les paquets dont le déploiement au format binaire ne présente que peu ou pas d'avantage. Des exemples pourraient être les paquets source du noyau Linux ou les packages binaires déployés en amont (ceux se terminant par -bin comme www-client/firefox-bin).
Binary package compression formats
It is possible to use a specific compression type on binary packages. Currently, the following formats are supported: bzip2
, gzip
, lz4
, lzip
, lzop
, xz
, and zstd
. Defaults to zstd
. Review man make.conf and search for BINPKG_COMPRESS for the most up-to-date information.
The compression format can be specified via make.conf.
BINPKG_COMPRESS="lz4"
Note that the compression type used might require extra dependencies to be installed, for example, in this case app-arch/lz4.
Binary package OpenPGP signing
OpenPGP signing and verification is only available for the GPKG binpkg format.
A PGP signature enables Portage to check the creator and integrity of a binary package, and to perform trust management based on PGP keys. The binary package signing feature is disabled by default. To use it, enable the binpkg-signing
feature. Note that whether this feature is enabled does not affect the signature verification feature.
FEATURES="binpkg-signing"
Users also need to set the BINPKG_GPG_SIGNING_GPG_HOME and BINPKG_GPG_SIGNING_KEY variables for Portage to find the signing key.
BINPKG_GPG_SIGNING_GPG_HOME="/root/.gnupg"
BINPKG_GPG_SIGNING_KEY="0x1234567890ABCDEF"
Portage will only try to unlock the PGP private key at the beginning. If the user's key will expire over time, then consider enabling gpg-keepalive
to prevent signing failures.
FEATURES="gpg-keepalive"
gpg-agent by default expires cache entries after 2 hours. This means that, by default, if an emerge session lasts longer than 2 hours, signing of binpkgs will eventually fail regardless of FEATURES="gpg-keepalive". To prevent this problem, set max-cache-ttl to some large value (e.g. 34560000) in $BINPKG_GPG_SIGNING_GPG_HOME/gpg-agent.conf.
Utilisation de quickpkg
L'application quickpkg prend comme argument un ou plusieurs atomes (ou ensembles de paquets) et crée des paquets binaires pour tous les paquets "installés" qui leur correspondent.
Attention, cette méthode doit être utilisée avec prudence, car elle part des fichiers installés, ce qui peut poser problème en cas de fichiers de configurations spécifiques à la machine source. Les administrateurs changent souvent ces fichiers de configuration après avoir installé les logiciels. Dès lors que l'inclusion des fichiers de configuration pourrait poser des problèmes de diffusion de données importantes (et parfois même confidentielles) dans les paquets, par défaut quickpkg n'inclut pas les fichiers de configuration qui sont protégés par la méthode CONFIG_PROTECT. Pour forcer l'inclusion de ces fichiers de configuration, utiliser les options --include-config
ou --include-unmodified-config
.
Par exemple, pour créer les paquets binaires de toutes les versions installées de GCC :
root #
quickpkg sys-devel/gcc
To create binary packages for the system set:
root #
quickpkg @system
Pour créer les paquets binaires de tous les paquets installés sur le système, utiliser le glob *
:
root #
quickpkg "*/*"
Mise en place d'un serveur de paquets binaires
Portage prend en charge un certain nombre de protocoles pour télécharger des paquets binaires : FTP, FTPS, HTTP, HTTPS et SSH/SFTP. Cela permet d'envisager de nombreuses implémentations éventuelles de serveurs de paquets binaires.
Il n'y a cependant aucune méthode "prête à l'emploi" fournie par Portage pour distribuer des paquets binaires. Selon la configuration souhaitée, des logiciels supplémentaires devront être installés.
Un serveur de paquets binaires sur Internet
Une approche courante pour distribuer des packages binaires consiste à créer un hôte de packages binaires raccordé à Internet.
HTTPD
Utilisez un serveur Web tel que lighttpd (www-servers/lighttpd) et configurez-le pour fournir un accès en lecture à l'emplacement de la variable PKGDIR de /etc/portage/make.conf.
# Ajouter ceci à la fin de la configuration standard
server.modules += ( "mod_alias" )
alias.url = ( "/packages" => "/var/cache/binpkgs/" )
Caddy
To set up the Caddy HTTP server to provide a web-based binary package host, create a Caddyfile
containing:
x.x.x.x:80 { # Replace x.x.x.x with your host's IPv4 address
root * /path/to/binhost/var/cache/binpkgs
file_server browse # Needed to server
}
Once that is created, run Caddy with:
root #
caddy run --config /path/to/Caddyfile
Puis, sur les systèmes clients, configurer la variable PORTAGE_BINHOST en conséquence:
PORTAGE_BINHOST="http://binhost.example.com/packages"
SSH binary package host
To provide an authenticated approach for binary package mirrors, Portage can be configured to use the SSH protocol to access binary packages.
When using SSH, it is possible to use the root Linux user's SSH key (without passphrase as the installations need to happen in the background) to connect to a remote binary package host.
To accomplish this, make sure that the root user's SSH key is allowed on the server. This will need to happen for each machine that will connect to the SSH capable binary host:
root #
cat root.id_rsa.pub >> /home/binpkguser/.ssh/authorized_keys
The PORTAGE_BINHOST variable could then look like so:
PORTAGE_BINHOST="ssh://binpkguser@binhostserver/var/cache/binpkgs"
If the SSH server is listening to a different port (e.g 25), then it must be specified after the address, like so:
PORTAGE_BINHOST="ssh://binpkguser@binhostserver:25/var/cache/binpkgs"
Do not use the SSH configuration files found in ~/.ssh/config for setting ports or username. This location is ignored when Portage tries to rsync the packages back onto the client. Instead set all the options correctly in the PORTAGE_BINHOST variable.
NFS exported
When using binary packages on an internal network, it might be easier to export the packages through NFS and mount it on the clients.
The /etc/exports file could look like so:
/var/cache/binpkgs 2001:db8:81::/48(ro,no_subtree_check,root_squash) 192.168.100.0/24(ro,no_subtree_check,root_squash)
On the clients, the location can then be mounted. An example /etc/fstab entry would look like so:
binhost:/var/cache/binpkgs /var/cache/binpkgs nfs defaults 0 0
The NFS share is mounted on the local filesystem, so there is no need to set PORTAGE_BINHOST or use the --getbinpkg
option. Instead, follow the normal procedures for installing binary packages, remembering to point PKGDIR to the NFS share so that portage knows where to find the packages:
PKGDIR="/var/cache/binpkgs"
If PKGDIR is network-mounted, it may be advantageous to enable
FEATURES="pkgdir-index-trusted"
. This feature disables checking the entire PKGDIR for added or removed packages and instead trusts the contents of the Packages
file to be accurate. This significantly improves performance on high-latency networks.Maintaining binary packages
Exporting and distributing the binary packages will lead to useless storage consumption if the binary package list is not actively maintained.
Removing outdated binary packages
In the gentoolkit package an application called eclean is provided. It allows for maintaining Portage-related variable files, such as downloaded source code files, but also binary packages.
The following command will remove all binary packages that have no corresponding ebuild in the installed ebuild repositories:
root #
eclean packages
For more details please read the eclean article.
Another tool that can be used is the qpkg tool from the app-portage/portage-utils package. However, this tool is a bit less configurable.
To clean up unused binary packages (in the sense of used by the server on which the binary packages are stored):
root #
qpkg -c
Maintaining the Packages file
As of portage-3.0.52, Portage defaults to
FEATURES=pkgdir-index-trusted
for performance, which requires an accurate Packages index. This can be disabled if it is an inconvenience to regularly fix up the index with emaint after manual changes.Inside the packages directory exists a manifest file called Packages. This file acts as a cache for the metadata of all binary packages in the packages directory. The file is updated whenever Portage adds a binary package to the directory. Similarly, eclean updates it when it removes binary packages.
If for some reason binary packages are simply deleted or copied into the packages directory, or the Packages file gets corrupted or deleted, then it must be recreated. This is done using emaint command:
root #
emaint binhost --fix
To clear the cache of all binary packages:
root #
rm -r /var/cache/binpkgs/*
Advanced topics
Chrooting
If creating packages for a different Portage profile or system with different USE flags, a chroot can be created.
This example uses /var/chroot/buildenv as the chroot path, but any path can be used.
Creating the directories
First, the directories for this chroot must be created:
root #
mkdir --parents /var/chroot/buildenv
Deploying the build environment
Next, the appropriate stage 3 tarball must be downloaded and extracted, here the desktop profile | openrc tarball is being used:
This can be extracted with the following command:
/var/chroot/buildenv/ #
tar xpvf stage3-*.tar.xz --xattrs-include='*.*' --numeric-owner
Configuring the build environment
{{{1}}}
The build environment should be configured to match that of the system it is building for. The simplest way to do this is to copy the /etc/portage and /var/lib/portage/world files. This can be done with rsync:
This command should be executed on the build target machine, where the remote host has the chroot.
user $
rsync --archive --whole-file --verbose /etc/portage/* larry@remote_host:/var/chroot/buildenv/etc/portage
user $
rsync --archive --whole-file --verbose /var/db/repos/* larry@remote_host:/var/chroot/buildenv/var/db/repos
{{{1}}}
This process should be repeated for the world file:
user $
rsync --archive --whole-file --verbose /var/lib/portage/world larry@remote_host:/var/chroot/buildenv/var/lib/portage/world
/var/lib/portage and /var/lib/portage/world should have the
root:portage
permissions.Configuring the chroot
Once created, mounts must be bound for the chroot to work:
/var/chroot/buildenv #
mount --types proc /proc proc
/var/chroot/buildenv #
mount --rbind /dev dev
/var/chroot/buildenv #
cp --dereference /etc/resolv.conf etc
Entering the chroot
To enter this chroot, the following command can be used:
/var/chroot/buildenv #
chroot . /bin/bash
Optionally, the prompt can be set to reflect the fact that the chroot is active:
/ #
export PS1="(chroot) $PS1"
Performing an initial build
This step assumes this configuration has been completed: Setting portage to use buildpkg.
This step is optional, but rebuilds all packages in the new world:
(chroot) #
emerge --emptytree @world
Building for other architectures
crossdev is a tool to easily build cross-compile toolchains. This is useful to create binary packages for installation on a system whose architecture differs from that of the system used to build the packages. A common example would be building binary packages for a device like an arm64 Raspberry Pi from a more powerful amd64 desktop PC.
An installation guide for sys-devel/crossdev can be found at the crossdev page.
Build a cross compiler
Using crossdev with the following command can build a toolchain for the desired system:
root #
crossdev --stable -t <arch-vendor-os-libc>
For the rest of this section, the example target will be for a Raspberry Pi 4:
root #
crossdev --stable -t aarch64-unknown-linux-gnu
After this has built, a toolchain will have been created in /usr/aarch64-unknown-linux-gnu, and will look like a bare-bones Gentoo install where it is possible to edit Portage settings as normal.
Replacing
aarch64-unknown-linux-gnu
with aarch64-unknown-linux-musl
would build a system with the Musl libc rather than Glibc.Basic setup
Removing the -pam
flag from the USE line in /usr/aarch64-unknown-linux-gnu/etc/portage/make.conf is generally recommended in a setup like this:
CHOST=aarch64-unknown-linux-gnu
CBUILD=x86_64-pc-linux-gnu
ROOT=/usr/${CHOST}/
ACCEPT_KEYWORDS="${ARCH}"
USE="${ARCH}"
CFLAGS="-O2 -pipe -fomit-frame-pointer"
CXXFLAGS="${CFLAGS}"
FEATURES="-collision-protect sandbox buildpkg noman noinfo nodoc"
# Ensure pkgs from another repository are not overwritten
PKGDIR=${ROOT}var/cache/binpkgs/
#If you want to redefine PORTAGE_TMPDIR uncomment (and/or change the directory location) the following line
PORTAGE_TMPDIR=${ROOT}var/tmp/
PKG_CONFIG_PATH="${ROOT}usr/lib/pkgconfig/"
#PORTDIR_OVERLAY="/var/db/repos/local/"
Profiles
List available profiles for the device by running:
root #
PORTAGE_CONFIGROOT=/usr/aarch64-unknown-linux-gnu eselect profile list
Next, select the profile that best suits:
root #
PORTAGE_CONFIGROOT=/usr/aarch64-unknown-linux-gnu eselect profile set <profile number>
Build a single package
To build a single binary package for use on the device, use the following:
root #
emerge-aarch64-unknown-linux-gnu --ask foo
Build world file
To build every package in the world file, then the following command is needed:
root #
emerge-aarch64-unknown-linux-gnu --emptytree @world
Binary location
By default, all binary packages will be stored in /usr/aarch64-unknown-linux-gnu/var/cache/binpkgs, so this is the location needed to be selected when setting up a binary package host.
Creating snapshots of the packages directory
When deploying binary packages for a large number of client systems it might become worthwhile to create snapshots of the packages directory. The client systems then do not use the packages directory directly but use binary packages from the snapshot.
Snapshots can be created using the /usr/lib/portage/python3.11/binhost-snapshot tool that comes with Portage (note that the path to that tool may need to be adjusted to match the python version with which Portage is installed). It takes four arguments:
- A source directory (the path to the packages directory).
- A target directory (that must not exist).
- A URI.
- A binary package server directory.
The files from the package directory are copied to the target directory. A Packages file is then created inside the binary package server directory (fourth argument) with the provided URI.
Client systems need to use an URI that points to the binary package server directory. From there they will be redirected to the URI that was given to binhost-snapshot. This URI has to refer to the target directory.
Comprendre le format des paquets binaires
XPAK format
XPAK format binary packages created by Portage have the file name ending with .tbz2. These files consist of two parts:
- A .tar.bz2 archive containing the files that will be installed on the system.
- A xpak archive containing package metadata, the ebuild, and the environment file.
See man xpak for a description of the format.
In app-portage/portage-utils some tools exists that are able to split or create tbz2 and xpak files.
The following command will split the tbz2 into a .tar.bz2 and an .xpak file:
user $
qtbz2 -s <paquet>.tbz2
The .xpak file can be examined using the qxpak utility.
To list the contents:
user $
qxpak -l <paquet>.xpak
The next command will extract a file called USE which contains the enabled USE flags for this package:
user $
qxpak -x package-manager-0.xpak USE
GPKG format
GPKG format binary packages created by Portage have the file name ending with .gpkg.tar. These files consist of four parts at least:
- A gpkg-1 empty file that used to identify the format.
- A C/PV/metadata.tar{.compression} archive containing package metadata, the ebuild, and the environment file.
- A C/PV/image.tar{.compression} archive containing the files that will be installed on the system.
- A Manifest file containing checksums to protect against file corruption.
- Multiple optional .sig files containing OpenPGP signature are used for integrity checking and verification of trust.
The format can be extracted by tar without the need for additional tools.
The PKGDIR layout
The currently used format version 2 has the following layout:
PKGDIR
`+- Packages
+- app-accessibility/
| +- pkg1-version.tbz2
| `- pkgN-version.tbz2
+- app-admin/
| `- ...
`- ...
The Packages file is the major improvement (and also the trigger for Portage to know that the binary package directory uses version 2) over the first binary package directory layout (version 1). In version 1, all binary packages were also hosted inside a single directory (called All/) and the category directories only had symbolic links to the binary packages inside the All/ directory.
In portage-3.0.15 and later, FEATURES=binpkg-multi-instance
is enabled by default:
PKGDIR
`+- Packages
+- app-accessibility/
| +- pkg1/
| +- pkg1-version-build_id.xpak
| `- pkgN-version-build_id.xpak
+- app-admin/
| `- ...
`- ...
Unpacking with quickunpkg
Zoobab wrote a simple shell tool named quickunpkg to quickly unpack tbz2 files.
See also
- Binary package quickstart — using the fully-supported Gentoo binary package host for amd64 and arm64 with the settings the packages are compiled with
- Emerge — la principale interface en ligne de commande de Portage
- Portage — gestionnaire de paquet et le système de distribution officiel de Gentoo.
- Project:Binhost — aims to provide readily installable, precompiled packages for a subset of configurations, via central binary package hosting
External resources
quickpkg man page.