Binary package guide/de

Next to the usual support for ebuilds, Portage supports building and installing binary packages. This guide explains how to create them, install them, and how to setup a binary package server.

Einleitung
Es gibt viele Gründe weshalb einige Systemadministratoren die Verwendung von Binärpaket-Installationen in Gentoo mögen.


 * 1) Zuallererst erlaubt es Administratoren ähnliche Systeme aktuell zu halten. Alles aus den Quellen kompilieren zu müssen, kann zeitaufwändig werden. Die Wartung einiger ähnlicher Systeme, möglicherweise einige von ihnen mit älterer Hardware, kann sehr viel einfacher sein, wenn nur ein System alles aus den Quellen kompilieren muss und die anderen Systeme die Binärpakete wiederverwenden.
 * 2) Ein zweiter Grund ist sichere Updates durchzuführen. Für missionskritische Systeme ist es wichtig soweit wie möglich benutzbar zu bleiben. Dies kann durch Staging-Server erreicht werden, die alle Updates zuerst bei sich selbst durchführen. Sobald der Staging-Server (wieder) in einem guten Zustand ist, können die Updates auf das kritische System angewandt werden. Eine Variante dieses Ansatzes ist die Updates in einer chroot-Umgebung auf dem selben System durchzuführen und die hierbei erzeugten Binärdateien dann im richtigen System zu benutzen.
 * 3) Ein dritter Grund ist als ein Backup. Oft sind Binärpakete der einzige Weg ein kaputtes System wiederherzustellen (z.B. kaputter Kompiler). Vorkompilierte Binärpakete bei der Hand zu haben, entweder auf einem Binärpaket-Server oder lokal, kann im Falle einer defekten Toolchain eine große Hilfe sein.
 * 4) Und schließlich erlaubt es ebenfalls sehr alte Systeme upzudaten. Die Aufgabe sehr alte Systeme upzudaten kann durch die Verwendung von Binärpaketen stark vereinfacht werden. Es ist für gewöhnlich hilfreich Binärpakete auf alten Systemen zu installieren weil sie keine Build-Time Abhängigkeiten erfordern, die installiert/ upgedated werden müssten. Binär-Pakete vermeiden ebenfalls Fehler in Build-Prozessen, weil sie vorkompiliert sind.

This guide will focus on the following topics:


 * How to create binary packages;
 * How to distribute the packages to clients;
 * How to use binary packages;
 * How to maintain the binary packages.

Nahe am Ende werden ein paar fortgeschrittenere Themen zum Umgang mit Binärpaketen behandelt.

Binärpakete erzeugen
There are three main methods for creating binary packages:


 * 1) After a regular installation, using the  application;
 * 2) Explicitly during an  operation by using the   option;
 * 3) Automatically through the use of the   as a Portage feature.

All three methods will create a binary package in the directory pointed to by the PKGDIR variable (which defaults to ).

Benutzung von quickpkg
The application takes one or more dependency atoms (or package sets) and creates binary packages for all installed packages that match that atom.

Um beispielsweise von allen installierten GCC-Versionen Binärpakete zu erstellen:

Um Binärpakete von allen auf dem System installierten Paketen zu schaffen, verwenden Sie  glob:

There is a caveat with this method: it relies on the installed files, which can be a problem in case of configuration files. Administrators often change configuration files after installing software. Because this could leak out important (perhaps even confidential) data into the packages, by default does not include configuration files that are protected through the CONFIG_PROTECT method. To force inclusion of configuration files, use the  or   options.

--buildpkg als emerge Option nutzen
When installing software using, Portage can be asked to create binary packages by using  option:

Es ist ebenfalls möglich Portage dazu zu bringen nur Binärpakete zu erzeugen aber die Software nicht auf dem Live-System zu installieren. Dazu kann die Option  verwendet werden:

Die letztere Herangehensweise macht es erforderlich alle Build-Time Abhängigkeiten zuvor zu installieren.

buildpkg as a Portage Eigenschaft nutzen
Die gewöhnlichste Art um automatisch Binärpakete zu erzeugen wann immer ein Paket von Portage installiert wird, ist die Nutzung der  Eigenschaft. Sie kann auf die folgende Weise in gesetzt werden:

Falls diese Eigenschaft aktiviert ist, wird jedes mal wenn Portage Software installiert, ebenfalls ein Binärpaket erzeugt.

Erzeugung einiger Pakete ausschließen
It is possible to tell Portage not to create binary packages for a select few packages or categories. This is done by passing the  option to emerge:

This could be used for packages that have little to no benefit in having a binary package available. Examples would be the Linux kernel source packages or upstream binary packages (those ending with -bin like ).

Setting up a binary package host
Portage supports a number of protocols for downloading binary packages: FTP, FTPS, HTTP, HTTPS and SSH. This leaves room for many possible binary package host implementations.

There is, however, no "out-of-the-box" method provided by Portage for distributing binary packages. Depending on the desired setup additional software will need to be installed.

Web based binary package host
A common approach for distributing binary packages is to create a web-based binary package host.

Use a web server such as lighttpd and configure it to provide read access to 's PKGDIR location.

Then, on the client systems, configure the PORTAGE_BINHOST variable accordingly:

SSH binary package host
To provide a more authenticated approach for binary packages, one can consider using SSH.

When using SSH, it is possible to use the Portage 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 Portage 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:

The PORTAGE_BINHOST variable could then look like so:

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 file could look like so:

On the clients, the location can then be mounted. An example entry would look like so:

Using binary packages
For binary packages to be usable on other systems they must fulfill some requirements:


 * The client and server architecture and CHOST must match.
 * The CFLAGS and CXXFLAGS variables used to build the binary packages must be compatible with all clients.
 * USE flags for processor specific features (like MMX, SSE,...) have to be carefully selected; all clients need to support them.

Next to these, Portage will check if the binary package is built using the same USE flags as expected on the client. 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 command upon invocation (see Installing binary packages).

On clients, a few configuration changes are needed in order for the binary packages to be used.

Installing binary packages
There are a few options that can be passed on to the command that inform Portage about using binary packages:

In order to automatically use binary package installations, the appropriate option can be added to the EMERGE_DEFAULT_OPTS variable:

There is a Portage feature that automatically implements the equivalent of  without the need for updating the EMERGE_DEFAULT_OPTS variable:

Pulling packages from a binary package host
When using a binary package host, clients need to have the PORTAGE_BINHOST variable set. Otherwise the client will not know where the binary packages are stored which results in Portage being unable to retrieve them.

The PORTAGE_BINHOST variable uses a space-separated list of URIs. This allows administrators to use several binary package servers simultaneously. The URI must always point to the directory in which the file resides.

Reinstalling modified binary packages
Passing the  option to emerge will reinstall every binary that has been rebuilt since the package was installed. This is useful in case rebuilding tools like or  are run on the binary package server.

A related option is. 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  is used otherwise.

Additional client settings
Next to the  feature, Portage also listens to the   feature. This one 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  option:

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 package an application called  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:

For more details please read the Eclean article.

Another tool that can be used is the tool from the  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):

Maintaining the Packages file
Inside the packages directory, a file called exists. 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, updates it when it removes binary packages.

If for some reason binary packages are simply deleted or copied into the packages directory, or the file gets corrupted or deleted, then it must be recreated. This is done using command:

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 or  tool. It takes four arguments:


 * 1) A source directory (the path to the packages directory).
 * 2) A target directory (that must not exist).
 * 3) A URI.
 * 4) A binary package server directory.

The files from the package directory are copied to the target directory. A 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. This URI has to refer to the target directory.

Understanding the binary package format
Binary packages created by Portage have the file name ending with. These files consist of two parts:


 * 1) A  archive containing the files that will be installed on the system.
 * 2) A  archive containing package metadata, the ebuild, and the environment file.

See for a description of the format.

In some tools exists that are able to split or create  and  files.

The following command will split the into a  and an  file:

The file can be examined using the  utility.

To list the contents:

The next command will extract a file called which contains the enabled USE flags for this package:

The PKGDIR layout
The currently used format version 2 has the following layout:

The 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 ) and the category directories only had symbolic links to the binary packages inside the directory.

Unpacking with quickunpkg
Zoobab wrote a simple shell tool named quickunpkg to quickly unpack files.