Portage API

This page is the beginning of the missing documentation on the Portage Python API.

Introduction

Portage has always had a Python API; however, this API does not appear to be documented at all. This page represents an initial effort to document the API that is available for querying packages, etc.

Portage DBAPI

The API that exists in Portage to query this is called the DBAPI, and the "porttree" -- What is typically stored in /usr/portage, and querying the porttree is what we will examine here, using the interactive python interpreter.

w520 drobbins # python
Python 3.3.5 (default, Sep 21 2015, 23:01:43) 
[GCC 4.9.3] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> portage.root
'/'
>>> import portage
>>> p = portage.db[portage.root]["porttree"].dbapi
>>>

p now contains a reference to the DBAPI associated with the Portage tree associated with the system installed at portage.root, which is typically /usr/portage. We can now perform various queries using this variable.

>>> p.cp_list("sys-apps/portage")
['sys-apps/portage-2.3.6-r9', 'sys-apps/portage-2.3.8']

Above, cp_list takes what is called a "catpkg", which is a reference to a particular ebuild in a repository in "category/packagename" format. We can also get lists of specific available packages, using other functions:

>>> p.match("sys-apps/portage")
['sys-apps/portage-2.3.6-r9', 'sys-apps/portage-2.3.8']
>>> p.match("=sys-apps/portage-2*")
['sys-apps/portage-2.3.6-r9', 'sys-apps/portage-2.3.8']

While at first the match() method looks no different than the cp_list() method, you can see that it accepts any valid dependency atom, which is any individual dependency reference to a particular package. The match() method is actually a shortcut for the more sophisticated xmatch() method -- it matches all visible (non-masked) packages that satisfy the dependency.

Using xmatch(), more sophisticated matching can be performed:

>>> p.xmatch("match-visible", "=sys-apps/portage-2*")
['sys-apps/portage-2.3.6-r9', 'sys-apps/portage-2.3.8']

As you can see, xmatch() with the "match_visible" gives us the identical results as match(). In fact, match() is a shortcut for this particular xmatch() call. However, xmatch() has other matching methods, detailed below:

match mode	Description	Return Type
bestmatch-visible	Find the best (highest) visible (unmasked) match for the dependency.	single string
match-all	Find all matches, masked or unmasked.	list of strings
match-visible	Find all visible (unmasked) matches for the dependency.	list of strings
minimum-all	Find the lowest match for the dependency, ignoring masks.	single string
minimum-visible	Find the lowest match for the dependency, respecting masks.	single string

Querying Package Metadata

Portage is designed to extract and cache a certain set of data from each ebuild, called metadata, and this metadata is queryable and used for dependency calculations, fetching sources, etc. Querying of metadata for a particular ebuild can be performed using the aux_get() DBAPI method:

>>> p.aux_get("sys-apps/portage-2.3.8", ["EAPI", "SRC_URI"])
['5-progress', 'https://www.github.com/funtoo/portage-funtoo/tarball/funtoo-2.3.8 -> portage-funtoo-2.3.8.tar.gz']

The parameters of the aux_get() method are, first, the name of a package in "catpkg-v" format, which is a reference to a specific version of a package in "category/packagename-version(-revision)" format. The second argument is a list or tuple of metadata to return. A list is returned containing the queried metadata in the order specified in the first argument. If necessary, Portage will evaluate the contents of the ebuild to extract and cache this metadata. For porttrees, the following metadata is available (and this may vary by EAPI):

Metadata	Description
DEFINED_PHASES	String containing all phases (see Ebuild Functions) defined in the ebuild, delimited by spaces.
DEPEND	Build dependencies
EAPI	Ebuild API version
HDEPEND	Host Build Dependencies (EAPI 5-hdepend only)
INHERITED	A complete list of eclasses used by this ebuild, directly or indirectly (via eclasses inheriting other eclasses)
IUSE	IUSE variable from ebuild
KEYWORDS	KEYWORDS (masking) setting
LICENSE	LICENSE variable from ebuild
PDEPEND	PDEPEND variable from ebuild
PROPERTIES	PROPERTIES variable from ebuild
PROVIDE	PROVIDE variable from ebuild
RDEPEND	Runtime dependencies
REQUIRED_USE	REQUIRED_USE variable from ebuild
repository	Repository name ("gentoo" in main Gentoo or Funtoo Portage tree)
RESTRICT	RESTRICT variable from ebuild
SLOT	SLOT variable from ebuild