Ubuntu Manpage: sources.list - List of configured APT data sources

NAME

       sources.list - List of configured APT data sources

DESCRIPTION

       The source list /etc/apt/sources.list is designed to support any number of active sources and a variety
       of source media. The file lists one source per line, with the most preferred source listed first. The
       information available from the configured sources is acquired by apt-get update (or by an equivalent
       command from another APT front-end).

       Each line specifying a source starts with type (e.g.  deb-src) followed by options and arguments for this
       type. Individual entries cannot be continued onto a following line. Empty lines are ignored, and a #
       character anywhere on a line marks the remainder of that line as a comment.

SOURCES.LIST.D

       The /etc/apt/sources.list.d directory provides a way to add sources.list entries in separate files. The
       format is the same as for the regular sources.list file. File names need to end with .list and may only
       contain letters (a-z and A-Z), digits (0-9), underscore (_), hyphen (-) and period (.) characters.
       Otherwise APT will print a notice that it has ignored a file, unless that file matches a pattern in the
       Dir::Ignore-Files-Silently configuration list - in which case it will be silently ignored.

THE DEB AND DEB-SRC TYPES

The deb type references a typical two-level Debian archive, distribution/component. The distribution is
generally an archive name like stable or testing or a codename like wheezy or jessie while component is
one of main, contrib or non-free. The deb-src type references a Debian distribution's source code in the
same form as the deb type. A deb-src line is required to fetch source indexes.

The format for a sources.list entry using the deb and deb-src types is:

deb [ options ] uri suite [component1] [component2] [...]

Alternatively a rfc822 style format is also supported:

Types: deb deb-src
URIs: http://example.com
Suites: stable testing
Sections: component1 component2
Description: short
long long long
[option1]: [option1-value]

Types: deb
URIs: http://another.example.com
Suites: experimental
Sections: component1 component2
Enabled: no
Description: short
long long long
[option1]: [option1-value]

The URI for the deb type must specify the base of the Debian distribution, from which APT will find the
information it needs. suite can specify an exact path, in which case the components must be omitted and
suite must end with a slash (/). This is useful for the case when only a particular sub-section of the
archive denoted by the URI is of interest. If suite does not specify an exact path, at least one
component must be present.

suite may also contain a variable, $(ARCH) which expands to the Debian architecture (such as amd64 or
armel) used on the system. This permits architecture-independent sources.list files to be used. In
general this is only of interest when specifying an exact path, APT will automatically generate a URI
with the current architecture otherwise.

In the traditional style sources.list format since only one distribution can be specified per line it may
be necessary to have multiple lines for the same URI, if a subset of all available distributions or
components at that location is desired. APT will sort the URI list after it has generated a complete set
internally, and will collapse multiple references to the same Internet host, for instance, into a single
connection, so that it does not inefficiently establish an FTP connection, close it, do something else,
and then re-establish a connection to that same host. This feature is useful for accessing busy FTP sites
with limits on the number of simultaneous anonymous users. APT also parallelizes connections to different
hosts to more effectively deal with sites with low bandwidth.

options is always optional and needs to be surrounded by square brackets. It can consist of multiple
settings in the form setting=value. Multiple settings are separated by spaces. The following settings are
supported by APT (note however that unsupported settings will be ignored silently):

• arch=arch1,arch2,... can be used to specify for which architectures information should be
downloaded. If this option is not set all architectures defined by the APT::Architectures option will
be downloaded.

• arch+=arch1,arch2,... and arch-=arch1,arch2,... which can be used to add/remove architectures from
the set which will be downloaded.

• trusted=yes can be set to indicate that packages from this source are always authenticated even if
the Release file is not signed or the signature can't be checked. This disables parts of apt-
secure(8) and should therefore only be used in a local and trusted context. trusted=no is the
opposite which handles even correctly authenticated sources as not authenticated.

It is important to list sources in order of preference, with the most preferred source listed first.
Typically this will result in sorting by speed from fastest to slowest (CD-ROM followed by hosts on a
local network, followed by distant Internet hosts, for example).

Some examples:

deb http://ftp.debian.org/debian wheezy main contrib non-free
deb http://security.debian.org/ wheezy/updates main contrib non-free

URI SPECIFICATION

The currently recognized URI types are:

file
The file scheme allows an arbitrary directory in the file system to be considered an archive. This is
useful for NFS mounts and local mirrors or archives.

cdrom
The cdrom scheme allows APT to use a local CD-ROM drive with media swapping. Use the apt-cdrom(8)
program to create cdrom entries in the source list.

http
The http scheme specifies an HTTP server for the archive. If an environment variable http_proxy is
set with the format http://server:port/, the proxy server specified in http_proxy will be used. Users
of authenticated HTTP/1.1 proxies may use a string of the format http://user:pass@server:port/. Note
that this is an insecure method of authentication.

ftp
The ftp scheme specifies an FTP server for the archive. APT's FTP behavior is highly configurable;
for more information see the apt.conf(5) manual page. Please note that an FTP proxy can be specified
by using the ftp_proxy environment variable. It is possible to specify an HTTP proxy (HTTP proxy
servers often understand FTP URLs) using this environment variable and only this environment
variable. Proxies using HTTP specified in the configuration file will be ignored.

copy
The copy scheme is identical to the file scheme except that packages are copied into the cache
directory instead of used directly at their location. This is useful for people using removable media
to copy files around with APT.

rsh, ssh
The rsh/ssh method invokes RSH/SSH to connect to a remote host and access the files as a given user.
Prior configuration of rhosts or RSA keys is recommended. The standard find and dd commands are used
to perform the file transfers from the remote host.

adding more recognizable URI types
APT can be extended with more methods shipped in other optional packages, which should follow the
naming scheme apt-transport-method. For instance, the APT team also maintains the package
apt-transport-https, which provides access methods for HTTPS URIs with features similar to the http
method. Methods for using e.g. debtorrent are also available - see apt-transport-debtorrent(1).

EXAMPLES

       Uses the archive stored locally (or NFS mounted) at /home/jason/debian for stable/main, stable/contrib,
       and stable/non-free.

           deb file:/home/jason/debian stable main contrib non-free

       As above, except this uses the unstable (development) distribution.

           deb file:/home/jason/debian unstable main contrib non-free

       Source line for the above

           deb-src file:/home/jason/debian unstable main contrib non-free

       The first line gets package information for the architectures in APT::Architectures while the second
       always retrieves amd64 and armel.

           deb http://ftp.debian.org/debian wheezy main
           deb [ arch=amd64,armel ] http://ftp.debian.org/debian wheezy main

       Uses HTTP to access the archive at archive.debian.org, and uses only the hamm/main area.

           deb http://archive.debian.org/debian-archive hamm main

       Uses FTP to access the archive at ftp.debian.org, under the debian directory, and uses only the
       wheezy/contrib area.

           deb ftp://ftp.debian.org/debian wheezy contrib

       Uses FTP to access the archive at ftp.debian.org, under the debian directory, and uses only the
       unstable/contrib area. If this line appears as well as the one in the previous example in sources.list a
       single FTP session will be used for both resource lines.

           deb ftp://ftp.debian.org/debian unstable contrib

       Uses HTTP to access the archive at ftp.tlh.debian.org, under the universe directory, and uses only files
       found under unstable/binary-i386 on i386 machines, unstable/binary-amd64 on amd64, and so forth for other
       supported architectures. [Note this example only illustrates how to use the substitution variable;
       official debian archives are not structured like this]

           deb http://ftp.tlh.debian.org/universe unstable/binary-$(ARCH)/

BUGS

       APT bug page[1]. If you wish to report a bug in APT, please see /usr/share/doc/debian/bug-reporting.txt
       or the reportbug(1) command.

AUTHORS

       Jason Gunthorpe

       APT team

NOTES

        1. APT bug page
           http://bugs.debian.org/src:apt