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