APT.CONF(5) apt.conf APT.CONF(5)NAME
apt.conf - Configuration file for APT
DESCRIPTION
apt.conf is the main configuration file for the APT suite of tools, all
tools make use of the configuration file and a common command-line
parser to provide a uniform environment. When an APT tool starts up it
will read the configuration specified by the APT_CONFIG environment
variable (if any) and then read the files in Dir::Etc::Parts then read
the main configuration file specified by Dir::Etc::main then finally
apply the command-line options to override the configuration direc‐
tives, possibly loading even more config files.
The configuration file is organized in a tree with options organized
into functional groups. Option specification is given with a double
colon notation, for instance APT::Get::Assume-Yes is an option within
the APT tool group, for the Get tool. Options do not inherit from their
parent groups.
Syntacticly, the configuration language is modeled after what the ISC
tools such as bind and dhcp use. Lines starting with // are treated as
comments (ignored). Each line is of the form:
APT::Get::Assume-Yes "true";
The trailing semicolon is required and the quotes are optional. A new
scope can be opened with curly braces, like:
APT {
Get {
Assume-Yes "true";
Fix-Broken "true";
};
};
with newlines placed to make it more readable. Lists can be created by
opening a scope and including a single word enclosed in quotes followed
by a semicolon. Multiple entries can be included, each separated by a
semicolon:
RPM::Allow-Duplicated {"kernel"; "kernel-smp";};
In general the sample configuration file in /usr/share/doc/apt/exam‐
ples/apt.conf and /usr/share/doc/apt/examples/configure-index.gz are
good guides for how it should look.
Two specials are allowed, #include and #clear. #include will include
the given file, unless the filename ends in a slash, then the whole
directory is included. #clear is used to erase a list of names.
All of the APT tools take a -o option which allows an arbitrary config‐
uration directive to be specified on the command line. The syntax is a
full option name (APT::Get::Assume-Yes for instance) followed by an
equals sign (=) then the new value of the option. Lists can be appended
too by adding a trailing :: to the list name.
THE APT GROUP
This group of options controls general APT behavior as well as holding
the options for all of the tools.
Architecture
System Architecture. Sets the architecture to use when fetching
files and parsing package lists. The internal default is the
architecture apt was compiled for.
Ignore-Hold
Ignore Held packages. This global option causes the problem
resolver to ignore held packages in its decision making.
Clean-Installed
Defaults to on. When turned on the autoclean feature will
remove any packages which can no longer be downloaded from the
cache. If turned off, then packages that are locally installed
are also excluded from cleaning - but note that APT provides no
direct means to reinstall them.
Force-LoopBreak
Never Enable this option unless you really know what you are
doing. It permits APT to temporarily remove an essential package
to break a Conflicts/Conflicts or Conflicts/Pre-Depend loop
between two essential packages. SUCH A LOOP SHOULD NEVER EXIST
AND IS A GRAVE BUG. This option will work if the essential pack‐
ages are not gzip, libc, rpm, bash or anything that those pack‐
ages depend on.
Cache-Limit
APT uses a fixed size memory mapped cache file to store the
'available' information. This sets the size of that cache.
Build-Essential
Defines which package(s) are considered essential build depen‐
dencies.
Get The Get subsection controls the apt-get(8) tool, please see its
documentation for more information about the options here.
Cache The Cache subsection controls the apt-cache(8) tool, please see
its documentation for more information about the options here.
CDROM The CDROM subsection controls the apt-cdrom(8) tool, please see
its documentation for more information about the options here.
THE ACQUIRE GROUP
The Acquire group of options controls the download of packages and the
URI handlers.
Queue-Mode
Queuing mode. Queue-Mode can be one of host or access which
determines how APT parallelizes outgoing connections. host means
that one connection per target host will be opened, access means
that one connection per URI type will be opened.
Retries
Number of retries to perform. If this is non-zero APT will retry
failed files the given number of times.
Source-Symlinks
Use symlinks for source archives. If set to true then source ar‐
chives will be symlinked when possible instead of copying. True
is the default
http HTTP URIs. http::Proxy is the default http proxy to use. It is
in the standard form of http://[[user][:pass]@]host[:port]/.
Per-host proxies can also be specified by using the form
http::Proxy::<host> with the special keyword DIRECT meaning to
use no proxies. The "http_proxy" environment variable will over‐
ride all settings.
Three settings are provided for cache control with HTTP/1.1 com‐
pliant proxy caches. No-Cache tells the proxy to not use its
cached response under any circumstances, Max-Age is sent only
for index files and tells the cache to refresh its object if it
is older than the given number of seconds; the default is 1 day.
No-Store specifies that the cache should never store this
request, it is only set for archive files. This may be useful to
prevent polluting a proxy cache with very large .rpm files.
Note: Squid 2.0.2 does not support any of these options.
The option timeout sets the timeout timer used by the method,
this applies to all things including connection timeout and data
timeout.
One setting is provided to control the pipeline depth in cases
where the remote server is not RFC conforming or buggy (such as
Squid 2.0.2) Acquire::http::Pipeline-Depth can be a value from 0
to 5 indicating how many outstanding requests APT should send. A
value of zero MUST be specified if the remote host does not
properly linger on TCP connections - otherwise data corruption
will occur. Hosts which require this are in violation of RFC
2068.
ftp FTP URIs. ftp::Proxy is the default proxy server to use. It is
in the standard form of ftp://[[user][:pass]@]host[:port]/ and
is overridden by the "ftp_proxy" environment variable. To use a
ftp proxy you will have to set the ftp::ProxyLogin script in the
configuration file. This entry specifies the commands to send to
tell the proxy server what to connect to. Please see
/usr/share/doc/apt/examples/configure-index.gz for an example of
how to do this. The subsitution variables available are
$(PROXY_USER), $(PROXY_PASS), $(SITE_USER), $(SITE_PASS),
$(SITE), and $(SITE_PORT). Each is taken from it's respective
URI component.
The option timeout sets the timeout timer used by the method,
this applies to all things including connection timeout and data
timeout.
Several settings are provided to control passive mode. Generally
it is safe to leave passive mode on, it works in nearly every
environment. However some situations require that passive mode
be disabled and port mode ftp used instead. This can be done
globally, for connections that go through a proxy or for a spe‐
cific host (See the sample config file for examples).
It is possible to proxy FTP over HTTP by setting the "ftp_proxy"
environment variable to a http url - see the discussion of the
http method above for syntax. You cannot set this in the config‐
uration file and it is not recommended to use FTP over HTTP due
to its low efficiency.
The setting ForceExtended controls the use of RFC2428 EPSV and
EPRT commands. The defaut is false, which means these commands
are only used if the control connection is IPv6. Setting this to
true forces their use even on IPv4 connections. Note that most
FTP servers do not support RFC2428.
cdrom CDROM URIs. The only setting for CDROM URIs is the mount point,
cdrom::Mount which must be the mount point for the CDROM drive
as specified in /etc/fstab. It is possible to provide alternate
mount and unmount commands if your mount point cannot be listed
in the fstab (such as an SMB mount and old mount packages). The
syntax is to put:
"/cdrom/"::Mount "foo";
within the cdrom block. It is important to have the trailing
slash. Unmount commands can be specified using UMount.
DIRECTORIES
The Dir::State section has directories that pertain to local state
information. lists is the directory to place downloaded package lists
in. preferences is the name of the APT preferences file. Dir::State
contains the default directory to prefix on all sub items if they do
not start with / or ./.
Dir::Cache contains locations pertaining to local cache information,
such as the two package caches srcpkgcache and pkgcache as well as the
location to place downloaded archives, Dir::Cache::archives. Genera‐
tion of caches can be turned off by setting their names to be blank.
This will slow down startup but save disk space. It is probably pref‐
ered to turn off the pkgcache rather than the srcpkgcache. Like
Dir::State the default directory is contained in Dir::Cache.
Dir::Etc contains the location of configuration files, sourcelist gives
the location of the sourcelist and main is the default configuration
file (setting has no effect, unless it is done from the config file
specified by the "APT_CONFIG" environment variable).
The Dir::Parts setting reads in all the config fragments in lexical
order from the directory specified. After this is done then the main
config file is loaded.
Binary programs are pointed to by Dir::Bin. Dir::Bin::Methods specifies
the location of the method handlers while gzip, rpm, apt-get, rpmbuild
and apt-cache specify the location of their respective programs.
HOW APT CALLS RPM
Several configuration directives control how APT invokes rpm(8). These
are in the RPM section.
Options
This is a list of options to pass to rpm(8) for all install,
upgrade and remove operations. The options must be specified
using the list notation and each list item is passed as a single
argument.
Install-Options
This is a list of options to pass to rpm(8) during install and
upgrade operations. The options must be specified using the list
notation and each list item is passed as a single argument.
Erase-Options
This is a list of options to pass to rpm(8) during remove opera‐
tions. The options must be specified using the list notation
and each list item is passed as a single argument.
Pre-Invoke, Post-Invoke
This is a list of shell commands to run before/after invoking
rpm(8). Like Options this must be specified in list notation.
The commands are invoked in order using /bin/sh; should any fail
APT will abort.
Pre-Install-Pkgs
This is a list of shell commands to run before invoking rpm(8).
Like Options this must be specified in list notation. The com‐
mands are invoked in order using /bin/sh; should any fail APT
will abort. APT will pass to the commands on standard input the
filenames of all .rpm files it is going to install, one per
line.
Version 2 of this protocol dumps more information, including the
protocol version, the APT configuration space and the packages,
files and versions being changed. Version 2 is enabled by set‐
ting DPkg::Tools::Options::cmd::Version to 2. cmd is a command
given to Pre-Install-Pkgs.
Run-Directory
APT chdirs to this directory before invoking rpm(8), the default
is /.
Build-Options
These options are passed to rpmbuild(8) when compiling packages.
DEBUG OPTIONS
Most of the options in the debug section are not interesting to the
normal user, however Debug::pkgProblemResolver shows interesting output
about the decisions apt-get dist-upgrade makes. Debug::NoLocking dis‐
ables file locking so APT can do some operations as non-root and
Debug::pkgRPMPM will print out the command-line for each rpm(8) invoca‐
tion. Debug::IdentCdrom will disable the inclusion of statfs data in
CDROM IDs.
EXAMPLES
/usr/share/doc/apt/examples/configure-index.gz contains a sample con‐
figuration file showing the default values for all possible options.
FILES
/etc/apt/apt.conf
SEE ALSOapt-cache(8), apt-config(8), apt_preferences(5).
BUGS
Reporting bugs in APT-RPM is best done in the APT-RPM mailinglist at
http://apt-rpm.org/mailinglist.shtml.
AUTHOR
Maintainer and contributor information can be found in the credits page
http://apt-rpm.org/about.shtml of APT-RPM.
APT-RPM 14 Jun 2006 APT.CONF(5)