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Diffstat (limited to 'doc/apt.conf.5.xml')
| -rw-r--r-- | doc/apt.conf.5.xml | 274 |
1 files changed, 242 insertions, 32 deletions
diff --git a/doc/apt.conf.5.xml b/doc/apt.conf.5.xml index 1835f2282..d7ad51cfb 100644 --- a/doc/apt.conf.5.xml +++ b/doc/apt.conf.5.xml @@ -21,12 +21,13 @@ &apt-email; &apt-product; <!-- The last update date --> - <date>06 December 2008</date> + <date>18 September 2009</date> </refentryinfo> <refmeta> <refentrytitle>apt.conf</refentrytitle> <manvolnum>5</manvolnum> + <refmiscinfo class="manual">APT</refmiscinfo> </refmeta> <!-- Man page title --> @@ -47,18 +48,23 @@ loading even more config files.</para> <para>The configuration file is organized in a tree with options organized into - functional groups. option specification is given with a double colon + functional groups. Option specification is given with a double colon notation, for instance <literal>APT::Get::Assume-Yes</literal> is an option within - the APT tool group, for the Get tool. options do not inherit from their + the APT tool group, for the Get tool. Options do not inherit from their parent groups.</para> <para>Syntactically the configuration language is modeled after what the ISC tools - such as bind and dhcp use. Lines starting with - <literal>//</literal> are treated as comments (ignored). + such as bind and dhcp use. Lines starting with + <literal>//</literal> are treated as comments (ignored), as well as all text + between <literal>/*</literal> and <literal>*/</literal>, just like C/C++ comments. Each line is of the form - <literal>APT::Get::Assume-Yes "true";</literal> The trailing - semicolon is required and the quotes are optional. A new scope can be - opened with curly braces, like:</para> + <literal>APT::Get::Assume-Yes "true";</literal>. The trailing + semicolon and the quotes are required. The value must be on one line, and + there is no kind of string concatenation. It must not include inside quotes. + The behavior of the backslash "\" and escaped characters inside a value is + undefined and it should not be used. An option name may include + alphanumerical characters and the "/-:._+" characters. A new scope can + be opened with curly braces, like:</para> <informalexample><programlisting> APT { @@ -70,7 +76,7 @@ APT { </programlisting></informalexample> <para>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 + opening a scope and including a single string enclosed in quotes followed by a semicolon. Multiple entries can be included, each separated by a semicolon.</para> <informalexample><programlisting> @@ -84,16 +90,41 @@ DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt";}; <para>The names of the configuration items are not case-sensitive. So in the previous example you could use <literal>dpkg::pre-install-pkgs</literal>.</para> - <para>Two specials are allowed, <literal>#include</literal> and <literal>#clear</literal> + <para>Names for the configuration items are optional if a list is defined as it can be see in + the <literal>DPkg::Pre-Install-Pkgs</literal> example above. If you don't specify a name a + new entry will simply add a new option to the list. If you specify a name you can override + the option as every other option by reassigning a new value to the option.</para> + + <para>Two specials are allowed, <literal>#include</literal> (which is deprecated + and not supported by alternative implementations) and <literal>#clear</literal>: <literal>#include</literal> will include the given file, unless the filename ends in a slash, then the whole directory is included. - <literal>#clear</literal> is used to erase a list of names.</para> + <literal>#clear</literal> is used to erase a part of the configuration tree. The + specified element and all its descendants are erased. + (Note that these lines also need to end with a semicolon.)</para> + + <para>The #clear command is the only way to delete a list or a complete scope. + Reopening a scope or the ::-style described below will <emphasis>not</emphasis> + override previously written entries. Only options can be overridden by addressing a new + value to it - lists and scopes can't be overridden, only cleared.</para> <para>All of the APT tools take a -o option which allows an arbitrary configuration directive to be specified on the command line. The syntax is a full option name (<literal>APT::Get::Assume-Yes</literal> 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.</para> + a trailing :: to the list name. (As you might suspect: The scope syntax can't be used + on the command line.)</para> + + <para>Note that you can use :: only for appending one item per line to a list and + that you should not use it in combination with the scope syntax. + (The scope syntax implicit insert ::) Using both syntaxes together will trigger a bug + which some users unfortunately relay on: An option with the unusual name "<literal>::</literal>" + which acts like every other option with a name. These introduces many problems + including that a user who writes multiple lines in this <emphasis>wrong</emphasis> syntax in + the hope to append to a list will gain the opposite as only the last assignment for this option + "<literal>::</literal>" will be used. Upcoming APT versions will raise errors and + will stop working if they encounter this misuse, so please correct such statements now + as long as APT doesn't complain explicit about them.</para> </refsect1> <refsect1><title>The APT Group</title> @@ -109,7 +140,7 @@ DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt";}; <varlistentry><term>Default-Release</term> <listitem><para>Default release to install packages from if more than one - version available. Contains release name or release version. Examples: 'stable', 'testing', 'unstable', '4.0', '5.0*'. Release codenames ('etch', 'lenny' etc.) are not allowed now. See also &apt-preferences;.</para></listitem> + version available. Contains release name, codename or release version. Examples: 'stable', 'testing', 'unstable', 'lenny', 'squeeze', '4.0', '5.0*'. See also &apt-preferences;.</para></listitem> </varlistentry> <varlistentry><term>Ignore-Hold</term> @@ -125,11 +156,26 @@ DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt";}; </varlistentry> <varlistentry><term>Immediate-Configure</term> - <listitem><para>Disable Immediate Configuration; This dangerous option disables some - of APT's ordering code to cause it to make fewer dpkg calls. Doing - so may be necessary on some extremely slow single user systems but - is very dangerous and may cause package install scripts to fail or worse. - Use at your own risk.</para></listitem> + <listitem><para>Defaults to on which will cause APT to install essential and important packages + as fast as possible in the install/upgrade operation. This is done to limit the effect of a failing + &dpkg; call: If this option is disabled APT does treat an important package in the same way as + an extra package: Between the unpacking of the important package A and his configuration can then + be many other unpack or configuration calls, e.g. for package B which has no relation to A, but + causes the dpkg call to fail (e.g. because maintainer script of package B generates an error) which results + in a system state in which package A is unpacked but unconfigured - each package depending on A is now no + longer guaranteed to work as their dependency on A is not longer satisfied. The immediate configuration marker + is also applied to all dependencies which can generate a problem if the dependencies e.g. form a circle + as a dependency with the immediate flag is comparable with a Pre-Dependency. So in theory it is possible + that APT encounters a situation in which it is unable to perform immediate configuration, error out and + refers to this option so the user can deactivate the immediate configuration temporary to be able to perform + an install/upgrade again. Note the use of the word "theory" here as this problem was only encountered by now + in real world a few times in non-stable distribution versions and caused by wrong dependencies of the package + in question or by a system in an already broken state, so you should not blindly disable this option as + the mentioned scenario above is not the only problem immediate configuration can help to prevent in the first place. + Before a big operation like <literal>dist-upgrade</literal> is run with this option disabled it should be tried to + explicitly <literal>install</literal> the package APT is unable to configure immediately, but please make sure to + report your problem also to your distribution and to the APT team with the buglink below so they can work on + improving or correcting the upgrade process.</para></listitem> </varlistentry> <varlistentry><term>Force-LoopBreak</term> @@ -173,7 +219,7 @@ DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt";}; <variablelist> <varlistentry><term>PDiffs</term> - <listitem><para>Try do download deltas called <literal>PDiffs</literal> for + <listitem><para>Try to download deltas called <literal>PDiffs</literal> for Packages or Sources files instead of downloading whole ones. True by default.</para></listitem> </varlistentry> @@ -201,8 +247,9 @@ DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt";}; standard form of <literal>http://[[user][:pass]@]host[:port]/</literal>. Per host proxies can also be specified by using the form <literal>http::Proxy::<host></literal> with the special keyword <literal>DIRECT</literal> - meaning to use no proxies. The <envar>http_proxy</envar> environment variable - will override all settings.</para> + meaning to use no proxies. If no one of the above settings is specified, + <envar>http_proxy</envar> environment variable + will be used.</para> <para>Three settings are provided for cache control with HTTP/1.1 compliant proxy caches. <literal>No-Cache</literal> tells the proxy to not use its cached @@ -218,18 +265,30 @@ DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt";}; this applies to all things including connection timeout and data timeout.</para> <para>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) + remote server is not RFC conforming or buggy (such as Squid 2.0.2). <literal>Acquire::http::Pipeline-Depth</literal> 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.</para></listitem> + require this are in violation of RFC 2068.</para> + + <para>The used bandwidth can be limited with <literal>Acquire::http::Dl-Limit</literal> + which accepts integer values in kilobyte. The default value is 0 which deactivates + the limit and tries uses as much as possible of the bandwidth (Note that this option implicit + deactivates the download from multiple servers at the same time.)</para> + + <para><literal>Acquire::http::User-Agent</literal> can be used to set a different + User-Agent for the http download method as some proxies allow access for clients + only if the client uses a known identifier.</para> + </listitem> </varlistentry> <varlistentry><term>https</term> - <listitem><para>HTTPS URIs. Cache-control and proxy options are the same as for - <literal>http</literal> method. - <literal>Pipeline-Depth</literal> option is not supported yet.</para> + <listitem><para>HTTPS URIs. Cache-control, Timeout, AllowRedirect, Dl-Limit and + proxy options are the same as for <literal>http</literal> method and will also + default to the options from the <literal>http</literal> method if they are not + explicitly set for https. <literal>Pipeline-Depth</literal> option is not + supported yet.</para> <para><literal>CaInfo</literal> suboption specifies place of file that holds info about trusted certificates. @@ -250,9 +309,13 @@ DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt";}; </para></listitem></varlistentry> <varlistentry><term>ftp</term> - <listitem><para>FTP URIs; ftp::Proxy is the default proxy server to use. It is in the - standard form of <literal>ftp://[[user][:pass]@]host[:port]/</literal> and is - overridden by the <envar>ftp_proxy</envar> environment variable. To use a ftp + <listitem><para>FTP URIs; ftp::Proxy is the default ftp proxy to use. It is in the + standard form of <literal>ftp://[[user][:pass]@]host[:port]/</literal>. Per + host proxies can also be specified by using the form + <literal>ftp::Proxy::<host></literal> with the special keyword <literal>DIRECT</literal> + meaning to use no proxies. If no one of the above settings is specified, + <envar>ftp_proxy</envar> environment variable + will be used. To use a ftp proxy you will have to set the <literal>ftp::ProxyLogin</literal> script in the configuration file. This entry specifies the commands to send to tell the proxy server what to connect to. Please see @@ -290,7 +353,7 @@ DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt";}; as specified in <filename>/etc/fstab</filename>. 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 <literallayout>"/cdrom/"::Mount "foo";</literallayout> within + is to put <literallayout>/cdrom/::Mount "foo";</literallayout> within the cdrom block. It is important to have the trailing slash. Unmount commands can be specified using UMount.</para></listitem> </varlistentry> @@ -301,6 +364,34 @@ DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt";}; </para></listitem> </varlistentry> + <varlistentry><term>CompressionTypes</term> + <listitem><para>List of compression types which are understood by the acquire methods. + Files like <filename>Packages</filename> can be available in various compression formats. + Per default the acquire methods can decompress <command>bzip2</command>, <command>lzma</command> + and <command>gzip</command> compressed files, with this setting more formats can be added + on the fly or the used method can be changed. The syntax for this is: + <synopsis>Acquire::CompressionTypes::<replaceable>FileExtension</replaceable> "<replaceable>Methodname</replaceable>";</synopsis> + </para><para>Also the <literal>Order</literal> subgroup can be used to define in which order + the acquire system will try to download the compressed files. The acquire system will try the first + and proceed with the next compression type in this list on error, so to prefer one over the other type + simple add the preferred type at first - not already added default types will be added at run time + to the end of the list, so e.g. <synopsis>Acquire::CompressionTypes::Order:: "gz";</synopsis> can + be used to prefer <command>gzip</command> compressed files over <command>bzip2</command> and <command>lzma</command>. + If <command>lzma</command> should be preferred over <command>gzip</command> and <command>bzip2</command> the + configure setting should look like this <synopsis>Acquire::CompressionTypes::Order { "lzma"; "gz"; };</synopsis> + It is not needed to add <literal>bz2</literal> explicit to the list as it will be added automatic.</para> + <para>Note that at run time the <literal>Dir::Bin::<replaceable>Methodname</replaceable></literal> will + be checked: If this setting exists the method will only be used if this file exists, e.g. for + the bzip2 method (the inbuilt) setting is <literallayout>Dir::Bin::bzip2 "/bin/bzip2";</literallayout> + Note also that list entries specified on the command line will be added at the end of the list + specified in the configuration files, but before the default entries. To prefer a type in this case + over the ones specified in in the configuration files you can set the option direct - not in list style. + This will not override the defined list, it will only prefix the list with this type.</para> + <para>While it is possible to add an empty compression type to the order list, but APT in its current + version doesn't understand it correctly and will display many warnings about not downloaded files - + these warnings are most of the time false negatives. Future versions will maybe include a way to + really prefer uncompressed files to support the usage of local mirrors.</para></listitem> + </varlistentry> </variablelist> </para> </refsect1> @@ -335,6 +426,7 @@ DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt";}; <para>Binary programs are pointed to by <literal>Dir::Bin</literal>. <literal>Dir::Bin::Methods</literal> specifies the location of the method handlers and <literal>gzip</literal>, + <literal>bzip2</literal>, <literal>lzma</literal>, <literal>dpkg</literal>, <literal>apt-get</literal> <literal>dpkg-source</literal> <literal>dpkg-buildpackage</literal> and <literal>apt-cache</literal> specify the location of the respective programs.</para> @@ -427,6 +519,87 @@ DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt";}; the default is to disable signing and produce all binaries.</para></listitem> </varlistentry> </variablelist> + + <refsect2><title>dpkg trigger usage (and related options)</title> + <para>APT can call dpkg in a way so it can make aggressive use of triggers over + multiply calls of dpkg. Without further options dpkg will use triggers only in between his + own run. Activating these options can therefore decrease the time needed to perform the + install / upgrade. Note that it is intended to activate these options per default in the + future, but as it changes the way APT calling dpkg drastically it needs a lot more testing. + <emphasis>These options are therefore currently experimental and should not be used in + productive environments.</emphasis> Also it breaks the progress reporting so all frontends will + currently stay around half (or more) of the time in the 100% state while it actually configures + all packages.</para> + <para>Note that it is not guaranteed that APT will support these options or that these options will + not cause (big) trouble in the future. If you have understand the current risks and problems with + these options, but are brave enough to help testing them create a new configuration file and test a + combination of options. Please report any bugs, problems and improvements you encounter and make sure + to note which options you have used in your reports. Asking dpkg for help could also be useful for + debugging proposes, see e.g. <command>dpkg --audit</command>. A defensive option combination would be +<literallayout>DPkg::NoTriggers "true"; +PackageManager::Configure "smart"; +DPkg::ConfigurePending "true"; +DPkg::TriggersPending "true";</literallayout></para> + + <variablelist> + <varlistentry><term>DPkg::NoTriggers</term> + <listitem><para>Add the no triggers flag to all dpkg calls (except the ConfigurePending call). + See &dpkg; if you are interested in what this actually means. In short: dpkg will not run the + triggers when this flag is present unless it is explicitly called to do so in an extra call. + Note that this option exists (undocumented) also in older apt versions with a slightly different + meaning: Previously these option only append --no-triggers to the configure calls to dpkg - + now apt will add these flag also to the unpack and remove calls.</para></listitem> + </varlistentry> + <varlistentry><term>PackageManager::Configure</term> + <listitem><para>Valid values are "<literal>all</literal>", "<literal>smart</literal>" and "<literal>no</literal>". + "<literal>all</literal>" is the default value and causes APT to configure all packages explicit. + The "<literal>smart</literal>" way is it to configure only packages which need to be configured before + another package can be unpacked (Pre-Depends) and let the rest configure by dpkg with a call generated + by the next option. "<literal>no</literal>" on the other hand will not configure anything and totally + rely on dpkg for configuration (which will at the moment fail if a Pre-Depends is encountered). + Setting this option to another than the all value will implicitly activate also the next option per + default as otherwise the system could end in an unconfigured status which could be unbootable! + </para></listitem> + </varlistentry> + <varlistentry><term>DPkg::ConfigurePending</term> + <listitem><para>If this option is set apt will call <command>dpkg --configure --pending</command> + to let dpkg handle all required configurations and triggers. This option is activated automatic + per default if the previous option is not set to <literal>all</literal>, but deactivating could be useful + if you want to run APT multiple times in a row - e.g. in an installer. In these sceneries you could + deactivate this option in all but the last run.</para></listitem> + </varlistentry> + <varlistentry><term>DPkg::TriggersPending</term> + <listitem><para>Useful for <literal>smart</literal> configuration as a package which has pending + triggers is not considered as <literal>installed</literal> and dpkg treats them as <literal>unpacked</literal> + currently which is a dealbreaker for Pre-Dependencies (see debbugs #526774). Note that this will + process all triggers, not only the triggers needed to configure this package.</para></listitem> + </varlistentry> + <varlistentry><term>PackageManager::UnpackAll</term> + <listitem><para>As the configuration can be deferred to be done at the end by dpkg it can be + tried to order the unpack series only by critical needs, e.g. by Pre-Depends. Default is true + and therefore the "old" method of ordering in various steps by everything. While both method + were present in earlier APT versions the <literal>OrderCritical</literal> method was unused, so + this method is very experimental and needs further improvements before becoming really useful. + </para></listitem> + </varlistentry> + <varlistentry><term>OrderList::Score::Immediate</term> + <listitem><para>Essential packages (and there dependencies) should be configured immediately + after unpacking. It will be a good idea to do this quite early in the upgrade process as these + these configure calls require currently also <literal>DPkg::TriggersPending</literal> which + will run quite a few triggers (which maybe not needed). Essentials get per default a high score + but the immediate flag is relatively low (a package which has a Pre-Depends is higher rated). + These option and the others in the same group can be used to change the scoring. The following + example shows the settings with there default values. + <literallayout>OrderList::Score { + Delete 500; + Essential 200; + Immediate 10; + PreDepends 50; +};</literallayout> + </para></listitem> + </varlistentry> + </variablelist> + </refsect2> </refsect1> <refsect1> @@ -678,12 +851,33 @@ DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt";}; </listitem> </varlistentry> + <varlistentry> + <term><literal>Debug::pkgDepCache::Marker</literal></term> + <listitem> + <para> + Generate debug messages describing which package is marked + as keep/install/remove while the ProblemResolver does his work. + Each addition or deletion may trigger additional actions; + they are shown indented two additional space under the original entry. + The format for each line is <literal>MarkKeep</literal>, + <literal>MarkDelete</literal> or <literal>MarkInstall</literal> followed by + <literal>package-name <a.b.c -> d.e.f | x.y.z> (section)</literal> + where <literal>a.b.c</literal> is the current version of the package, + <literal>d.e.f</literal> is the version considered for installation and + <literal>x.y.z</literal> is a newer version, but not considered for installation + (because of a low pin score). The later two can be omitted if there is none or if + it is the same version as the installed. + <literal>section</literal> is the name of the section the package appears in. + </para> + </listitem> + </varlistentry> + <!-- Question: why doesn't this do anything? The code says it should. --> <varlistentry> <term><literal>Debug::pkgInitConfig</literal></term> <listitem> <para> - Dump the default configuration to standard output on + Dump the default configuration to standard error on startup. </para> </listitem> @@ -756,6 +950,17 @@ DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt";}; </varlistentry> <varlistentry> + <term><literal>Debug::pkgProblemResolver::ShowScores</literal></term> + <listitem> + <para> + Display a list of all installed packages with their calculated score + used by the pkgProblemResolver. The description of the package + is the same as described in <literal>Debug::pkgDepCache::Marker</literal> + </para> + </listitem> + </varlistentry> + + <varlistentry> <term><literal>Debug::sourceList</literal></term> <listitem> @@ -766,6 +971,8 @@ DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt";}; </listitem> </varlistentry> +<!-- 2009/07/11 Currently used nowhere. The corresponding code +is commented. <varlistentry> <term><literal>Debug::Vendor</literal></term> @@ -775,6 +982,7 @@ DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt";}; </para> </listitem> </varlistentry> +--> </variablelist> </refsect1> @@ -785,7 +993,9 @@ DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt";}; </refsect1> <refsect1><title>Files</title> - <para><filename>/etc/apt/apt.conf</filename></para> + <variablelist> + &file-aptconf; + </variablelist> </refsect1> <refsect1><title>See Also</title> |