X-Git-Url: https://git.saurik.com/apt.git/blobdiff_plain/b43af876ed0901eabfb7fe93276eb9272cacf22d..3184b4cf2e8e2009ce62b8f66c666ae7da67e378:/doc/apt.conf.5.xml diff --git a/doc/apt.conf.5.xml b/doc/apt.conf.5.xml index e0ce0db40..e37456d73 100644 --- a/doc/apt.conf.5.xml +++ b/doc/apt.conf.5.xml @@ -21,7 +21,7 @@ &apt-email; &apt-product; - 10 December 2008 + 16 January 2010 @@ -37,20 +37,31 @@ 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 directives, possibly - loading even more config files. - + apt.conf is the main configuration file for + the APT suite of tools, but by far not the only place changes to options + can be made. All tools therefore share the configuration files and also + use a common command line parser to provide a uniform environment. + + When an APT tool starts up it will read the configuration files + in the following order: + the file specified by the APT_CONFIG + environment variable (if any) + all files in Dir::Etc::Parts in + alphanumeric ascending order which have no or "conf" + as filename extension and which only contain alphanumeric, + hyphen (-), underscore (_) and period (.) characters - + otherwise they will be silently ignored. + the main configuration file specified by + Dir::Etc::main + the command line options are applied to override the + configuration directives or to load even more configuration files. + + + Syntax 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 APT::Get::Assume-Yes 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. Syntactically the configuration language is modeled after what the ISC tools @@ -58,9 +69,13 @@ // are treated as comments (ignored), as well as all text between /* and */, just like C/C++ comments. 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";. 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: APT { @@ -86,17 +101,41 @@ DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt";}; The names of the configuration items are not case-sensitive. So in the previous example you could use dpkg::pre-install-pkgs. - Two specials are allowed, #include and #clear + Names for the configuration items are optional if a list is defined as it can be see in + the DPkg::Pre-Install-Pkgs 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. + + Two specials are allowed, #include (which is deprecated + and not supported by alternative implementations) 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 part of the configuration tree. The - specified element and all its descendents are erased. + specified element and all its descendants are erased. + (Note that these lines also need to end with a semicolon.) + + The #clear command is the only way to delete a list or a complete scope. + Reopening a scope or the ::-style described below will not + 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. 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 (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. + a trailing :: to the list name. (As you might suspect: The scope syntax can't be used + on the command line.) + + 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 "::" + which acts like every other option with a name. These introduces many problems + including that a user who writes multiple lines in this wrong syntax in + the hope to append to a list will gain the opposite as only the last assignment for this option + "::" 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. The APT Group @@ -111,10 +150,11 @@ DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt";}; Default-Release - Default release to install packages from if more than one - version available. Contains release name, codename or release version. Examples: 'stable', 'testing', 'unstable', 'lenny', 'squeeze', '4.0', '5.0*'. See also &apt-preferences;. + Default release to install packages from if more than one + version available. Contains release name, codename or release version. Examples: 'stable', 'testing', + 'unstable', '&stable-codename;', '&testing-codename;', '4.0', '5.0*'. See also &apt-preferences;. - + Ignore-Hold Ignore Held packages; This global option causes the problem resolver to ignore held packages in its decision making. @@ -128,11 +168,26 @@ DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt";}; Immediate-Configure - 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. + 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, errors out and + refers to this option so the user can deactivate the immediate configuration temporarily 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 was 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 dist-upgrade is run with this option disabled it should be tried to + explicitly install 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. Force-LoopBreak @@ -144,9 +199,20 @@ DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt";}; anything that those packages 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 (in bytes). + Cache-Start, Cache-Grow and Cache-Limit + APT uses since version 0.7.26 a resizable memory mapped cache file to store the 'available' + information. Cache-Start acts as a hint to which size the Cache will grow + and is therefore the amount of memory APT will request at startup. The default value is + 20971520 bytes (~20 MB). Note that these amount of space need to be available for APT + otherwise it will likely fail ungracefully, so for memory restricted devices these value should + be lowered while on systems with a lot of configured sources this might be increased. + Cache-Grow defines in byte with the default of 1048576 (~1 MB) how much + the Cache size will be increased in the event the space defined by Cache-Start + is not enough. These value will be applied again and again until either the cache is big + enough to store all information or the size of the cache reaches the Cache-Limit. + The default of Cache-Limit is 0 which stands for no limit. + If Cache-Grow is set to 0 the automatic grow of the cache is disabled. + Build-Essential @@ -175,10 +241,41 @@ DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt";}; and the URI handlers. + Check-Valid-Until + Security related option defaulting to true as an + expiring validation for a Release file prevents longtime replay attacks + and can e.g. also help users to identify no longer updated mirrors - + but the feature depends on the correctness of the time on the user system. + Archive maintainers are encouraged to create Release files with the + Valid-Until header, but if they don't or a stricter value + is volitional the following Max-ValidTime option can be used. + + + + Max-ValidTime + Seconds the Release file should be considered valid after + it was created. The default is "for ever" (0) if the Release file of the + archive doesn't include a Valid-Until header. + If it does then this date is the default. The date from the Release file or + the date specified by the creation time of the Release file + (Date header) plus the seconds specified with this + options are used to check if the validation of a file has expired by using + the earlier date of the two. Archive specific settings can be made by + appending the label of the archive to the option name. + + + PDiffs Try to download deltas called PDiffs for Packages or Sources files instead of downloading whole ones. True - by default. + by default. + Two sub-options to limit the use of PDiffs are also available: + With FileLimit can be specified how many PDiff files + are downloaded at most to patch a file. SizeLimit + on the other hand is the maximum precentage of the size of all patches + compared to the size of the targeted file. If one of these limits is + exceeded the complete file is downloaded instead of the patches. + Queue-Mode @@ -222,18 +319,30 @@ DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt";}; 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) + 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. + require this are in violation of RFC 2068. + + The used bandwidth can be limited with Acquire::http::Dl-Limit + 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.) + + Acquire::http::User-Agent 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. + https - HTTPS URIs. Cache-control and proxy options are the same as for - http method. - Pipeline-Depth option is not supported yet. + HTTPS URIs. Cache-control, Timeout, AllowRedirect, Dl-Limit and + proxy options are the same as for http method and will also + default to the options from the http method if they are not + explicitly set for https. Pipeline-Depth option is not + supported yet. CaInfo suboption specifies place of file that holds info about trusted certificates. @@ -298,7 +407,7 @@ DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt";}; 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 + 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. @@ -312,17 +421,61 @@ DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt";}; CompressionTypes List of compression types which are understood by the acquire methods. Files like Packages can be available in various compression formats. - This list defines in which order the acquire methods will try to download these files. - Per default bzip2 compressed files will be prefered over - lzma, gzip and uncompressed files. The syntax for - the configuration fileentry is + Per default the acquire methods can decompress bzip2, lzma + and gzip 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: Acquire::CompressionTypes::FileExtension "Methodname"; - e.g. Acquire::CompressionTypes::bz2 "bzip2"; - Note that at runtime the Dir::Bin::Methodname will + Also the Order 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. Acquire::CompressionTypes::Order:: "gz"; can + be used to prefer gzip compressed files over bzip2 and lzma. + If lzma should be preferred over gzip and bzip2 the + configure setting should look like this Acquire::CompressionTypes::Order { "lzma"; "gz"; }; + It is not needed to add bz2 explicit to the list as it will be added automatic. + Note that at run time the Dir::Bin::Methodname will be checked: If this setting exists the method will only be used if this file exists, e.g. for - the bzip2 method above (the inbuilt) setting is Dir::Bin::bzip2 "/bin/bzip2"; - + the bzip2 method (the inbuilt) setting is Dir::Bin::bzip2 "/bin/bzip2"; + 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. + 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. + + + GzipIndexes + + When downloading gzip compressed indexes (Packages, Sources, or + Translations), keep them gzip compressed locally instead of unpacking + them. This saves quite a lot of disk space at the expense of more CPU + requirements when building the local package caches. False by default. + + + Languages + The Languages subsection controls which Translation files are downloaded + and in which order APT tries to display the Description-Translations. APT will try to display the first + available Description in the Language which is listed at first. Languages can be defined with their + short or long Languagecodes. Note that not all archives provide Translation + files for every Language - especially the long Languagecodes are rare, so please + inform you which ones are available before you set here impossible values. + The default list includes "environment" and "en". "environment" has a special meaning here: + It will be replaced at runtime with the languagecodes extracted from the LC_MESSAGES environment variable. + It will also ensure that these codes are not included twice in the list. If LC_MESSAGES + is set to "C" only the Translation-en file (if available) will be used. + To force apt to use no Translation file use the setting Acquire::Languages=none. "none" + is another special meaning code which will stop the search for a fitting Translation file. + This can be used by the system administrator to let APT know that it should download also this files without + actually use them if the environment doesn't specify this languages. So the following example configuration will + result in the order "en, de" in an english and in "de, en" in a german localization. Note that "fr" is downloaded, + but not used if APT is not used in a french localization, in such an environment the order would be "fr, de, en". + Acquire::Languages { "environment"; "de"; "en"; "none"; "fr"; }; + + @@ -374,6 +527,15 @@ DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt";}; will be looked up in /tmp/staging/var/lib/dpkg/status. + + + The Ignore-Files-Silently list can be used to specify + which files APT should silently ignore while parsing the files in the + fragment directories. Per default a file which end with .disabled, + ~, .bak or .dpkg-[a-z]+ + is silently ignored. As seen in the last default value these patterns can use regular + expression syntax. + APT in DSelect @@ -450,6 +612,87 @@ DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt";}; the default is to disable signing and produce all binaries. + + dpkg trigger usage (and related options) + 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. + These options are therefore currently experimental and should not be used in + productive environments. 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. + 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. dpkg --audit. A defensive option combination would be +DPkg::NoTriggers "true"; +PackageManager::Configure "smart"; +DPkg::ConfigurePending "true"; +DPkg::TriggersPending "true"; + + + DPkg::NoTriggers + 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. + + PackageManager::Configure + Valid values are "all", "smart" and "no". + "all" is the default value and causes APT to configure all packages explicit. + The "smart" 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. "no" 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! + + + DPkg::ConfigurePending + If this option is set apt will call dpkg --configure --pending + to let dpkg handle all required configurations and triggers. This option is activated automatic + per default if the previous option is not set to all, 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. + + DPkg::TriggersPending + Useful for smart configuration as a package which has pending + triggers is not considered as installed and dpkg treats them as unpacked + 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. + + PackageManager::UnpackAll + 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 OrderCritical method was unused, so + this method is very experimental and needs further improvements before becoming really useful. + + + OrderList::Score::Immediate + 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 DPkg::TriggersPending 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. + OrderList::Score { + Delete 500; + Essential 200; + Immediate 10; + PreDepends 50; +}; + + + + @@ -833,6 +1076,7 @@ is commented. --> + @@ -844,15 +1088,7 @@ is commented. Files - /etc/apt/apt.conf - APT configuration file. - Configuration Item: Dir::Etc::Main. - - - /etc/apt/apt.conf.d/ - APT configuration file fragments. - Configuration Item: Dir::Etc::Parts. - + &file-aptconf;