&apt-email;
&apt-product;
<!-- The last update date -->
- <date>10 December 2008</date>
+ <date>18 September 2009</date>
</refentryinfo>
<refmeta>
<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> 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 part of the configuration tree. The
- specified element and all its descendents are erased.</para>
+ 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>
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></listitem>
</varlistentry>
<varlistentry><term>https</term>
<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.
- This list defines in which order the acquire methods will try to download these files.
- Per default <command>bzip2</command> compressed files will be prefered over
- <command>lzma</command>, <command>gzip</command> and uncompressed files. The syntax for
- the configuration fileentry is
+ 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>
- e.g. <synopsis>Acquire::CompressionTypes::bz2 "bzip2";</synopsis>
- Note that at runtime the <literal>Dir::Bin::<replaceable>Methodname</replaceable></literal> will
+ </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 above (the inbuilt) setting is <literallayout>Dir::Bin::bzip2 "/bin/bzip2";</literallayout>
- </para></listitem>
+ 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>
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 (expect the ConfigurePending call).
+ See &dpkg; if you are interested in what this actually means. In short: dpkg will not run the
+ triggers then this flag is present unless it is explicit 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
+ relay 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 implicit 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 this 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>
<refsect1><title>Files</title>
<variablelist>
- <varlistentry><term><filename>/etc/apt/apt.conf</filename></term>
- <listitem><para>APT configuration file.
- Configuration Item: <literal>Dir::Etc::Main</literal>.</para></listitem>
- </varlistentry>
-
- <varlistentry><term><filename>/etc/apt/apt.conf.d/</filename></term>
- <listitem><para>APT configuration file fragments.
- Configuration Item: <literal>Dir::Etc::Parts</literal>.</para></listitem>
- </varlistentry>
+ &file-aptconf;
</variablelist>
</refsect1>
projects / apt.git / blobdiff