&apt-email;
&apt-product;
<!-- The last update date -->
- <date>2015-12-14T00:00:00Z</date>
+ <date>2016-09-20T00:00:00Z</date>
</refentryinfo>
<refmeta>
</para></listitem>
</varlistentry>
+ <varlistentry><term><option>Compressor</option></term>
+ <listitem><para>
+ This scope defines which compression formats are supported, how compression
+ and decompression can be performed if support for this format isn't built
+ into apt directly and a cost-value indicating how costly it is to compress
+ something in this format. As an example the following configuration stanza
+ would allow apt to download and uncompress as well as create and store
+ files with the low-cost <literal>.reversed</literal> file extension which
+ it will pass to the command <command>rev</command> without additional
+ commandline parameters for compression and uncompression:
+<informalexample><programlisting>
+APT::Compressor::rev {
+ Name "rev";
+ Extension ".reversed";
+ Binary "rev";
+ CompressArg {};
+ UncompressArg {};
+ Cost "10";
+};
+</programlisting></informalexample>
+ </para></listitem>
+ </varlistentry>
+
<varlistentry><term><option>Build-Profiles</option></term>
<listitem><para>
List of all build profiles enabled for build-dependency resolution,
only if the client uses a known identifier.</para>
<para><literal>Acquire::http::Proxy-Auto-Detect</literal> can be used to
- specify an external command to discover the http proxy to use. Apt expects
- the command to output the proxy on stdout in the style
- <literal>http://proxy:port/</literal>. This will override the
- generic <literal>Acquire::http::Proxy</literal> but not any specific
- host proxy configuration set via
- <literal>Acquire::http::Proxy::$HOST</literal>.
+ specify an external command to discover the http proxy to use. The first
+ and only parameter is an URI denoting the host to be contacted to allow
+ for host-specific configuration. APT expects the command to output the
+ proxy on stdout as a single line in the style <literal>http://proxy:port/</literal>
+ or the word <literal>DIRECT</literal> if no proxy should be used. No output
+ indicates that the generic proxy settings should be used.
+
+ Note that auto-detection will not be used for a host if a host-specific proxy
+ configuration is already set via <literal>Acquire::http::Proxy::<replaceable>HOST</replaceable></literal>.
See the &squid-deb-proxy-client; package for an example implementation that
- uses avahi. This option takes precedence over the legacy option name
+ uses avahi.
+
+ This option takes precedence over the legacy option name
<literal>ProxyAutoDetect</literal>.
</para>
<varlistentry><term><option>CompressionTypes</option></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.
- By 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:
+ By default the acquire methods can decompress and recompress many common formats like <command>xz</command> and
+ <command>gzip</command>; with this scope the supported formats can be queried, modified
+ as well as support for more formats added (see also <option>APT::Compressor</option>). 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
- simply add the preferred type first - default types not already added will be implicitly appended
+ simply add the preferred type first - types not already added will be implicitly appended
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>
+ be used to prefer <command>gzip</command> compressed files over all other compression formats.
+ If <command>xz</command> should be preferred over <command>gzip</command> and <command>bzip2</command> the
+ configure setting should look like this: <synopsis>Acquire::CompressionTypes::Order { "xz"; "gz"; };</synopsis>
It is not needed to add <literal>bz2</literal> to the list explicitly as it will be added automatically.</para>
<para>Note that the
<literal>Dir::Bin::<replaceable>Methodname</replaceable></literal>
- will be checked at run time. If this option has been set, the
- method will only be used if this file exists; e.g. for the
- <literal>bzip2</literal> method (the inbuilt) setting is:
- <literallayout>Dir::Bin::bzip2 "/bin/bzip2";</literallayout>
+ will be checked at run time. If this option has been set and support for
+ this format isn't directly built into apt, the method will only be used if
+ this file exists; e.g. for the <literal>bzip2</literal> 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 the configuration files you can set the option direct - not in list style.
<varlistentry><term><option>AllowInsecureRepositories</option></term>
<listitem><para>
- Allow the update operation to load data files from
- a repository without a trusted signature. If enabled this
- option no data files will be loaded and the update
- operation fails with a error for this source. The default
- is false for backward compatibility. This will be changed
- in the future.
+ Allow update operations to load data files from
+ repositories without sufficient security information.
+ The default value is "<literal>false</literal>".
+ Concept, implications as well as alternatives are detailed in &apt-secure;.
</para></listitem>
</varlistentry>
- <varlistentry><term><option>AllowDowngradeToInsecureRepositories</option></term>
+ <varlistentry><term><option>AllowWeakRepositories</option></term>
<listitem><para>
- Allow that a repository that was previously gpg signed to become
- unsigned durign a update operation. When there is no valid signature
- of a perviously trusted repository apt will refuse the update. This
- option can be used to override this protection. You almost certainly
- never want to enable this. The default is false.
+ Allow update operations to load data files from
+ repositories which provide security information, but these
+ are deemed no longer cryptographically strong enough.
+ The default value is "<literal>false</literal>".
+ Concept, implications as well as alternatives are detailed in &apt-secure;.
+ </para></listitem>
+ </varlistentry>
- Note that apt will still consider packages from this source
- untrusted and warn about them if you try to install
- them.
- </para></listitem>
+ <varlistentry><term><option>AllowDowngradeToInsecureRepositories</option></term>
+ <listitem><para>
+ Allow that a repository that was previously gpg signed to become
+ unsigned during an update operation. When there is no valid signature
+ for a previously trusted repository apt will refuse the update. This
+ option can be used to override this protection. You almost certainly
+ never want to enable this. The default is <literal>false</literal>.
+ Concept, implications as well as alternatives are detailed in &apt-secure;.
+ </para></listitem>
</varlistentry>
<varlistentry><term><option>Changelogs::URI</option> scope</term>
<listitem><para>These options are passed to &dpkg-buildpackage; when compiling packages;
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 such a way as to let it make aggressive use of triggers over
- multiple calls of &dpkg;. Without further options &dpkg; will use triggers once each time it runs.
- Activating these options can therefore decrease the time needed to perform the
- install or upgrade. Note that it is intended to activate these options per default in the
- future, but as it drastically changes the way APT calls &dpkg; it needs a lot more testing.
- <emphasis>These options are therefore currently experimental and should not be used in
- production environments.</emphasis> It also breaks progress reporting such that all front-ends 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><option>DPkg::NoTriggers</option></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 also add this flag to the unpack and remove calls.</para></listitem>
- </varlistentry>
- <varlistentry><term><option>PackageManager::Configure</option></term>
- <listitem><para>Valid values are "<literal>all</literal>",
- "<literal>smart</literal>" and "<literal>no</literal>".
- The default value is "<literal>all</literal>", which causes APT to
- configure all packages. The "<literal>smart</literal>" way is to
- configure only packages which need to be configured before another
- package can be unpacked (Pre-Depends), and let the rest be configured
- by &dpkg; with a call generated by the ConfigurePending option (see
- below). On the other hand, "<literal>no</literal>" will not configure
- anything, and totally relies on &dpkg; for configuration (which at the
- moment will fail if a Pre-Depends is encountered). Setting this option
- to any value other than <literal>all</literal> will implicitly also
- activate the next option by default, as otherwise the system could end
- in an unconfigured and potentially unbootable state.</para></listitem>
- </varlistentry>
- <varlistentry><term><option>DPkg::ConfigurePending</option></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 automatically
- per default if the previous option is not set to <literal>all</literal>, but deactivating it 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><option>DPkg::TriggersPending</option></term>
- <listitem><para>Useful for the <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 showstopper 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><option>OrderList::Score::Immediate</option></term>
- <listitem><para>Essential packages (and their dependencies) should be configured immediately
- after unpacking. It is a good idea to do this quite early in the upgrade process as these
- configure calls also currently require <literal>DPkg::TriggersPending</literal> which
- will run quite a few triggers (which may not be needed). Essentials get per default a high score
- but the immediate flag is relatively low (a package which has a Pre-Depends is rated higher).
- These option and the others in the same group can be used to change the scoring. The following
- example shows the settings with their default values.
- <literallayout>OrderList::Score {
- Delete 500;
- Essential 200;
- Immediate 10;
- PreDepends 50;
-};</literallayout>
- </para></listitem>
- </varlistentry>
- </variablelist>
- </refsect2>
+ <varlistentry><term><option>DPkg::ConfigurePending</option></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 by default,
+ but deactivating it could be useful if you want to run APT multiple times in a row - e.g. in an installer.
+ In this scenario you could deactivate this option in all but the last run.</para></listitem>
+ </varlistentry>
+ </variablelist>
</refsect1>
<refsect1>
<title>Periodic and Archives options</title>
<para><literal>APT::Periodic</literal> and <literal>APT::Archives</literal>
groups of options configure behavior of apt periodic updates, which is
- done by the <literal>/etc/cron.daily/apt</literal> script. See the top of
+ done by the <literal>/usr/lib/apt/apt.systemd.daily</literal> script. See the top of
this script for the brief documentation of these options.
</para>
</refsect1>
projects / apt.git / blobdiff