designed to support any number of active sources and a variety of source
media. The files list one source per line (one line style) or contain multiline
stanzas defining one or more sources per stanza (deb822 style), with the
- most preferred source listed first. The information available from the
+ most preferred source listed first (in case a single version is available from more than one source). The information available from the
configured sources is acquired by <command>apt-get update</command> (or
by an equivalent command from another APT front-end).
</para>
APT versions.
<itemizedlist>
- <listitem><para><literal>Architectures</literal>
- (<literal>arch</literal>) is a multivalue option defining for
+ <listitem><para><option>Architectures</option>
+ (<option>arch</option>) is a multivalue option defining for
which architectures information should be downloaded. If this
option isn't set the default is all architectures as defined by
- the <literal>APT::Architectures</literal> config option.
+ the <option>APT::Architectures</option> config option.
</para></listitem>
- <listitem><para><literal>Languages</literal>
- (<literal>lang</literal>) is a multivalue option defining for
+ <listitem><para><option>Languages</option>
+ (<option>lang</option>) is a multivalue option defining for
which languages information like translated package
descriptions should be downloaded. If this option isn't set
the default is all languages as defined by the
- <literal>Acquire::Languages</literal> config option.
+ <option>Acquire::Languages</option> config option.
</para></listitem>
- <listitem><para><literal>Targets</literal>
- (<literal>target</literal>) is a multivalue option defining
+ <listitem><para><option>Targets</option>
+ (<option>target</option>) is a multivalue option defining
which download targets apt will try to acquire from this
source. If not specified, the default set is defined by the
- <literal>APT::Acquire::Targets</literal> configuration scope.
+ <option>Acquire::IndexTargets</option> configuration scope.
+ Aditionally, specific targets can be enabled or disabled by
+ using the identifier as field name instead of using this
+ multivalue option.
</para></listitem>
+
+ <listitem><para><option>PDiffs</option> (<option>pdiffs</option>)
+ is a yes/no value which controls if APT should try to use PDiffs
+ to update old indexes instead of downloading the new indexes
+ entirely. The value of this option is ignored if the repository
+ doesn't announce the availability of PDiffs. Defaults to the
+ value of the option with the same name for a specific index file
+ defined in the <option>Acquire::IndexTargets</option> scope,
+ which itself default to the value of configuration option
+ <option>Acquire::PDiffs</option> which defaults to
+ <literal>yes</literal>.
+ </para></listitem>
+
+ <listitem><para><option>By-Hash</option> (<option>by-hash</option>)
+ can have the value "yes", "no" or "force" and controls if APT
+ should try to acquire indexes via an URI constructed from a
+ hashsum of the expected file instead of using the well-known
+ stable filename of the index. Using this can avoid hashsum
+ mismatches, but requires a supporting mirror. The value
+ "yes"/"no" activates/disables the use of this feature if this
+ source indicates support for it, while "force" will enable the
+ feature regardless of what the source indicates.
+ Defaults to the value of the option of the same name for a
+ specific index file defined in the
+ <option>Acquire::IndexTargets</option> scope, which itself
+ defaults to the value of configuration option
+ <option>Acquire::By-Hash</option> which defaults to
+ <literal>yes</literal>.
+ </para></listitem>
+
</itemizedlist>
Further more, there are options which if set effect
anomalies.
<itemizedlist>
- <listitem><para><literal>Trusted</literal> (<literal>trusted</literal>)
- is a tri-state value which defaults to APT deciding if a source
- is considered trusted or if warnings should be raised before e.g.
- packages are installed from this source. This option can be used
- to override this decision either with the value <literal>yes</literal>,
- which lets APT consider this source always as a trusted source
- even if it has no or fails authentication checks by disabling parts
- of &apt-secure; and should therefore only be used in a local and trusted
- context (if at all) as otherwise security is breached. The opposite
- can be achieved with the value no, which causes the source to be handled
- as untrusted even if the authentication checks passed successfully.
- The default value can't be set explicitly.
+ <listitem><para><option>Signed-By</option> (<option>signed-by</option>)
+ is either an absolute path to a keyring file (has to be
+ accessible and readable for the <literal>_apt</literal> user,
+ so ensure everyone has read-permissions on the file) or a
+ fingerprint of a key in either the
+ <filename>trusted.gpg</filename> keyring or in one of the
+ keyrings in the <filename>trusted.gpg.d/</filename> directory
+ (see <command>apt-key fingerprint</command>). If the option is
+ set only the key(s) in this keyring or only the key with this
+ fingerprint is used for the &apt-secure; verification of this
+ repository. Otherwise all keys in the trusted keyrings are
+ considered valid signers for this repository.
</para></listitem>
+
+ <listitem><para><option>Check-Valid-Until</option> (<option>check-valid-until</option>)
+ is a yes/no value which controls if APT should try to detect
+ replay attacks. A repository creator can declare until then the
+ data provided in the repository should be considered valid and
+ if this time is reached, but no new data is provided the data
+ is considered expired and an error is raised. Beside
+ increasing security as a malicious attacker can't sent old data
+ forever denying a user to be able to upgrade to a new version,
+ this also helps users identify mirrors which are no longer
+ updated. Some repositories like historic archives aren't
+ updated anymore by design through, so this check can be
+ disabled by setting this option to <literal>no</literal>.
+ Defaults to the value of configuration option
+ <option>Acquire::Check-Valid-Until</option> which itself
+ defaults to <literal>yes</literal>.
+ </para></listitem>
+
+ <listitem><para><option>Valid-Until-Min</option>
+ (<option>valid-until-min</option>) and
+ <option>Valid-Until-Max</option>
+ (<option>valid-until-max</option>) can be used to raise or
+ lower the time period in seconds in which the data from this
+ repository is considered valid. -Max can be especially useful
+ if the repository provides no Valid-Until field on its Release
+ file to set your own value, while -Min can be used to increase
+ the valid time on seldom updated (local) mirrors of a more
+ frequently updated but less accessible archive (which is in the
+ sources.list as well) instead of disabling the check entirely.
+ Default to the value of the configuration options
+ <option>Acquire::Min-ValidTime</option> and
+ <option>Acquire::Max-ValidTime</option> which are both unset by
+ default.
+ </para></listitem>
+
</itemizedlist>
</para>
projects / apt.git / blobdiff