docs/admin/searx.favicons.rst
.. _favicons:
.. sidebar:: warning
Don't activate the favicons before reading the documentation.
.. contents:: :depth: 2 :local: :backlinks: entry
Activating the favicons in SearXNG is very easy, but this generates a significantly higher load in the client/server communication and increases resources needed on the server.
To mitigate these disadvantages, various methods have been implemented, including a cache. The cache must be parameterized according to your own requirements and maintained regularly.
To activate favicons in SearXNG's result list, set a default
favicon_resolver in the :ref:search <settings search> settings:
.. code:: yaml
search: favicon_resolver: "duckduckgo"
By default and without any extensions, SearXNG serves these resolvers:
duckduckgoallesedvgoogleyandexWith the above setting favicons are displayed, the user has the option to
deactivate this feature in his settings. If the user is to have the option of
selecting from several resolvers, a further setting is required / but this
setting will be discussed :ref:later <register resolvers> in this article,
first we have to setup the favicons cache.
The infrastructure for providing the favicons essentially consists of three parts:
Favicons-Proxy <.favicons.proxy> (aka proxy)Favicons-Resolvers <.favicons.resolvers> (aka resolver)Favicons-Cache <.favicons.cache> (aka cache)To protect the privacy of users, the favicons are provided via a proxy. This proxy is automatically activated with the above activation of a resolver. Additional requests are required to provide the favicons: firstly, the proxy must process the incoming requests and secondly, the resolver must make outgoing requests to obtain the favicons from external sources.
A cache has been developed to massively reduce both, incoming and outgoing requests. This cache is also activated automatically with the above activation of a resolver. In its defaults, however, the cache is minimal and not well suitable for a production environment!
.. _favicon cache setup:
To parameterize the cache and more settings of the favicons infrastructure, a
TOML_ configuration is created in the file /etc/searxng/favicons.toml.
.. code:: toml
[favicons]
cfg_schema = 1 # config's schema version no.
[favicons.cache]
db_url = "/var/cache/searxng/faviconcache.db" # default: "/tmp/faviconcache.db" LIMIT_TOTAL_BYTES = 2147483648 # 2 GB / default: 50 MB
:py:obj:cfg_schema <.FaviconConfig.cfg_schema>:
Is required to trigger any processes required for future upgrades / don't
change it.
:py:obj:cache.db_url <.FaviconCacheConfig.db_url>:
The path to the (SQLite_) database file. The default path is in the /tmp_
folder, which is deleted on every reboot and is therefore unsuitable for a
production environment. The FHS_ provides the folder /var/cache_ for the
cache of applications, so a suitable storage location of SearXNG's caches is
folder /var/cache/searxng.
In a standard installation (compare :ref:create searxng user), the folder
must be created and the user under which the SearXNG process is running must
be given write permission to this folder.
.. code:: bash
$ sudo mkdir /var/cache/searxng
$ sudo chown root:searxng /var/cache/searxng/
$ sudo chmod g+w /var/cache/searxng/
In container systems, a volume should be mounted for this folder. Check whether the process in the container has read/write access to the mounted folder.
:py:obj:cache.LIMIT_TOTAL_BYTES <.FaviconCacheConfig.LIMIT_TOTAL_BYTES>:
Maximum of bytes stored in the cache of all blobs. The limit is only reached
at each maintenance interval after which the oldest BLOBs are deleted; the
limit is exceeded during the maintenance period.
.. attention::
If the maintenance period is too long or maintenance is switched
off completely, the cache grows uncontrollably.
SearXNG hosters can change other parameters of the cache as required:
cache.HOLD_TIME <.FaviconCacheConfig.HOLD_TIME>cache.BLOB_MAX_BYTES <.FaviconCacheConfig.BLOB_MAX_BYTES>Regular maintenance of the cache is required! By default, regular maintenance is triggered automatically as part of the client requests:
cache.MAINTENANCE_MODE <.FaviconCacheConfig.MAINTENANCE_MODE> (default auto)cache.MAINTENANCE_PERIOD <.FaviconCacheConfig.MAINTENANCE_PERIOD> (default 6000 / 1h)As an alternative to maintenance as part of the client request process, it is
also possible to carry out maintenance using an external process. For example,
by creating a :man:crontab entry for maintenance:
.. code:: bash
$ python -m searx.favicons cache maintenance
The following command can be used to display the state of the cache:
.. code:: bash
$ python -m searx.favicons cache state
.. _favicon proxy setup:
Most of the options of the :py:obj:Favicons-Proxy <.favicons.proxy> are
already set sensibly with settings from the :ref:settings.yml <searxng settings.yml> and should not normally be adjusted.
.. code:: toml
[favicons.proxy]
max_age = 5184000 # 60 days / default: 7 days (604800 sec)
:py:obj:max_age <.FaviconProxyConfig.max_age>:
The HTTP Cache-Control max-age_ response directive indicates that the
response remains fresh until N seconds after the response is generated. This
setting therefore determines how long a favicon remains in the client's cache.
As a rule, in the favicons infrastructure of SearXNG's this setting only
affects favicons whose byte size exceeds :ref:BLOB_MAX_BYTES <favicon cache setup> (the other favicons that are already in the cache are embedded as
data URL_ in the :py:obj:generated HTML <.favicons.proxy.favicon_url>,
which can greatly reduce the number of additional requests).
.. _register resolvers:
A :py:obj:resolver <.favicon.resolvers> is a function that obtains the favicon
from an external source. The resolver functions available to the user are
registered with their fully qualified name (FQN_) in a resolver_map.
If no resolver_map is defined in the favicon.toml, the favicon
infrastructure of SearXNG generates this resolver_map automatically
depending on the settings.yml. SearXNG would automatically generate the
following TOML configuration from the following YAML configuration:
.. code:: yaml
search: favicon_resolver: "duckduckgo"
.. code:: toml
[favicons.proxy.resolver_map]
"duckduckgo" = "searx.favicons.resolvers.duckduckgo"
If this automatism is not desired, then (and only then) a separate
resolver_map must be created. For example, to give the user two resolvers to
choose from, the following configuration could be used:
.. code:: toml
[favicons.proxy.resolver_map]
"duckduckgo" = "searx.favicons.resolvers.duckduckgo" "allesedv" = "searx.favicons.resolvers.allesedv"
.. note::
With each resolver, the resource requirement increases significantly.
The number of resolvers increases:
In the following we list the resolvers available in the core of SearXNG, but via the FQN_ it is also possible to implement your own resolvers and integrate them into the proxy:
searx.favicons.resolvers.duckduckgosearx.favicons.resolvers.allesedvsearx.favicons.resolvers.googlesearx.favicons.resolvers.yandex.. _SQLite:
https://www.sqlite.org/
.. _FHS:
https://refspecs.linuxfoundation.org/FHS_3.0/fhs/index.html
.. _/var/cache:
https://refspecs.linuxfoundation.org/FHS_3.0/fhs/ch05s05.html
.. _/tmp:
https://refspecs.linuxfoundation.org/FHS_3.0/fhs/ch03s18.html
.. _TOML:
https://toml.io/en/
.. _HTTP Cache-Control max-age:
https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cache-Control#response_directives
.. _data URL:
https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/Data_URLs
.. _FQN: https://en.wikipedia.org/wiki/Fully_qualified_name