[mod] Revision of the favicon solution

All favicons implementations have been documented and moved to the Python
package:

    searx.favicons

There is a configuration (based on Pydantic) for the favicons and all its
components:

    searx.favicons.config

A solution for caching favicons has been implemented:

    searx.favicon.cache

If the favicon is already in the cache, the returned URL is a data URL [1]
(something like `data:image/png;base64,...`).  By generating a data url from
the FaviconCache, additional HTTP roundtripps via the favicon_proxy are saved:

    favicons.proxy.favicon_url

The favicon proxy service now sets a HTTP header "Cache-Control: max-age=...":

    favicons.proxy.favicon_proxy

The resolvers now also provide the mime type (data, mime):

    searx.favicon.resolvers

[1] https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/Data_URLs

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

1 files changed, 37 insertions, 0 deletions

diff --git a/searx/favicons/__init__.py b/searx/favicons/__init__.py
new file mode 100644
index 000000000..2a9893932
--- /dev/null
+++ b/searx/favicons/__init__.py
@@ -0,0 +1,37 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
+"""Implementations for providing the favicons in SearXNG"""
+
+from __future__ import annotations
+
+__all__ = ["init", "favicon_url", "favicon_proxy"]
+
+import pathlib
+from searx import logger
+from searx import get_setting
+from .proxy import favicon_url, favicon_proxy
+
+logger = logger.getChild('favicons')
+
+
+def is_active():
+    return bool(get_setting("search.favicon_resolver", False))
+
+
+def init():
+
+    # pylint: disable=import-outside-toplevel
+
+    from . import config, cache, proxy
+
+    cfg_file = pathlib.Path("/etc/searxng/favicons.toml")
+    if not cfg_file.exists():
+        if is_active():
+            logger.error(f"missing favicon config: {cfg_file}")
+        cfg_file = config.DEFAULT_CFG_TOML
+
+    logger.debug(f"load favicon config: {cfg_file}")
+    cfg = config.FaviconConfig.from_toml_file(cfg_file, use_cache=True)
+    cache.init(cfg.cache)
+    proxy.init(cfg.proxy)
+
+    del cache, config, proxy, cfg