Rework Dockerfile (#4699)

This is one of various PR to refactor the entire SearXNG Docker workflow.

Switches to Python glibc based images, all dependencies are installed via pip and not from system repositories, and several minor changes.

This PR will increase the image size from 194.9 MB to 345.47 MB (amd64), this is due to ARMv7 images (needs dependencies for wheels compilation and runtime (?)) and uWSGI webserver. Later PR will reduce the final image size.

dockerfiles/docker-entrypoint.sh

@@ -43,15 +43,7 @@ do
     esac
 done
 
-get_searxng_version(){
-    su searxng -c \
-       'python3 -c "import six; import searx.version; six.print_(searx.version.VERSION_STRING)"' \
-       2>/dev/null
-}
-
-SEARXNG_VERSION="$(get_searxng_version)"
-export SEARXNG_VERSION
-echo "SearXNG version ${SEARXNG_VERSION}"
+echo "SearXNG version $SEARXNG_VERSION"
 
 # helpers to update the configuration files
 patch_uwsgi_settings() {
@@ -76,7 +68,7 @@ patch_searxng_settings() {
         -e "s|base_url: false|base_url: ${BASE_URL}|g" \
         -e "s/instance_name: \"SearXNG\"/instance_name: \"${INSTANCE_NAME}\"/g" \
         -e "s/autocomplete: \"\"/autocomplete: \"${AUTOCOMPLETE}\"/g" \
-        -e "s/ultrasecretkey/$(openssl rand -hex 32)/g" \
+        -e "s/ultrasecretkey/$(head -c 24 /dev/urandom | base64 | tr -dc 'a-zA-Z0-9')/g" \
         "${CONF}"
 
     # Morty configuration
@@ -172,4 +164,4 @@ printf 'Listen on %s\n' "${BIND_ADDRESS}"
 
 # Start uwsgi
 # TODO: "--http-socket" will be removed in the future (see uwsgi.ini.new config file): https://github.com/searxng/searxng/pull/4578
-exec uwsgi --http-socket "${BIND_ADDRESS}" "${UWSGI_SETTINGS_PATH}"
+exec /usr/local/searxng/venv/bin/uwsgi --http-socket "${BIND_ADDRESS}" "${UWSGI_SETTINGS_PATH}"