uwsgi

Origin uWSGI

How uWSGI is implemented by distributors is different. uWSGI itself recommend two methods

systemd.unit template files as described here One service per app in systemd.

There is one systemd unit template and one uwsgi ini file per uWSGI-app placed at dedicated locations. Take archlinux and a searxng.ini as example:

unit template    -->  /usr/lib/systemd/system/uwsgi@.service
uwsgi ini files  -->  /etc/uwsgi/searxng.ini

The SearXNG app can be maintained as know from common systemd units:

systemctl enable  uwsgi@searx
systemctl start   uwsgi@searx
systemctl restart uwsgi@searx
systemctl stop    uwsgi@searx

The uWSGI Emperor mode which fits for maintaining a large range of uwsgi apps.

The Emperor mode is a special uWSGI instance that will monitor specific events. The Emperor mode (service) is started by a (common, not template) systemd unit. The Emperor service will scan specific directories for uwsgi ini files (also know as vassals). If a vassal is added, removed or the timestamp is modified, a corresponding action takes place: a new uWSGI instance is started, reload or stopped. Take Fedora and a searxng.ini as example:

to start a new SearXNG instance create --> /etc/uwsgi.d/searxng.ini
to reload the instance edit timestamp  --> touch /etc/uwsgi.d/searxng.ini
to stop instance remove ini            --> rm /etc/uwsgi.d/searxng.ini

Distributors

The uWSGI Emperor mode and systemd unit template is what the distributors mostly offer their users, even if they differ in the way they implement both modes and their defaults. Another point they might differ is the packaging of plugins (if so, compare Install packages) and what the default python interpreter is (python2 vs. python3).

Fedora starts a Emperor by default, while archlinux does not start any uwsgi service by default. Worth to know; debian (ubuntu) follow a complete different approach. debian: your are familiar with the apache infrastructure? .. they do similar for the uWSGI infrastructure (with less comfort), the folders are:

/etc/uwsgi/apps-available/
/etc/uwsgi/apps-enabled/

The uwsgi ini file is enabled by a symbolic link:

ln -s /etc/uwsgi/apps-available/searxng.ini /etc/uwsgi/apps-enabled/

From debian’s documentation (/usr/share/doc/uwsgi/README.Debian.gz): You could control specific instance(s) by issuing:

service uwsgi <command> <confname> <confname> ...

sudo -H service uwsgi start searx
sudo -H service uwsgi stop  searx

My experience is, that this command is a bit buggy.

Alltogether

Create the configuration ini-file according to your distribution (see below) and restart the uwsgi application.

# init.d --> /usr/share/doc/uwsgi/README.Debian.gz
# For uWSGI debian uses the LSB init process, this might be changed
# one day, see https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=833067

create     /etc/uwsgi/apps-available/searxng.ini
enable:    sudo -H ln -s /etc/uwsgi/apps-available/searxng.ini /etc/uwsgi/apps-enabled/
start:     sudo -H service uwsgi start   searxng
restart:   sudo -H service uwsgi restart searxng
stop:      sudo -H service uwsgi stop    searxng
disable:   sudo -H rm /etc/uwsgi/apps-enabled/searxng.ini

# -*- mode: conf; coding: utf-8  -*-
[uwsgi]

# uWSGI core
# ----------
#
# https://uwsgi-docs.readthedocs.io/en/latest/Options.html#uwsgi-core

# Who will run the code
uid = searx
gid = searx

# set (python) default encoding UTF-8
env = LANG=C.UTF-8
env = LANGUAGE=C.UTF-8
env = LC_ALL=C.UTF-8

# chdir to specified directory before apps loading
chdir = /usr/local/searx/searx-src/searx

# SearXNG configuration (settings.yml)
env = SEARXNG_SETTINGS_PATH=/etc/searxng/settings.yml

# disable logging for privacy
disable-logging = true

# The right granted on the created socket
chmod-socket = 666

# Plugin to use and interpretor config
single-interpreter = true

# enable master process
master = true

# load apps in each worker instead of the master
lazy-apps = true

# load uWSGI plugins
plugin = python3,http

# By default the Python plugin does not initialize the GIL.  This means your
# app-generated threads will not run.  If you need threads, remember to enable
# them with enable-threads.  Running uWSGI in multithreading mode (with the
# threads options) will automatically enable threading support. This *strange*
# default behaviour is for performance reasons.
enable-threads = true


# plugin: python
# --------------
#
# https://uwsgi-docs.readthedocs.io/en/latest/Options.html#plugin-python

# load a WSGI module
module = searx.webapp

# set PYTHONHOME/virtualenv
virtualenv = /usr/local/searx/searx-pyenv

# add directory (or glob) to pythonpath
pythonpath = /usr/local/searx/searx-src


# speak to upstream
# -----------------
#
# Activate the 'http' configuration for filtron or activate the 'socket'
# configuration if you setup your HTTP server to use uWSGI protocol via sockets.

# using IP:
#
# https://uwsgi-docs.readthedocs.io/en/latest/Options.html#plugin-http
# Native HTTP support: https://uwsgi-docs.readthedocs.io/en/latest/HTTP.html

http = 127.0.0.1:8888

# using unix-sockets:
#
# On some distributions you need to create the app folder for the sockets::
#
#   mkdir -p /run/uwsgi/app/searxng
#   chown -R searx:searx /run/uwsgi/app/searxng/socket
#
# socket = /run/uwsgi/app/searxng/socket

# uwsgi serves the static files
# expires set to one year since there are hashes
static-map = /static=/usr/local/searx/searx-src/searx/static
static-expires = /* 31557600
static-gzip-all = True
offload-threads = %k

# Cache
cache2 = name=searxngcache,items=2000,blocks=2000,blocksize=4096,bitmap=1