--- title: Socket Activation with Popular Daemons category: Manuals and Documentation for Users and Administrators layout: default SPDX-License-Identifier: LGPL-2.1-or-later --- ## nginx nginx includes an undocumented, internal socket-passing mechanism based on the `NGINX` environmental variable. It uses this to perform reloads without having to close and reopen its sockets, but it's also useful for socket activation. **/etc/nginx/my-nginx.conf** ``` http { server { listen [::]:80 ipv6only=on; listen 80; } } ``` **/etc/systemd/system/my-nginx.service** ``` [Service] User=nginx Group=nginx Environment=NGINX=3:4; ExecStart=/usr/sbin/nginx -c/etc/nginx/my-nginx.conf PrivateNetwork=true ``` **/etc/systemd/system/my-nginx.socket** ``` [Socket] ListenStream=80 ListenStream=0.0.0.0:80 BindIPv6Only=ipv6-only After=network.target Requires=network.target [Install] WantedBy=sockets.target ``` ## PHP-FPM Like nginx, PHP-FPM includes a socket-passing mechanism an environmental variable. In PHP-FPM's case, it's `FPM_SOCKETS`. This configuration is possible with any web server that supports FastCGI (like Apache, Lighttpd, or nginx). The web server does not need to know anything special about the socket; use a normal PHP-FPM configuration. Paths are based on a Fedora 19 system. ### First, the configuration files **/etc/php-fpm.d/my-php-fpm-pool.conf** ``` [global] pid = /run/my-php-fpm-pool.pid ; Not really used by anything with daemonize = no, but needs to be writable. error_log = syslog ; Will aggregate to the service's systemd journal. daemonize = no ; systemd handles the forking. [www] listen = /var/run/my-php-fpm-pool.socket ; Must match systemd socket unit. user = nginx ; Ignored but required. group = nginx ; Ignored but required. pm = static pm.max_children = 10 slowlog = syslog ``` **/etc/systemd/system/my-php-fpm-pool.service** ``` [Service] User=nginx Group=nginx Environment="FPM_SOCKETS=/var/run/my-php-fpm-pool.socket=3" ExecStart=/usr/sbin/php-fpm --fpm-config=/etc/php-fpm.d/my-php-fpm-pool.conf KillMode=process ``` **/etc/systemd/system/my-php-fpm-pool.socket** ``` [Socket] ListenStream=/var/run/my-php-fpm-pool.socket [Install] WantedBy=sockets.target ``` ### Second, the setup commands ```sh sudo systemctl --system daemon-reload sudo systemctl start my-php-fpm-pool.socket sudo systemctl enable my-php-fpm-pool.socket ``` After accessing the web server, the service should be running. ```sh sudo systemctl status my-php-fpm-pool.service ``` It's possible to shut down the service and re-activate it using the web browser, too. It's necessary to stop and start the socket to reset some shutdown PHP-FPM does that otherwise breaks reactivation. ```sh sudo systemctl stop my-php-fpm-pool.socket my-php-fpm-pool.service sudo systemctl start my-php-fpm-pool.socket ```