Systemd socket-based activation for http server?

[cryobry]

Would it be possible to add a systemd .socket activated service file to the default installation (when using the httpd server)? This would allow my server to use a lot less resources when the stream is not being accessed via a web interface.

[tosiara]

I'm not familiar with "systemd .socket activated service file". Can you provide more details or maybe an example of other programs using it?

[cryobry]

https://www.freedesktop.org/software/systemd/man/systemd.socket.html

# /usr/lib/systemd/system/cockpit.socket
[Unit]
Description=Cockpit Web Service Socket
Documentation=man:cockpit-ws(8)
Wants=cockpit-motd.service

[Socket]
ListenStream=9090
ExecStartPost=-/usr/share/cockpit/motd/update-motd '' localhost
ExecStartPost=-/bin/ln -snf active.motd /run/cockpit/motd
ExecStopPost=-/bin/ln -snf /usr/share/cockpit/motd/inactive.motd /run/cockpit/motd

[Install]
WantedBy=sockets.target`

The socket watches for access to the ListenStream port, after which it executes the Exec lines. This could be used to start/stop the motion service on-demand.

[tim-seoss]

This implies (I believe) that motion would not usually run - it would be started on demand by systemd when a client (e.g. a web browser) connects, and would exit after the streaming connection is closed. It wouldn't be able to do it's usual motion detection tasks etc.

If that's the case, then I think it might be a better idea to just implement this with a simple gstreamer pipeline or similar, rather than add this to motion?

If I've got this wrong, and there's a use-case for this which would utilise motion's major features, then could you outline what sort of usage you were thinking of?

[cryobry]

On point one you are correct. This is part of a lab server setup with a webcam that monitors a robotic arm. 99% of the time the server is doing heavy calculations and needs as many resources available as possible, but occasionally we need to view the robot's actions remotely in case a problem arises. On point two I am unfamiliar with gstreamer pipelines. I know this can work via systemd sockets, although there may certainly be a better way as you have indicated.

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On Fri, Feb 8, 2019 at 3:29 PM Tim Small ***@***.***> wrote: This implies (I believe) that motion would not usually run - it would be started on demand by systemd when a client (e.g. a web browser) connects, and would exit after the streaming connection is closed. It wouldn't be able to do any motion detection etc. If that's the case, then I think it might be a better idea to just implement this with a simple gstreamer pipeline or similar, rather than add this to motion? — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#882 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/Akf1CD33baI8YbFgU5cvljAqYvjaC1s4ks5vLd4NgaJpZM4Z4Y63> .