Hot Reload For Server

[tauseefsshah]

Just got my hands on the framework and while trying out stuff I felt the need for a hot reloading server because it's a very handy and a convenient feature to have. I feel having to restart the server after every code change is inefficient.

I might have missed it but if there's a way to achieve it, I'll appreciate you sharing.

[clue]

@tauseefsshah Thanks for bringing this up, I agree that hot reloading the source code would be a nice feature!

At the moment, the easiest work around is to use PHP's development web server for development purposes and the built-in web server for production use:

# development (reloads source for every request)
$ php -S localhost:8080 public/index.php

# deployment (keeps everything in memory)
$ php public/index.php

X supports running anywhere and we can take advantage of this for development purposes as both modes can be used mostly interchangeably.

Longer term, we're definitely interested in bringing in hot reloading also for the built-in web server. Unfortunately, this is non-trivial as checking the filesystem is inherently blocking and as such rather costly. Periodically spawning a child process (how often?) only for this purpose seems quite excessive; taking advantage of inotify might be option, but either requires an extension or FFI, so I'm not sure how feasible this is. We've also discussed an option to use a filesystem monitor in sytemd to restart the service unit if that's your cup of tea. Many options…

Would love to hear more input on this! 👍

[tauseefsshah]

@staabm PHP's development web server is awesome but personally for local development I prefer setting up vhosts with .localhost TLD so that I never have to start or stop the server.

[staabm]

ok, so in other words you would prefer a maybe slower feedback loop with hot reloading on every request, over a one time start/stop development server process? I don't judge you for that, just want to make sure I get your point.

[tauseefsshah]

hot reloading on every request

Yes but it hot reloads on every file change not on every request.

[john-everden]

I wonder if making a development base docker image and publishing it with fswatch and some configurable options would be sufficient?

[SimonFrings]

@john-everden Sounds interesting, more options more better!
We're currently involved in some other features for Framework X but we're always happy about PRs 👍

[mahmutbayri]

I use https://github.com/seregazhuk/php-watcher and It works fine.

[clue]

@mahmutbayri Also a great suggestion and great work by @seregazhuk! ❤️

I wonder if it makes sense to implement a similar logic as part of X?

[mahmutbayri]

@mahmutbayri Also a great suggestion and great work by @seregazhuk! ❤️

I wonder if it makes sense to implement a similar logic as part of X?

I use like that

X_LISTEN=0.0.0.0:8081 ./vendor/bin/php-watcher --watch src --watch resources public/index.php --ext=php,twig

it helped me a lot.

[john-everden]

Doesn't appear to support PHP 8.1 yet :(

[mahmutbayri]

Please install it like this.

composer global require seregazhuk/php-watcher:dev-master
or
composer require seregazhuk/php-watcher:dev-master

[clue]

Small update: I've started working on this and have a working prototype ready:

See https://twitter.com/another_clue/status/1545359689961144320

Current focus is to detect changes for included files which already works just fine. Once changes are detected, the process is restarted. The server socket will temporarily be paused without closing and will be reused in the new process, so there should be zero downtime.

However, we should also properly handle any active connections that may exist when a change is detected. The idea is to soft-close any connections and have a fallback to kill any remaining connections after a second. This is doable for all incoming connections, but similar logic should also trigger for any outgoing connections (think an idle connection to your database). PHP lacks low-level system access, but we may utilize FFI (optional, PHP 7.4+) to close any remaining connections.

I'll try to keep this updated as we make progress 👍

[netcarver]

What about entr?

From the public/ dir...

ls | entr -r php index.php

Should restart X whenever anything in public/ changes.