51 lines
1.9 KiB
Markdown
51 lines
1.9 KiB
Markdown
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# production
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Helpers for concurrency, message-passing, rotating loggers, and other production functionality in Angel.
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This will become the de-facto way to run Angel applications in deployed environments, as it
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takes care of inter-isolate communication, respawning dead processes, and other housekeeping for you automatically.
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Most users will want to use the `Runner` class.
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## `Runner`
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`Runner` is a utility, powered by `package:args`, that is intended to be the entry point of your application.
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Instantiate it as follows, and your file will become a command-line executable that spawns multiple instances of your
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application:
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```dart
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import 'dart:async';
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import 'dart:isolate';
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import 'package:angel_framework/angel_framework.dart';
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import 'package:angel_production/angel_production.dart';
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main(List<String> args) => new Runner('example', configureServer).run(args);
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Future configureServer(Angel app) async {
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app.get('/', (req, res) => 'Hello, production world!');
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app.get('/crash', (req, res) {
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// We'll crash this instance deliberately, but the Runner will auto-respawn for us.
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new Timer(const Duration(seconds: 3), Isolate.current.kill);
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return 'Crashing in 3s...';
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});
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}
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```
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`Runner` will automatically re-spawn crashed instances, unless `--no-respawn` is passed. This can prevent
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your server from entirely going down at the first error, and adds a layer of fault tolerance to your
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infrastructure.
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When combined with `systemd`, deploying Angel applications on Linux can be very simple.
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## Message Passing
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The `Runner` class uses [`package:pub_sub`](https://github.com/thosakwe/pub_sub) to coordinate
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message passing between isolates.
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When one isolate sends a message, all other isolates will
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receive the same message, except for the isolate that sent it.
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It is injected into your application's `Container` as
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`pub_sub.Client`, so you can use it as follows:
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```dart
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```
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