pip_services4_container

Description:

pip services4 container

IoC container for Dart #
This module is a part of the Pip.Services polyglot microservices toolkit. It provides an inversion-of-control (IoC) container to facilitate the development of services and applications composed of loosely coupled components.
The module containes a basic in-memory container that can be embedded inside a service or application, or can be run by itself.
The second container type can run as a system level process and can be configured via command line arguments.
Also it can be used to create docker containers.
The containers can read configuration from JSON or YAML files use it as a recipe for instantiating and configuring components.
Component factories are used to create components based on their locators (descriptor) defined in the container configuration.
The factories shall be registered in containers or dynamically in the container configuration file.
The module contains the following packages:

Containers - Basic in-memory and process containers
Build - Default container factory
Config - Container configuration components
Refer - Inter-container reference management (implementation of the Referenceable pattern inside an IoC container)

Quick links:

Configuration
API Reference
Change Log
Get Help
Contribute

Use #
Add this to your package's pubspec.yaml file:
dependencies:
pip_services4_container: version
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Now you can install package from the command line:
pub get
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Create a factory to create components based on their locators (descriptors).
import 'package:pip_services4_components/src/build/Factory.dart';
import 'package:pip_services4_components/src/refer/Descriptor.dart';

class MyFactory extends Factory {
static final MyComponentDescriptor =
Descriptor('myservice', 'mycomponent', 'default', '*', '1.0');

MyFactory() : super() {
registerAsType(MyFactory.MyComponentDescriptor, MyComponent);
}
}

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Then create a process container and register the factory there. You can also register factories defined in other
modules if you plan to include external components into your container.
import 'package:pip_services4_container/src/ProcessContainer.dart';
import 'package:pip_services4_rpc/src/build/DefaultRpcFactory.dart';

class MyProcess extends ProcessContainer {
MyProcess() : super('myservice', 'My service running as a process') {
factories.add(DefaultRpcFactory());
factories.add(MyFactory());
}
}
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Define YAML configuration file with components and their descriptors.
The configuration file is pre-processed using Handlebars templating engine
that allows to inject configuration parameters or dynamically include/exclude components using conditional blocks.
The values for the templating engine are defined via process command line arguments or via environment variables.
Support for environment variables works well in docker or other containers like AWS Lambda functions.
---
# Context information
- descriptor: "pip-services:context-info:default:default:1.0"
name: myservice
description: My service running in a process container

# Console logger
- descriptor: "pip-services:logger:console:default:1.0"
level: {{LOG_LEVEL}}{{^LOG_LEVEL}}info{{/LOG_LEVEL}}

# Performance counters that posts values to log
- descriptor: "pip-services:counters:log:default:1.0"

# My component
- descriptor: "myservice:mycomponent:default:default:1.0"
param1: XYZ
param2: 987

{{#if HTTP_ENABLED}}
# HTTP endpoint version 1.0
- descriptor: "pip-services:endpoint:http:default:1.0"
connection:
protocol: "http"
host: "0.0.0.0"
port: {{HTTP_PORT}}{{^HTTP_PORT}}8080{{/HTTP_PORT}}

# Default Status
- descriptor: "pip-services:status-service:http:default:1.0"

# Default Heartbeat
- descriptor: "pip-services:heartbeat-service:http:default:1.0"
{{/if}}
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To instantiate and run the container we need a simple process launcher.
void main(List<String> args) {
try {
var proc = MyProcess();
proc.configPath = './config/config.yml';
proc.run(args);
} catch (ex) {
print(ex);
}
}
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And, finally, you can run your service launcher as
dart run ./service.dart
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Develop #
For development you shall install the following prerequisites:

Dart SDK 3
Visual Studio Code or another IDE of your choice
Docker

Install dependencies:
pub get
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Run automated tests:
pub run test
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Generate API documentation:
./docgen.ps1
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Before committing changes run dockerized build and test as:
./build.ps1
./test.ps1
./clear.ps1
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Contacts #
The Dart version of Pip.Services is created and maintained by:

Sergey Seroukhov
Levichev Dmitry

The documentation is written by:

Mark Makarychev
Levichev Dmitry