# Counters Microservice Client SDK for Node.js / ES2017 V2

This is a Node.js client SDK for counters microservice.
It provides an easy to use abstraction over communication protocols:

- HTTP/REST client
- Direct client for monolithic deployments
- Null client to be used in testing

This client SDK also contains Direct and REST loggers that allow to directly log into the microservice.

<a name="links"></a> Quick Links:

- [Install](#install)
- [Use](#use)
- [Develop](#develop)
- [Configure](#configure)
- [Run](#run)
- [Source Documentation](docs/index.html)

## <a name="install"></a> Install

Add dependency to the client SDK into **package.json** file of your project

```javascript
{
    ...
    "dependencies": {
        ....
        "client-perfmon2-node": "^1.0.*",
        ...
    }
}
```

Then install the dependency using **npm** tool

```bash
# Install new dependencies
npm install

# Update already installed dependencies
npm update
```

## <a name="use"></a> Use

Inside your code get the reference to the client library

```javascript
var sdk = new require("client-perfmon2-node");
```

Define client configuration parameters that match configuration of the microservice external API

```javascript
// Client configuration
var config = {
  connection: {
    protocol: "http",
    host: "localhost",
    port: 8080,
  },
};
```

Instantiate the client and open connection to the microservice

```javascript
// Create the client instance
var client = sdk.CountersHttpClientV1(config);

// Connect to the microservice
try {
    await client.open(null);
    // Work with the microservice
    ...
} catch(err) {
    console.error('Connection to the microservice failed');
    console.error(err);
}
```

Now the client is ready to perform operations

```javascript
// Write counter
let counter = await client.writeCounter(null, {
  time: new Date(),
  level: 4,
  counter: "Server restarted",
});
```

```javascript
var now = new Date();

// Read counters
let page = await client.readCounters(
  null,
  {
    search: "server",
    from_time: new Date(now.getTime() - 24 * 3600 * 1000),
    to_time: now,
  },
  {
    total: true,
    skip: 0,
    take: 100,
  }
);
```

## <a name="develop"></a> Develop

This client library is written in TypeScript language which is transcompiled into JavaScript.
So, if you make changes to the source code you need to compile it before running or committing to github.
The process will output compiled javascript files into /bin folder.

```bash
tsc
```

When you do continuous edit-build-test cycle, you can run typescript compiler with --watch option
to detect and compile changes you make automatically:

```bash
tsc --watch
```

Command to run unit tests:

```bash
npm test
```

You can also execute benchmarks as:

```bash
npm run benchmark
```

## <a name="configure"></a> Configure

Configuration for this microservice is stored in "./config/config.yml" file.
This configuration file contains common structure for configuring all microservices:

```yaml
---
# Container descriptor
- descriptor:
    group: "example"
    persistence: "memory"
    service: "*"
    version: "1.0"
  # ...
  # Other container configuration parameters
  # ...
```

## <a name="run"></a> Run

The client library can be run as a dependency to other programs or run as a process:

```bash
node ./bin/main.js
```

## Acknowledgements

This client library was created and currently maintained by _Sergey Seroukhov_ and _Danylo Kuznetsov_ (jkuznetsov@entinco.com).