# Micro Service Definition

## Introduction Use microservice.yaml to describe your service

Conceptions: - instance: one process is a micro service instance, instances belong to one micro service - service: service is a static information entity in storage, it has instances

you can consider a project as an micro service, after compile, build and run, it became a micro service instance

## Configurations

name > (required, string) Micro service name

hostname > (optional, string) hostname of host, it can be IP, $INTERNAL_IP placeholder or hostname, default is hostname return by os.hostname() > When specify hostname: $INTERNAL_IP go-chassis will report ip address instead of hostname to service center, this is useful when hostname is meaningless in some scenes, such as a docker host.

APPLICATION_ID > (optional, string) Application ID, default value is “default”

version > (optional, string) version number default is 0.0.1

properties > (optional, map) micro service metadata ，usually it is defined in project, and never changed

instanceProperties > (optional, map) instance metadata, during runtime, it can be different based on environment

paths > (optional, array) micro service API paths, will be registered with servicecenter

schemas >*(optional, array)* schema id, which will be registered with servicecenter

## Example

```yaml servicecomb:

service:

name: Server hostname: 10.244.1.3 properties:

project: X1

instanceProperties:

nodeIP: 192.168.0.111

paths: - path: /rest/demoservice

property:

checksession: true

schemas: - “schema” - “schema1” - “schema2”

```