README.md

ConfigRPC

A Distributed Configuration Service Based on gRPC.

Each comfiguration is composed of a key/value pair, where the key can be any string and value is a JSON document so that nested structured configurations can be stored.

As an use case example, we at e2log.com, use a similar service to store feature toggles and parameters for each module of our B2B SaaS platform. All feature toggles and parameters for all modules are stored in a single JSON document with the customer identifier as the key.

This is the ConfigRPC server component, it provides a gRpc API for retrieving partial or total configuration objects from the main value using JSON Path expressions.

JSON Path gRPC API.

service ConfigrpcService {
    rpc findString( FindStringRequest ) returns ( FindStringResponse ) {}
}

message FindStringRequest{
    string key = 1;
    google.protobuf.StringValue jsonPath = 2;
}

message FindStringResponse{
    KeyString kv = 1;
}

message KeyString {
    string key = 1;
    string value = 2;
}

Examples

Given the following configuration data pair

key: /service/data

value:

{
  "environments" : [
    {
      "environment": "TEST", 
      "database": {"host": "10.0.0.79", "user": "sa", "password_key": "test-db-pwd"}, 
      "admin": "sam@svc.com"
     },
    {
      "environment": "STAGING",
      "database": {"host": "10.1.0.237", "user": "sa", "password_key": "staging-db-pwd"},
      "admin": "ana@svc.com"
    }
  ]
}

Query 1: All database properties of 1st environment

key : `/service/data` 

jsonPath : `$.environments[0].database`

Returns: {host=10.0.0.79, user=sa, password_key=test-db-pwd}

Query 2: The host property of the database of 1st environment

key : `/service/data` 

jsonPath : `$.environments[0].database.host`

Returns: 10.0.0.79

Query 3: The property admin of all the database configurations

key : `/service/data` 

jsonPath : `$..admin`

Returns: ["sam@svc.com","ana@svc.com"]

Using gRPC-UI

All admins JsonPath query:

All admins result:

How do I get set up?

• java 11 or newer

Dependencies

This server component depends on the interface submodule configrpc-api.jar

Install the dependency configrpc-api.jar locally, see project for install details

Run

./mvnw spring-boot:run

Note: this project uses Google protocol buffers