Schema Registry

The eKuiper command line tools allows you to manage schemas, such as create, show, drop, describe schemas.

Register schema

The command is used for creating a schema. The schema’s definition is specified with JSON format

create schema $schema_type $schema_name $schema_json

Schema can be created by two ways.

• Specify the content inside the command.

Example：

# bin/kuiper create schema protobuf schema1 '{"name": "schema1","content": "message Book {required string title = 1; required int32 price = 2;}"}'

This command create a schema named schema1, the schema content is provided by the content field in the json.

• Specify the schema file path.

Example：

# bin/kuiper create schema protobuf schema1 '{"name": "schema1","file": "file:///tmp/aschema.proto"}'

This command creates a schema named schema1 whose content is provided by file field in the json. The file will be copied into etc/schemas/protobuf and renamed to `schema1.proto.

Parameters

1. schema_type：schema type，the only available type now is protobuf。
2. schema_name：The unique name of the schema which is also the name of the schema file.
3. schema_json：The json to define the schema. It must contain name and file or content field.

Show schemas

The command is used for displaying all schemas defined in the server.

show schemas $schema_type

Example：

# bin/kuiper show schemas protobuf
schema1
schema2

Describe a schema

The command prints the detailed definition of a schema.

describe schema $schema_type $schema_name

Example：

# bin/kuiper describe schema protobuf schema1
{
  "type": "protobuf",
  "name": "schema1",
  "content": "message Book {required string title = 1; required int32 price = 2;}",
  "file": "ekuiper\\etc\\schemas\\protobuf\\schema1.proto"
}

Drop a schema

The command drops the schema. The loaded schema in rules can continue to use until rules restart.

drop schema $schema_type $schema_name

Example：

# bin/kuiper drop schema protobuf schema1
Schema schema1 is dropped.