seneca-registry

Seneca service registry (simplistic single instance).

This plugin module provides a simplistic service registry based on a key-value store interface. This is similar to the interface provided by Consul, etcd and Zookeeper. The keys are organized into a tree structure.

IMPORTANT: this plugin does not provide a distributed implementation. It merely provides an message pattern interface and an in-memory implementation, primarily for unit-testing purposes.

This module is a Seneca plugin. For a gentle introduction to Seneca itself, see the senecajs.org site.

Seneca compatibility

Supports Seneca versions 3.x and above.

Support

If you're using this module, feel free to contact me on twitter if you have any questions! :) @rjrodger

Annotated Source Code.

Quick Example

Get and set a key:

require('seneca')()
  .use('registry')
  .start()
  .wait('role:registry,cmd:set,key:color,value:red')
  .wait('role:registry,cmd:get,key:color')
  .step(function(data){
    console.log( data.value ) // == "red"
    return true;
  })
  .end()

Usage

Keys are strings of the form: a/b/c where each / defines a branch of a tree. In simple cases, you can treat keys as simple identifiers and ignore this tree structure. In more complex cases you can use the tree structure as a namespace mechanism. In particular, you can remove and list keys recursively.

require('seneca')()
  .use('registry')
  .start()
 
  .wait('role:registry,cmd:set,key:x,value:1')
  .wait('role:registry,cmd:set,key:x/u,value:2')
  .wait('role:registry,cmd:set,key:x/v,value:3')
  .wait('role:registry,cmd:set,key:x/v/y,value:4')
 
  .wait('role:registry,cmd:list,key:x')
  .step(function(data){
    console.log( data.keys ) // == [ 'u', 'v' ]
    return true;
  })
 
  .wait('role:registry,cmd:list,key:x,recurse:true')
  .step(function(data){
    console.log( data.keys ) // == [ 'u', 'v', 'v/y' ]
    return true;
  })
 
  .end()

Action Patterns

role:registry, cmd:set

Set the value of a key.

Parameters:

• key: string; key name
• value: any; key value; serialized to JSON

Response: none.

role:registry, cmd:get

Get the value of a key.

Parameters:

• key: string; key name

Response:

• value: any; key value; deserialized from JSON

role:registry, cmd:list

List the sub keys of a key, under the tree structure, with / as branch separator.

Parameters:

• key: string; key name or partial prefix name of key to query
• recurse: boolean, optional, default: false; if true, list all sub keys, if false, list only child keys

Response:

• keys: array[string]; keys in breadth first order

role:registry, cmd:remove

Remove the value of a key, and optionally all sub keys.

Parameters:

• key: string; key name or partial prefix name of key to remove
• recurse: boolean, optional, default: false; if true, remove value and all sub keys, if false, remove only value

Response: none