[feat] /health implementation

[lgrd]

A /heath route exists but it is a fake one in the sense you just know that the service is alive. Create a more sophisticated one :

• Be sure of the io. See [doc] Update administration API specification #34
• Choose the protocol of communication between an administrator and its services: direct (sameProcess) or IPC (newProcess)
• Code it (see next paragrah)
• Update doc (ex. functionalities)
• Update tests

Code

• Create requests/healthRequest.js which is the request part of the interface
• Create responses/healthResponse.js which is the response part of the interface
• Update apis/admin/1.0.0/index.js to handle the request and its parameters. This is where an interface is created (see simple/1.0.0). The interface is send to the administrator. The answer will be generated from the interface received in response to the request interface.
• Update administrator/administrator.js to handle the interface. It will only send it to the serviceManager and wait for the answer
• Update service/serviceManager.js to handle the interface. It will send the interface to each administered service (call to administeredService.computeRequest(request)) and wait for the answers.
• Update each administered service to handle the interface (code computeRequest(request) for each one)
  • sameProcess : call to service.computeAdminRequest(request)
  • newProcess : send a message to the child process
• Update service/service.js to handle the interface for each protocol. It reads the request interface and answers the response interface.
  • code service.computeAdminRequest()
  • find a place to code message reception and call to service.computeAdminRequest()
  • code service.health() to call its source.health()
• Update each source to code source.health()