serviceDiscovery IDD
generic_mqtt & generic_mqtts
Overview
This page describes the generic_mqtt and generic_mqtts service interface of serviceDiscovery, which enables both application and Core/Support systems to register and revoke their service instances to/from the Local Cloud. It also enables to lookup for service instances. Service and service instance representation is mandatory for the base functionalities of a Local Cloud therefore it is an integral part of the implementation of the requirements in ServiceRegistry Core System. An example of this interaction is when a provider registers its service instances to offer them to other systems in the Local Cloud. To enable other systems to use, to consume it, this service needs to be offered through the ServiceRegistry. It’s implemented using protocol, encoding as stated in the following tables:
generic_mqtt
Profile type | type | Version |
---|---|---|
Transfer protocol | MQTT | 3.1 and 3.1.1 |
Data encryption | N/A | - |
Encoding | JSON | RFC 8259 |
Compression | N/A | - |
generic_mqtts
Profile type | type | Version |
---|---|---|
Transfer protocol | MQTT | 3.1 and 3.1.1 |
Data encryption | TLS | - |
Encoding | JSON | RFC 8259 |
Compression | N/A | - |
Hereby the Interface Design Description (IDD) is provided to the serviceDiscovery – Service Description. For further details about how this service is meant to be used, please consult that document.
Interface Description
register
The service operation request requires an MQTTRequestTemplate JSON encoded message in which the authentication is a proper identity info and the payload is a ServiceRegistrationRequest.
Topic: arrowhead/serviceregistry/service-discovery/register
{
"traceId": "<trace-id>",
"authentication": "<authentication-data>",
"responseTopic": "<response-topic>",
"qosRequirement": <0|1|2>,
"payload": {
"serviceDefinitionName": "kelvinInfo",
"version": "",
"expiresAt": "2030-01-01T00:00:00Z",
"metadata": {
"marginOfError": 0.5
},
"interfaces": [
{
"templateName": "generic_http",
"protocol": "http",
"policy": "NONE",
"properties": {
"accessAddresses": ["192.168.56.116", "tp2.greenhouse.com"],
"accessPort": 8080,
"basePath": "/kelvin",
"operations": {"query-temperature": { "method": "GET", "path": "/query"} }
}
}
]
}
}
The service operation responds with an MQTTResponseTemplate JSON encoded message in which the status code is 200
if called successfully. The response template payload is a ServiceRegistrationResponse.
{
"status": 200,
"traceId": "<trace-id>",
"receiver": "<receiver-system-identifier>",
"payload": {
"instanceId": "TemperatureProvider1|kelvinInfo|1.0.0",
"provider": {
"name": "TemperatureProvider1",
"metadata": {
"type": "temperature",
"scales": [
"kelvin",
"celsius"
],
"customizable": false
},
"version": "2.1.0",
"addresses": [
{
"type": "HOSTNAME",
"address": "tp1.greenhouse.com"
},
{
"type": "IPV4",
"address": "192.168.66.1"
}
],
"createdAt": "2025-03-09T18:03:26Z",
"updatedAt": "2025-03-09T18:03:26Z"
},
"serviceDefinition": {
"name": "kelvinInfo",
"createdAt": "2025-03-16T23:31:20Z",
"updatedAt": "2025-03-16T23:31:20Z"
},
"version": "1.0.0",
"expiresAt": "2030-01-01T00:00:00Z",
"metadata": {
"marginOfError": 0.5
},
"interfaces": [
{
"templateName": "generic_http",
"protocol": "http",
"policy": "NONE",
"properties": {
"accessAddresses": [
"192.168.56.116",
"tp2.greenhouse.com"
],
"accessPort": 8080,
"operations": {
"query-temperature": {
"path": "/query",
"method": "GET"
}
},
"basePath": "/kelvin"
}
}
],
"createdAt": "2025-03-16T23:34:17.785249400Z",
"updatedAt": "2025-03-16T23:34:17.785249400Z"
}
}
The error codes are 400
if the request is malformed, 401
if the requester authentication was unsuccessful,
403
if the authenticated requester has no permission and
500
if an unexpected error happens. In these cases the response template payload is an
ErrorResponse JSON.
{
"status": 400,
"traceId": "<trace-id>",
"receiver": "temp-provider",
"payload": {
"errorMessage": "System not exists: TempProvider",
"errorCode": 400,
"exceptionType": "INVALID_PARAMETER",
"origin": "arrowhead/serviceregistry/service-discovery/register"
}
lookup
The service operation request requires an MQTTRequestTemplate JSON encoded message in which the authentication is a proper identity info. The MQTTRequestTemplate can contain an optional parameter with the key "verbose" and a Boolean value. If verbose is true, detailed device and system information also returns (only if the provider supports it). The payload of the MQTTRequestTemplate is a ServiceLookupRequest.
Topic: arrowhead/serviceregistry/service-discovery/lookup
{
"traceId": ""<trace-id>",
"authentication": "<authentication-data>",
"responseTopic": "<response-topic>",
"qosRequirement": <0|1|2>,
"params": {"verbose": false},
"payload": {
"instanceIds": [
],
"providerNames": [
"TemperatureProvider1"
],
"serviceDefinitionNames": [
"kelvinInfo"
],
"versions": [
"1.0.0"
],
"alivesAt": "",
"metadataRequirementsList": [
],
"interfaceTemplateNames": [
],
"interfacePropertyRequirementsList": [
],
"policies": [
]
}
}
The service operation responds with an MQTTResponseTemplate JSON encoded message in which the status code is 200
if called successfully. The response template payload is a ServiceLookupResponse.
{
"status": 200,
"traceId": "<trace-id>",
"receiver": "<receiver-system-identifier>",
"payload": {
"entries": [
{
"instanceId": "TemperatureProvider1|kelvinInfo|1.0.0",
"provider": {
"name": "TemperatureProvider1",
"metadata": {
"type": "temperature",
"scales": [
"kelvin",
"celsius"
],
"customizable": false
},
"version": "2.1.0",
"createdAt": "2025-03-09T18:03:26Z",
"updatedAt": "2025-03-09T18:03:26Z"
},
"serviceDefinition": {
"name": "kelvinInfo",
"createdAt": "2025-03-16T23:31:20Z",
"updatedAt": "2025-03-16T23:31:20Z"
},
"version": "1.0.0",
"expiresAt": "2030-01-01T00:00:00Z",
"metadata": {
"marginOfError": 0.5
},
"interfaces": [
{
"templateName": "generic_http",
"protocol": "http",
"policy": "NONE",
"properties": {
"accessAddresses": [
"192.168.56.116",
"tp2.greenhouse.com"
],
"accessPort": 8080,
"operations": {
"query-temperature": {
"path": "/query",
"method": "GET"
}
},
"basePath": "/kelvin"
}
}
],
"createdAt": "2025-03-16T23:34:18Z",
"updatedAt": "2025-03-16T23:34:18Z"
}
],
"count": 1
}
}
The error codes are, 400
if the request is malformed, 401
if the requester authentication was unsuccessful, 403
if the authenticated requester has no permission and 500
if an unexpected error happens. In these cases the response template payload is an
ErrorResponse JSON.
{
"status": 400,
"traceId": "trace1",
"receiver": "<receiver-system-identifier>",
"payload": {
"errorMessage": "One of the following filters must be used: 'instanceIds', 'providerNames', 'serviceDefinitionNames'",
"errorCode": 400,
"exceptionType": "INVALID_PARAMETER",
"origin": "arrowhead/serviceregistry/service-discovery/lookup"
}
}
revoke
The service operation request requires an MQTTRequestTemplate JSON encoded message in which the authentication is a proper identity info and the payload is a ServiceInstanceID. This is a unique identifier of the service instance to be deleted.
Topic: arrowhead/serviceregistry/service-discovery/revoke
{
"traceId": "<trace-id>",
"authentication": "<authentication-data>",
"responseTopic": "<response-topic>",
"qosRequirement": <0|1|2>,
"payload": "TemperatureProvider1|kelvinInfo|1.0.0"
}
The service operation responds with an MQTTResponseTemplate JSON encoded message in which the status code is 200
if called successfully and an existing service instance entity was removed and 204
if no matching entity was found.
{
"status": 200,
"traceId": "<trace-id>",
"receiver": "TemperatureProvider1",
"payload": ""
}
The error codes are, 400
if the request is malformed, 401
if the requester authentication was unsuccessful, 403
if the authenticated requester has no permission and 500
if an unexpected error happens. In these cases the response template payload is an
ErrorResponse JSON.
{
"status": 403,
"traceId": "<trace-id>",
"receiver": "<receiver-system-identifier>",
"payload": {
"errorMessage": ""Revoking other systems' service is forbidden"",
"errorCode": 403,
"exceptionType": "FORBIDDEN",
"origin": "arrowhead/serviceregistry/service-discovery/revoke"
}
}