问题
I'm trying to use Orion CB as Contex Provider for an IoT Agent in which I have registred a device with lazy attributes only.
On the IoT Agent I need to handle updateContext requests so I did a handler for these requests like this:
iotAgentLib.setDataUpdateHandler(updateContextHandler);
And in the updateContextHandler function I have only one instruction:
console.log(attributes);
In order to see if all the values I want to update have been received correctly.
Now if I do an update on one of the attributes of the entity represented by the device:
curl -i -X POST \
-H "fiware-service:service1" \
-H "fiware-servicepath:/subservice1" \
-H "X-Auth-Token:wNRwDwqYlLoLD8U9sFkTAEE6PfYMbQ" \
-H "Content-Type:application/json" \
-d \
'{
"contextElements": [
{
"id": "ncc_estimate",
"attributes": [
{
"name": "arrival",
"type": "string",
"value": "some_value"
}
]
}
],
"updateAction": "UPDATE"
} ' \
'http://{orion_address}/v1/updateContext'
What I see on the IoT Agent output console is:
time=2018-01-09T08:14:59.539Z | lvl=DEBUG | corr=2f4fdb0c-f515-11e7-86b2-0242ac110003 | trans=6ac5c35d-d7bf-419c-8f64-bc843b991d47 | op=IoTAgentNGSI.GenericMiddlewares | srv=service1 | subsrv=/subservice1 | msg=Body:
{
"contextElements": [
{
"type": "nccestimate",
"isPattern": "false",
"id": "ncc_estimate",
"attributes": [
{
"name": "arrival",
"type": "string",
"value": ""
}
]
}
],
"updateAction": "UPDATE"
}
Where as you can see the value field is empty, as I can also see from the console.log() output in the UpdateHandler function that is:
[ { name: 'arrival', type: 'string', value: '' } ]
It seems that Orion is deleting the value before sending it to the IoT Agent. What could be the problem? Am I wrong doing something?
edit:
Here is the response for the call to: /v1/registry/contextEntities/ncc_estimate
{"contextRegistrationResponses":[
{"contextRegistration":
{"entities":[
{
"type":"nccestimate",
"isPattern":"false",
"id":"ncc_estimate"
}
],
"attributes":[
{
"name":"transport_type",
"type":"string",
"isDomain":"false"
},
{
"name":"arrival",
"type":"string",
"isDomain":"false"
}
],
"providingApplication":"http://192.168.199.151:4044"}
}
]}
edit2:
This is what Orion is sending to the iot agent when performing the updateContext operation described before:
POST //updateContext HTTP/1.1
User-Agent: orion/1.10.0-next libcurl/7.19.7
Host: 192.168.199.151:4044
fiware-service: service1
Fiware-ServicePath: /subservice1
X-Auth-Token: M62UkJc7yKX5aQwaHrsODfIrV4Ou85
Accept: application/json
Content-length: 169
Content-type: application/json; charset=utf-8
Fiware-Correlator: 42561e9a-f615-11e7-8610-0242ac110003
{"contextElements":[{"type":"nccestimate","isPattern":"false","id":"ncc_estimate","attributes":[{"name":"arrival","type":"string","value":""}]}],"updateAction":"UPDATE"}
As you can see the "value" field for the attribute is empty. I'm using Orion version 1.10.0 and iot agent node lib version 2.5.1.
回答1:
I have done the following test using CB same version as yours (i.e. 1.10.0)
First, create a registration as the one that IOTA would create:
(curl -s -S localhost:1026/v1/registry/registerContext -H "fiware-service:service1" -H "fiware-servicepath:/subservice1" -H 'Content-Type: application/json' -d @- | python -mjson.tool) <<EOF
{
"contextRegistrations": [
{
"entities": [
{
"type": "nccestimate",
"isPattern": "false",
"id": "ncc_estimate"
}
],
"attributes": [
{
"name": "transport_type",
"type": "string",
"isDomain": "false"
},
{
"name": "arrival",
"type": "string",
"isDomain": "false"
}
],
"providingApplication": "http://localhost:4044"
}
],
"duration": "P1M"
}
EOF
Next, check that it is exactly the same registration shown in the question post (except by the providingApplication, that points to localhost):
curl localhost:1026/v1/registry/contextEntities/ncc_estimate -s -S -H "fiware-service:service1" -H "fiware-servicepath:/subservice1" -H 'Accept: application/json' | python -mjson.tool
which response is
{
"contextRegistrationResponses": [
{
"contextRegistration": {
"attributes": [
{
"isDomain": "false",
"name": "transport_type",
"type": "string"
},
{
"isDomain": "false",
"name": "arrival",
"type": "string"
}
],
"entities": [
{
"id": "ncc_estimate",
"isPattern": "false",
"type": "nccestimate"
}
],
"providingApplication": "http://localhost:4044"
}
}
]
}
Next, run nc process at localhost on providingApplication port.
nc -l -p 4044
Once the setup is done, let's test first with an update based on the one in the question.
curl -s -S -X POST http://localhost:1026/v1/updateContext -H "fiware-service:service1" -H "fiware-servicepath:/subservice1" -H "Content-Type:application/json" -d @- <<EOF
{
"contextElements": [
{
"id": "ncc_estimate",
"attributes": [
{
"name": "arrival",
"type": "string",
"value": "some_value"
}
]
}
],
"updateAction": "UPDATE"
}
EOF
In this case, Orion doesn't recognized the registration and returns a Not Found response:
{
"contextResponses": [{
"contextElement": {
"type": "",
"isPattern": "false",
"id": "ncc_estimate",
"attributes": [{
"name": "arrival",
"type": "string",
"value": ""
}]
},
"statusCode": {
"code": "404",
"reasonPhrase": "No context element found",
"details": "ncc_estimate"
}
}]
}
In other words, Orion is not forwarding the response. I don't know why in your case is forwarded and leaves a trace in IOTA log file.
Next test uses the same request but adding a type field for the entity.
curl -s -S -X POST http://localhost:1026/v1/updateContext -H "fiware-service:service1" -H "fiware-servicepath:/subservice1" -H "Content-Type:application/json" -d @- <<EOF
{
"contextElements": [
{
"id": "ncc_estimate",
"type": "nccestimate",
"attributes": [
{
"name": "arrival",
"type": "string",
"value": "some_value"
}
]
}
],
"updateAction": "UPDATE"
}
EOF
In this case, the request is forwarded and I get this in the nc terminal.
POST //updateContext HTTP/1.1
User-Agent: orion/1.10.0 libcurl/7.38.0
Host: localhost:4044
fiware-service: service1
Fiware-ServicePath: /subservice1
Accept: application/json
Content-length: 179
Content-type: application/json; charset=utf-8
Fiware-Correlator: 42e75f8a-fa0d-11e7-93f1-000c29173617
{"contextElements":[{"type":"nccestimate","isPattern":"false","id":"ncc_estimate","attributes":[{"name":"arrival","type":"string","value":"some_value"}]}],"updateAction":"UPDATE"}
Note the some_value in the response. Orion seems to be progressing correctly the request in this case.
EDIT: according to user's feedback, entity type solved the problem. We are highlighting it in the documentation regarding Context Providers:
You should include entity type in the query/update in order for the ContextBroker to be able to forward to Context Providers
来源：https://stackoverflow.com/questions/48163972/orion-cb-doesnt-update-lazy-attributes-on-iot-agent