Created question in FIWARE Q/A platform on 17-05-2016 at 15:05
Please, ANSWER this question AT https://stackoverflow.com/questions/37277048/how-to-make-an-orion-ngsiv2-subscription-that-notifies-cygnus-in-ngsiv1

Question:
How to make an Orion NGSIv2 subscription that notifies cygnus in NGSIv1?

Description:
EDIT 2

curl --include \
--header 'Content-Type: application/json' \
--request POST \
--data-binary '{
"description": "Day subscription",
"subject": {
"entities": [

{ "idPattern": "es-leon-.*", "type": "Event" }

],
"condition": {
"attrs": [
"Title",
"dFlag"
],
"expression":

{ "q": "dFlag>0" }

}
},
"notification": {
"http":

{ "url" : "http://localhost:5050/notify" }

,
"attrs": [
"Title",
"dFlag"
],
"attrsFormat":"legacy"
}
}' \
'http://localhost:1026/v2/subscriptions'

In Orion the subscription register ok (thanks for the tips in the comments) but I'm having the same issue as said in here even though I use "attrsFormat":"legacy"
I'm making something wrong? why orion is not using ngsiv1 to send the notification to cygnus?

The cygnus error trace.

Cygnus shows orion is responding this:

{
"subscriptionId": "574315e77775f31b8d3da719",
"data": [{
"id": "es-leon-0",
"type": "Event",
"Title": {
"type": "none",
"value": "pepe",
"metadata": {}
},
"dFlag": {
"type": "text",
"value": "1",
"metadata": {}
}
}]
}

When it has to respond the lines below to be in ngsiv1:

{
"subscriptionId": "5743178d7775f31b8d3da71a",
"originator": "localhost",
"contextResponses": [{
"contextElement": {
"type": "Event",
"isPattern": "false",
"id": "es-leon-0",
"attributes": [

{ "name": "Title", "type": "text", "value": "pep" }

,

{ "name": "dFlag", "type": "text", "value": "1" }

]
},
"statusCode":

{ "code": "200", "reasonPhrase": "OK" }

}]
}

Original Question

As said in other question :

EDIT: note also that you can use NGSIv2 to create/update entities at
Orion and have notifications in NGSIv1 if you:

Create the subscription using NGSIv1 operations

Create the subscription using NGSIv2 operations with attrsFormat equal to legacy.
Have a look to more detailed information here.

So I made up this subscription:

curl --include \
--header 'Content-Type: application/json' \
--request POST \
--data-binary '{
"description": "Day subscription",
"subject": {
"entities": [

{ "idPattern": "es-leon-.*", "type": "Event" }

],
"condition": {
"attributes": [
"Title",
"dFlag"
],
"expression":

{ "q": "dFlag > 0" }

}
},
"notification":

{ "callback": "http://localhost:5050/notify", "attributes": [ "Title", "dFlag" ] }

}' \
'http://localhost:1026/v1/subscriptions'

but orion don't let me register it throwing this error:

HTTP/1.1 400 Bad Request
Connection: Keep-Alive
Content-Length: 67
Content-Type: application/json
Fiware-Correlator: 2ecdfc74-1c2f-11e6-82d7-000d3a23bf27
Date: Tue, 17 May 2016 12:59:25 GMT

{"error":"BadRequest","description":"no condition attrs specified"}

Is this the way to use legacy attributes so it can work with cygnus with NGSIv2?
Thanks for the help.

EDIT 1:

Following the answer the subscription should be like this: Right?

curl --include \
--header 'Content-Type: application/json' \
--request POST \
--data-binary '{
"description": "Day subscription",
"subject": {
"entities": [

{ "idPattern": "es-leon-.*", "type": "Event" }

],
"condition": {
"attributes": [
"Title",
"dFlag"
],
"expression":

{ "q": "dFlag > 0" }

}
},
"notification": {
"http":

{ "url" : "http://localhost:5050/notify" }

,
"attributes": [
"Title",
"dFlag"
],
"attrsFormat":"legacy"
}
}' \
'http://localhost:1026/v2/subscriptions'

But I'm still getting an error:

HTTP/1.1 100 Continue

HTTP/1.1 400 Bad Request
Connection: Keep-Alive
Content-Length: 67
Content-Type: application/json
Fiware-Correlator: 60a0a1d2-1ddf-11e6-8bd6-000d3a23bf27
Date: Thu, 19 May 2016 16:33:11 GMT

{"error":"BadRequest","description":"no condition attrs specified"}