Eclipse Ditto - Create a MQTT Connection - fails with invalid json 400 response - json

Question

Establishing a connection to an MQTT 3.1.1 endpoint following the description here and
the Operating Devops Commands end up in an invalid json 400 response. Even the example MQTT-Bidirectional gets refused with a 400. So this is why i am posting this question here to get hints what i am currently doing wrong and what i can do to get it right to help others running in the same issue. Here is my curl request:
gd#gd:~/ditto/mosquitto$ curl -X POST 'http://{ditto-url}/devops/piggyback/connectivity?timeout=10000' -u devops:foobar -H 'Content-Type: application/json' -d createMQTT_connection.json
{"status":400,"error":"json.invalid","message":"Failed to parse JSON string 'createMQTT_connection.json'!","description":"Check if the JSON was valid (e.g. on https://jsonlint.com) and if it was in required format."}
The hint to check my json file gives back that my json is valid.
Here is how my json file currently looks like:
{
"targetActorSelection": "/system/sharding/connection",
"headers": {
"aggregate": false
},
"piggybackCommand": {
"type": "connectivity.commands:createConnection",
"connection": {
"id": "mqtt-example-connection-123",
"name": "mmqtt-example-connection-123",
"connectionType": "mqtt",
"connectionStatus": "open",
"failoverEnabled": true,
"uri": "tcp://{mqtt-broker-url}:1883",
"sources": [
{
"addresses": [
"{ditto-url}/#"
],
"authorizationContext": ["nginx:ditto"],
"qos": 0,
"filters": []
}
],
"targets": [
{
"address": "{ditto-url}/{{ thing:id }}",
"topics": [
"_/_/things/twin/events"
],
"authorizationContext": ["nginx:ditto"],
"qos": 0
}
]
}
}
}
Someone got an idea why this json is not valid?
Thanks for the support and hints to solve this issue!
[EDIT]
First of all a "-f" makes more sense for the curl request:
curl -X POST -u devops:foobar 'http://{ditto-url}:8080/devops/piggyback/connectivity?timeout=10000' -f createMQTT_connection_1.json
curl: (22) The requested URL returned error: 400 Bad Request
curl: (6) Could not resolve host: createMQTT_connection_1.json
Second here the update json (with the result shown above)
{
"targetActorSelection": "/system/sharding/connection",
"headers": {
"aggregate": false
},
"piggybackCommand": {
"type": "connectivity.commands:createConnection",
"connection": {
"id": "mqtt-example-connection-123",
"connectionType": "mqtt",
"connectionStatus": "open",
"failoverEnabled": true,
"uri": "tcp://{MQTT-Broker-url}:1883",
"sources": [{
"addresses": ["ditto-tutorial/#"],
"authorizationContext": ["nginx:ditto"],
"qos": 0,
"filters": []
}],
"targets": [{
"address": "ditto-tutorial/{{ thing:id }}",
"topics": [
"_/_/things/twin/events",
"_/_/things/live/messages"
],
"authorizationContext": ["nginx:ditto"],
"qos": 0
}]
}
}
}

Answer 1

I think the problem you face is curl related.
Please have a look here on how to send json data from a file: https://stackoverflow.com/a/18614411/5058051
Seems the # is missing in your case when specifying the file location.