The Airflow REST API Plugin would help you out here. Once you have followed the instructions for installing the plugin you would just need to hit the following url: http://{HOST}:{PORT}/admin/rest_api/api/v1.0/trigger_dag?dag_id={dag_id}&run_id={run_id}&conf={url_encoded_json_parameters}
, replacing dag_id with the id of your dag, either omitting run_id or specify a unique id, and passing a url encoded json for conf (with any of the parameters you need in the triggered dag).
Here is an example JavaScript function that uses jQuery to call the Airflow api:
function triggerDag(dagId, dagParameters){
var urlEncodedParameters = encodeURIComponent(dagParameters);
var dagRunUrl = "http://airflow:8080/admin/rest_api/api/v1.0/trigger_dag?dag_id="+dagId+"&conf="+urlEncodedParameters;
$.ajax({
url: dagRunUrl,
dataType: "json",
success: function(msg) {
console.log('Successfully started the dag');
},
error: function(e){
console.log('Failed to start the dag');
}
});
}