How do I check whether a mobile device has already been registered - ruby

Question

I'm using the Amazon AWS Ruby SDK for Amazon SNS but I'm having some trouble with devices already being registered. Sometimes when a device gets registered again I get an error like AWS::SNS::Errors::InvalidParameter Invalid parameter: Token Reason: Endpoint arn:aws:sns:us-east-1:**** already exists with the same Token, but different attributes.. How do I check whether an endpoint already exists and more importantly, how do I get the endpoint for a given token?

Answer 1

Credit to BvdBijl's idea, I made an extension method to delete the existing one if found and then add it.
using System;
using System.Text.RegularExpressions;
using Amazon.SimpleNotificationService;
using Amazon.SimpleNotificationService.Model;
namespace Amazon.SimpleNotificationService
{
public static class AmazonSimpleNotificationServiceClientExtensions
{
private const string existingEndpointRegexString = "Reason: Endpoint (.+) already exists with the same Token";
private static Regex existingEndpointRegex = new Regex(existingEndpointRegexString);
public static CreatePlatformEndpointResponse CreatePlatformEndpointIdempotent(
this AmazonSimpleNotificationServiceClient client,
CreatePlatformEndpointRequest request)
{
try
{
var result = client.CreatePlatformEndpoint(request);
return result;
}
catch (AmazonSimpleNotificationServiceException e)
{
if (e.ErrorCode == "InvalidParameter")
{
var match = existingEndpointRegex.Match(e.Message);
if (match.Success) {
string arn = match.Groups[1].Value;
client.DeleteEndpoint(new DeleteEndpointRequest
{
EndpointArn = arn,
});
return client.CreatePlatformEndpoint(request);
}
}
throw;
}
}
}
}

Answer 2

It looks like amazone resolved this issue.
I'm using RoR and used to have same problem when trying to register and existing GCM code I got an error message saying
"AWS::SNS::Errors::InvalidParameter Invalid parameter: Token Reason: Endpoint arn:aws:sns:us-east-1:**** already exists with the same Token, but different attributes."
although I used same (empty) attributes. Now when I send an existing GCM code (with same attributes as the original one) I get the endpoint arn and not the error message.

Answer 3

ListEndpointsByPlatformApplication only return 100 endpoints, you have to use nextToken to get more. Here is my implementation.
public void deleteEndpoint(string token, string PlatformApplicationArn)
{
ListEndpointsByPlatformApplicationRequest listRequest = new ListEndpointsByPlatformApplicationRequest();
listRequest.PlatformApplicationArn = PlatformApplicationArn;
Logger.Info("Deleting endpoint with token -> " + token);
var list = snsClient.ListEndpointsByPlatformApplication(listRequest);
do
{
foreach (var x in list.Endpoints.Where(x => x.Attributes["Token"] == token))
{
snsClient.DeleteEndpoint(new DeleteEndpointRequest() { EndpointArn = x.EndpointArn });
Logger.Info("Endpoint removed-> " + x.EndpointArn);
return;
}
listRequest.NextToken = list.NextToken;
list = snsClient.ListEndpointsByPlatformApplication(listRequest);
}
while (list.NextToken != null);
}