Runtime exception when updating shadow

[rysotope]

Runtime exception when updating shadow

[ridomin]

Hi @rysotope, unfortunately I'm having issues with my AWS account and I cannot run the AWS Shadow Client anymore.

Last time I tried the ShadowBinders :
Sample:
https://github.com/iotmodels/MQTTnet.Extensions.MultiCloud/blob/master/samples/aws-sample/Device.cs

Tests:
https://github.com/iotmodels/MQTTnet.Extensions.MultiCloud/blob/master/tests/MQTTnet.Extensions.MultiCloud.IntegrationTests/AwsClientFixture.cs#L22

Did any of these work for you?

[rysotope]

Hi @ridomin

I tried the unit test as you suggested, and was able to recreate the issue.

GetShadowAsync() returned:
{"state":{"desired":{"welcome":"aws-iot"},"reported":{"welcome":"aws-iot"}},"metadata":{"desired":{"welcome":{"timestamp":1675697222}},"reported":{"welcome":{"timestamp":1675697222}}},"version":1,"timestamp":1675697681}

Here's the stack trace:
System.InvalidOperationException
HResult=0x80131509
Message=Nullable object must have a value.
Source=System.Private.CoreLib
StackTrace:
at System.ThrowHelper.ThrowInvalidOperationException_InvalidOperation_NoValue()
at System.Nullable1.get_Value() at MQTTnet.Extensions.MultiCloud.AwsIoTClient.ShadowSerializer.ToBytes[T](T payload, String name, Nullable1 version) in C:\Source\GitHub\MQTTnet.Extensions.MultiCloud\src\MQTTnet.Extensions.MultiCloud.AwsIoTClient\ShadowSerializer.cs:line 33
at MQTTnet.Extensions.MultiCloud.AwsIoTClient.ShadowRequestResponseBinder.d__11.MoveNext() in C:\Source\GitHub\MQTTnet.Extensions.MultiCloud\src\MQTTnet.Extensions.MultiCloud.AwsIoTClient\ShadowRequestResponseBinder.cs:line 109
at MQTTnet.Extensions.MultiCloud.IntegrationTests.AwsClientFixture.d__1.MoveNext() in C:\Source\GitHub\MQTTnet.Extensions.MultiCloud\tests\MQTTnet.Extensions.MultiCloud.IntegrationTests\AwsClientFixture.cs:line 27

This exception was originally thrown at this call stack:
[External Code]
MQTTnet.Extensions.MultiCloud.AwsIoTClient.ShadowSerializer.ToBytes(T, string, int?) in ShadowSerializer.cs
MQTTnet.Extensions.MultiCloud.AwsIoTClient.ShadowRequestResponseBinder.UpdateShadowAsync(object, System.Threading.CancellationToken) in ShadowRequestResponseBinder.cs
MQTTnet.Extensions.MultiCloud.IntegrationTests.AwsClientFixture.GetUpdateShadow() in AwsClientFixture.cs

[ridomin]

I'm sorry but I'm not able to access my AWS resources for testing anymore :(

I tried to fix this issue here 7e0e1ae, let me know if it works for you before merging into dev

[rysotope]

Your changes worked :) Thank you!

Returned state after the test:
{"state":{"desired":{"welcome":"aws-iot"},"reported":{"welcome":"aws-iot","name":"rido3"}},"metadata":{"desired":{"welcome":{"timestamp":1675697222}},"reported":{"welcome":{"timestamp":1675697222},"name":{"timestamp":1675707985}}},"version":2,"timestamp":1675708098}

[ridomin]

thanks for checking, I'm merging into dev and it will be fixed by the next release.

I'd love to learn more about your use case. Are you planning to take a dependency on this project packages to interact with AWS shadows? or just borrow the code?

I'm asking because I was thinking to remove AWS support in future versions.

[rysotope]

I've been working on a PoC for my company involving your libraries.
Originally we had thought to leverage something in-house like Mosquitto but pivoted to AWS.
To be honest, I'm not sure we have a use case for shadows, I would probably leverage some other mechanism for retained/desired settings vs the AWS implementation.

[ridomin]

The Broker client implements reported/desired using retained messages, that might be helpful.

https://github.com/iotmodels/MQTTnet.Extensions.MultiCloud/blob/master/src/MQTTnet.Extensions.MultiCloud.BrokerIoTClient/WritableProperty.cs

Beyond that, is there anything else you need? if not, can you close this issue?

[rysotope]

Thank you for your support!