Cloud computing, or simply the cloud, has been quite the buzz word in recent years together with cloud service providers like Microsoft Azure, Google Cloud Platform and also – drum roll please – Amazon Web Services, also known as AWS. AWS has been around more than you think, since 2006 if we had to be exact, and in the developers vocabulary it’s really starting to become trendier.
One of the features AWS offers is Simple Notification Service (SNS). The idea behind it is a notification system to push new notifications to all users, or devices, subscribed to it. An SNS Topic is what users subscribe to and is the channel that will enable us to get in touch with them. In this blog post, however, we are going to assume that a topic has already been created and that we know the value of its ARN.
Now let’s focus on how we can send a request to that topic to trigger a new push notification. First thing we need to do is download and install two NuGet packages in our Visual Studio solution.
- AWSSDK.Core
- AWSSDK.SimpleNotificationService
Create a new C# class and paste the following code.
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| using Amazon; | |
| using Amazon.Runtime; | |
| using Amazon.SimpleNotificationService; | |
| using Amazon.SimpleNotificationService.Model; | |
| using System.Net; | |
| class SnsEvents | |
| { | |
| const string AccessKey = "ABCDEFGHIJKLMNOPQRST"; | |
| const string SecretKey = "AbcdeFghiJKlmopqrS39VwXY0Za/1cdEF5I9aC"; | |
| const string SnsArn = "arn:aws:sns:eu-west-1:004673491943:TheNameOfTheSnsTopic"; | |
| static readonly RegionEndpoint Region = RegionEndpoint.EUWest1; //Same region as the ARN above | |
| private static bool publishSnsRequest(string _message) | |
| { | |
| bool success = false; | |
| AWSCredentials credentials; | |
| credentials = new BasicAWSCredentials(AccessKey, SecretKey); | |
| var client = new AmazonSimpleNotificationServiceClient(credentials, Region); | |
| var request = new PublishRequest(SnsArn, _message); | |
| var response = new PublishResponse(); | |
| response = client.Publish(request); | |
| string requestId = response.ResponseMetadata.RequestId; | |
| if (response.HttpStatusCode == HttpStatusCode.OK) { | |
| success = true; | |
| } | |
| return success; | |
| } | |
| } |
Analysing the code we can see that I declared four constant variables which will be used to connect to the SNS Topic. The values of these variables should be provided to you by the person maintaining the SNS. Also, notice the value of the region variable. Same region as specified in SNS’s ARN. Then, using the AWSCredentials object, we create a new credentials instance by supplying the access and secret key in the constructor’s parameters. A new AWS SNS client instance is created and the message that we want to send is published. Afterwards we check the response to make sure that our request was processed successfully.
A quick and straight forward post with a basic implementation of how to publish an SNS Topic from a .NET solution. There are much more options one can implement but this should be enough to get you started.
Until next post,
Bjorn
It's not a bug, it's a feature 