Accessing AWS Secrets Manager from .NET Lambda Functions, Part 2 - Using Async Code
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This is part two in a short series on retrieving secrets from AWS Secrets Manager inside Lambda functions.
In the first post, I showed how to create a secret, and deploy a Lambda function that retrieved the secret. It used a synchronous request to Secrets Manager.
In this post, you will do the same as in the first post, but using a fully async Lambda function.
Steps 1, 2, 3
Follow the steps in the previous post to get the tools, create the secret, and create the Lambda function code.
The code in the Function class will be a little different (don’t forget the using statements from the previous post).
Here is the async version -
1public class Function
2{
3 public async Task<string> FunctionHandler(ILambdaContext context)
4 {
5 string secretName = "my-credentials";
6 string region = "us-east-1";
7
8 var timeout = context.RemainingTime.Subtract(TimeSpan.FromSeconds(3));
9 var cancellationToken = new CancellationTokenSource(timeout);
10
11 return await GetSecretValue(secretName, region, cancellationToken.Token);
12 }
13
14 private async Task<string> GetSecretValue(string secretName, string region, CancellationToken cancellationToken)
15 {
16 IAmazonSecretsManager client = new AmazonSecretsManagerClient(RegionEndpoint.GetBySystemName(region));
17
18 GetSecretValueRequest request = new GetSecretValueRequest(){
19 SecretId = secretName,
20 VersionStage = "AWSCURRENT"
21 };
22
23 try
24 {
25 GetSecretValueResponse response = await client.GetSecretValueAsync(request, cancellationToken);
26 return response.SecretString;
27 }
28 catch (OperationCanceledException oce)
29 {
30 System.Console.WriteLine($"Request timed out, the cancellation token was triggered. {oce.Message}");
31 throw;
32 }
33 catch (Exception ex)
34 {
35 Console.Error.WriteLine("Error: " + ex.Message);
36 throw;
37 }
38 }
39}Steps 4, 5, 6, 7
Follow the steps in the previous post to deploy the function, invoke it, fix the permissions, and invoke it again.
Download full source code.