# AWS Secrets Manager Caching Client for .NET

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The AWS Secrets Manager caching client enables in-process caching of secrets for .NET applications.

## Required Prerequisites

To use this client, you must have:

* A .NET project with one of the following:
    * .NET Framework 4.6.2 or higher
    * .NET Standard 2.0 or higher

* An Amazon Web Services (AWS) account to access secrets stored in AWS Secrets Manager and use AWS SDK for .NET.

    * **To create an AWS account**, go to [Sign In or Create an AWS Account](https://portal.aws.amazon.com/gp/aws/developer/registration/index.html) and then choose **I am a new user.** Follow the instructions to create an AWS account.

    * **To create a secret in AWS Secrets Manager**, go to [Creating Secrets](https://docs.aws.amazon.com/secretsmanager/latest/userguide/manage_create-basic-secret.html) and follow the instructions on that page.

    * **To download and install the AWS SDK for .NET**, go to [Installing the AWS SDK for .NET](https://aws.amazon.com/sdk-for-net/) in the AWS SDK for .NET documentation and then follow the instructions on that page.

## Download

You can get the latest release from `Nuget`:

```xml
<ItemGroup>
     <PackageReference Include="AWSSDK.SecretsManager.Caching" Version="1.0.6" />
</ItemGroup>
```

## Getting Started

The following code sample demonstrates how to start using the caching client:

```cs
using System;
using Amazon.SecretsManager.Extensions.Caching.SecretsManagerCache;

namespace LambdaExample {
    public class CachingExample 
    {
        private SecretsManagerCache cache = new SecretsManagerCache();
        private const String MySecretName = "MySecret";

        public async Task<Response> FunctionHandlerAsync(String input, ILambdaContext context)
        {
            String MySecret = await cache.GetSecretString(MySecretName);
            ...
        }
    }
}
```

* After instantiating the cache, retrieve your secret using `GetSecretString` or `GetSecretBinary`. 
* On successive retrievals, the cache will return the cached copy of the secret. 
* Learn more about [AWS Lambda Function Handlers in C#](https://docs.aws.amazon.com/lambda/latest/dg/dotnet-programming-model-handler-types.html).

### Cache Configuration

You can configure the `SecretCacheConfiguration` object with the following parameters:
* `CacheItemTTL` - The TTL of a Cache item in milliseconds. The default value is `3600000` ms, or 1 hour.
* `MaxCacheSize` - The maximum number of items the Cache can contain before evicting using LRU. The default value is `1024`.
* `VersionStage` - The Version Stage the Cache will request when retrieving secrets from Secrets Manager. The default value is `AWSCURRENT`.
* `Client` - The Secrets Manager client to be used by the Cache. The default value is `null`, which causes the Cache to instantiate a new Secrets Manager client.
* `CacheHook` - An implementation of the ISecretCacheHook interface. The default value is `null`.

## Getting Help
We use GitHub issues for tracking bugs and caching library feature requests and have limited bandwidth to address them. Please use these community resources for getting help:
* Ask a question on [Stack Overflow](https://stackoverflow.com/) and tag it with [aws-secrets-manager](https://stackoverflow.com/questions/tagged/aws-secrets-manager).
* Open a support ticket with [AWS Support](https://console.aws.amazon.com/support/home#/).
* If it turns out that you may have found a bug, please [open an issue](https://github.com/aws/aws-secretsmanager-caching-csharp/issues/new). 

## License

This library is licensed under the Apache 2.0 License.