AWS DynamoDB, S3, SQS を .NET Core で使うコードスニペット集

AWS で比較的使われることが多い DynamoDB, S3, SQS を .NET Core & C# で使う際のコードスニペットをまとめました。

• Amazon DynamoDB
  • Scan (全件取得)
  • Query (検索取得)
  • Query (GSIの検索取得)
  • GetItem (要素の取得)
  • BatchGetItem 処理 (複数要素をまとめて取得)
  • UpdateItem 処理 (追加・更新処理)
  • DeleteItem 処理 (削除処理)
  • BatchWriteItem 処理 (複数要素をまとめて更新)
  • TransactWriteItems (トランザクションでの更新処理)
• Amazon S3
  • アップロード処理
  • ダウンロード処理
  • 署名付きURLの発行
• Amazon SQS
  • SendMessage 処理 (エンキュー)
  • SendMessageBatch 処理 (まとめてのエンキュー)
  • ReceiveMessage 処理 (デキュー)

Amazon DynamoDB

DynamoDBに関するコードスニペットは、AWSSDK.DynamoDBv2パッケージと、以下通りの名前空間の参照とSampleTableItemクラスの定義を使用することを前提としています。

// dotnet add package AWSSDK.DynamoDBv2
using Amazon.DynamoDBv2;
using Amazon.DynamoDBv2.Model;
using Amazon.DynamoDBv2.DataModel;
using Amazon.DynamoDBv2.DocumentModel;

[DynamoDBTable("sample-table")]
class SampleTableItem
{
    [DynamoDBHashKey("pk")]
    public int PartitionKey { get; set; }

    [DynamoDBRangeKey("sk")]
    public string SortKey { get; set; }

    [DynamoDBProperty("prop")]
    public string Property { get; set; }
}

Scan (全件取得)

var client = new AmazonDynamoDBClient();
var context = new DynamoDBContext(client);
var items = await context.ScanAsync<SampleTableItem>(null).GetRemainingAsync();

Query (検索取得)

指定したPartitionKeyの項目をすべて取得

var client = new AmazonDynamoDBClient();
var context = new DynamoDBContext(client);
var partitionKey = 0;
var items = await context.QueryAsync<SampleTableItem>(partitionKey).GetRemainingAsync();

指定したPartitionKeyとSortKeyでの範囲検索

var client = new AmazonDynamoDBClient();
var context = new DynamoDBContext(client);
// PartitionKeyの値が0で、SortKeyがSampleから始まるあるすべてのItemを取得する
var partitionKey = 0;
var sortKeys = new[] { "Sample" };
var items = await context.QueryAsync<SampleTableItem>(partitionKey, QueryOperator.BeginsWith, sortKeys).GetRemainingAsync();

Query (GSIの検索取得)

var client = new AmazonDynamoDBClient();
var context = new DynamoDBContext(client);
const string gsiPartitionKey = "SampleSortKey";
const string indexName = "SampleIndex";
var filter = new QueryFilter("sk", QueryOperator.Equal, gsiPartitionKey);
var config = new QueryOperationConfig
{
    Filter = filter,
    IndexName = indexName
};
var items = await context.QueryAsync<SampleTableItem>(config).GetRemainingAsync();

GSI: Global Secondary Index

GetItem (要素の取得)

var client = new AmazonDynamoDBClient();
var context = new DynamoDBContext(client);
const int partitionKey = 0;
const string sortKey = "SampleSortKey";
var item = await context.LoadAsync<SampleTableItem>(partitionKey, sortKey);

BatchGetItem 処理 (複数要素をまとめて取得)

var client = new AmazonDynamoDBClient();
var context = new DynamoDBContext(client);
var batch = context.CreateBatchGet<SampleTableItem>();
batch.AddKey(0, "SampleSortKey1");
batch.AddKey(0, "SampleSortKey2");
await batch.ExecuteAsync();
var items = batch.Results;

UpdateItem 処理 (追加・更新処理)

var client = new AmazonDynamoDBClient();
var context = new DynamoDBContext(client);
var item = new SampleTableItem
{
    PartitionKey = 0,
    SortKey = "SampleSortKey",
    Property = "Value"
};
await context.SaveAsync(item);

DeleteItem 処理 (削除処理)

var client = new AmazonDynamoDBClient();
var context = new DynamoDBContext(client);
const int partitionKey = 0;
const string sortKey = "SampleSortKey";
await context.DeleteAsync<SampleTableItem>(partitionKey, sortKey);

BatchWriteItem 処理 (複数要素をまとめて更新)

var client = new AmazonDynamoDBClient();
var context = new DynamoDBContext(client);
var batch = context.CreateBatchWrite<SampleTableItem>();
var items = System.Linq.Enumerable.Range(0, 25).Select(i => new SampleTableItem
{
    PartitionKey = 0,
    SortKey = $"SampleSortKey{i}",
    Property = $"Value{i}"
});
batch.AddPutItems(items);
await batch.ExecuteAsync();

TransactWriteItems (トランザクションでの更新処理)

var client = new AmazonDynamoDBClient();
var request = new TransactWriteItemsRequest();
request.TransactItems = new List<TransactWriteItem>();
request.TransactItems.Add(new TransactWriteItem
{
    Put = new Put
    {
        TableName = "sample-table",
        Item = new Dictionary<string, AttributeValue>
        {
            { "pk", new AttributeValue { N = "0" } },
            { "sk", new AttributeValue { S = "SampleSortKey1" } },
            { "prop", new AttributeValue { S = "Value" } }
        }
    }
});
request.TransactItems.Add(new TransactWriteItem
{
    Delete = new Delete
    {
        TableName = "sample-table",
        Key = new Dictionary<string, AttributeValue>
        {
            { "pk", new AttributeValue { N = "0" } },
            { "sk", new AttributeValue { S = "SampleSortKey2" } }
        }
    }
});
await client.TransactWriteItemsAsync(request);

Amazon DynamoDB トランザクション: 仕組み
https://docs.aws.amazon.com/ja_jp/amazondynamodb/latest/developerguide/transaction-apis.html

Amazon S3

S3に関するスニペットはAWSSDK.S3パッケージと以下の名前空間を使用します。

// dotnet add package AWSSDK.S3
using Amazon.S3;
using Amazon.S3.Transfer;

アップロード処理

アップロードするファイルのパスを指定してアップロード

var client = new AmazonS3Client();
var transfer = new TransferUtility(client);

const string bucketName = "sample-bucket";
const string key = "sample-uploaded-file.txt";
const string uploadFilePath = "sample-uploaded-file.txt";
await transfer.UploadAsync(uploadFilePath, bucketName, key);

アップロードするデータのバイナリを指定してアップロード

var client = new AmazonS3Client();
var transfer = new TransferUtility(client);

const string bucketName = "sample-bucket";
const string key = "sample-uploaded-file.txt";
var bytes = System.Text.Encoding.UTF8.GetBytes("Hello S3 !");
using (var stream = new MemoryStream(bytes))
{
    await transfer.UploadAsync(stream, bucketName, key);
}

ダウンロード処理

ダウンロードしてファイルとして保存する

var client = new AmazonS3Client();
var transfer = new TransferUtility(client);

const string bucketName = "sample-bucket";
const string key = "sample-uploaded-file.txt";
const string downloadFilePath = "s3_sample_download.txt";
await transfer.DownloadAsync(downloadFilePath, bucketName, key);

ダウンロードしたファイルをメモリ上で扱う

var client = new AmazonS3Client();

const string bucketName = "sample-bucket";
const string key = "sample-uploaded-file.txt";
var s3Object = await client.GetObjectAsync(bucketName, key);
using (var stream = new StreamReader(s3Object.ResponseStream))
{
    var text = await stream.ReadToEndAsync();
}

署名付きURLの発行

const string bucketName = "sample-bucket";
const string key = "sample-uploaded-file.txt";

var client = new AmazonS3Client();
var request = new Amazon.S3.Model.GetPreSignedUrlRequest
{
    BucketName = bucketName,
    Key = key,
    Verb = HttpVerb.GET,
    Expires = DateTime.UtcNow.AddMinutes(1)
};
var presignedUrl = client.GetPreSignedURL(request);

署名付き URL を使用したオブジェクトのアップロード
https://docs.aws.amazon.com/ja_jp/AmazonS3/latest/dev/PresignedUrlUploadObject.html

Amazon SQS

S3に関するスニペットはAWSSDK.S3パッケージと以下の名前空間を使用します。

// dotnet add package AWSSDK.SQS
using Amazon.SQS;
using Amazon.SQS.Model;

SendMessage 処理 (エンキュー)

var client = new AmazonSQSClient();
const string queueUrl = "https://sqs.region-name.amazonaws.com/0000000000/your-queue-name";
await client.SendMessageAsync(queueUrl, "Hello SQS !");

SendMessageBatch 処理 (まとめてのエンキュー)

var client = new AmazonSQSClient();
const string queueUrl = "https://sqs.region-name.amazonaws.com/0000000000/your-queue-name";
var messages = System.Linq.Enumerable.Range(0, 5).Select(i => new SendMessageBatchRequestEntry
{
    Id = i.ToString(),
    MessageBody = "Hello SQS !! - " + i,
}).ToList();
await client.SendMessageBatchAsync(queueUrl, messages);

ReceiveMessage 処理 (デキュー)

var client = new AmazonSQSClient();
const string queueUrl = "https://sqs.region-name.amazonaws.com/0000000000/your-queue-name";
var receiveMessageRequest = new ReceiveMessageRequest
{
    QueueUrl = queueUrl,
    MaxNumberOfMessages = 10
};
var resp = await client.ReceiveMessageAsync(receiveMessageRequest);
var messages = resp.Messages;