internal TheScheduledLambdaStack(Construct scope, string id, IStackProps props = null) : base(scope, id, props)
{
// DynamoDB Table
_dynamoDbTable = new DynamoDB.Table(this, "RequestTable", new DynamoDB.TableProps
{
PartitionKey = new DynamoDB.Attribute
{
Name = "requestid", Type = DynamoDB.AttributeType.STRING
},
RemovalPolicy = RemovalPolicy.DESTROY
});
// Create the Lambda function we want to run on a schedule
_functionScheduled = new Lambda.Function(this, "ScheduledLambda", new Lambda.FunctionProps
{
Runtime = Lambda.Runtime.NODEJS_12_X, // execution environment
Handler = "index.handler", // file is "index", function is "handler"
Code = Lambda.Code.FromAsset("lambda_fns"), // code loaded from the "lambda_fns" directory,
Environment = new Dictionary <string, string>
{
{ "TABLE_NAME", _dynamoDbTable.TableName }
}
});
// Allow our lambda fn to write to the table
_dynamoDbTable.GrantReadWriteData(_functionScheduled);
// Create EventBridge rule that will execute our Lambda every 2 minutes
_ruleScheduled = new Events.Rule(this, "scheduledLambda-schedule", new Events.RuleProps
{
Schedule = Events.Schedule.Expression("rate(2 minutes)")
});
// Set the target of our EventBridge rule to our Lambda function
_ruleScheduled.AddTarget(new EventsTarget.LambdaFunction(_functionScheduled));
}
internal TheScalableWebhookStack(Construct scope, string id, IStackProps props = null) : base(scope, id, props)
{
/*
* DynamoDB Table
* This is standing in for what is RDS on the diagram due to simpler/cheaper setup
*/
_dynamoDbTable = new DynamoDB.Table(this, "Messages", new DynamoDB.TableProps
{
PartitionKey = new DynamoDB.Attribute {
Name = "id", Type = DynamoDB.AttributeType.STRING
}
});
/*
* Queue Setup
*/
_queueRds = new SQS.Queue(this, "RDSPublishQueue", new SQS.QueueProps
{
VisibilityTimeout = Duration.Seconds(300)
});
/*
* Lambdas
* Both publisher and subscriber from pattern
*/
/*
* defines an AWS Lambda resource to publish to our sqs_queue
*/
_functionPublish = new Lambda.Function(this, "SQSPublishLambdaHandler", new Lambda.FunctionProps
{
Runtime = Lambda.Runtime.NODEJS_12_X, // execution environment
Handler = "lambda.handler", // file is "lambda", function is "handler"
Code = Lambda.Code.FromAsset("lambda_fns/publish"), // code loaded from the "lambda_fns/publish" directory
Environment = new Dictionary <string, string>
{
{ "queueURL", _queueRds.QueueUrl }
}
});
_queueRds.GrantSendMessages(_functionPublish);
/*
* defines an AWS Lambda resource to pull from our sqs_queue
*/
_functionSubscribe = new Lambda.Function(this, "SQSSubscribeLambdaHandler", new Lambda.FunctionProps
{
Runtime = Lambda.Runtime.NODEJS_12_X, // execution environment
Handler = "lambda.handler", // file is "lambda", function is "handler"
Code = Lambda.Code.FromAsset("lambda_fns/subscribe"), // code loaded from the "lambda_fns/subscribe" directory
Environment = new Dictionary <string, string>
{
{ "queueURL", _queueRds.QueueUrl },
{ "tableName", _dynamoDbTable.TableName }
},
ReservedConcurrentExecutions = 2 // throttle lambda to 2 concurrent invocations
});
_queueRds.GrantConsumeMessages(_functionSubscribe);
_functionSubscribe.AddEventSource(new LambdaEvents.SqsEventSource(_queueRds));
_dynamoDbTable.GrantReadWriteData(_functionSubscribe);
/**
* API Gateway Proxy
* Used to expose the webhook through a URL
*
* defines an API Gateway REST API resource backed by our "sqs_publish_lambda" function.
*/
new APIG.LambdaRestApi(this, "Endpoint", new APIG.LambdaRestApiProps
{
Handler = _functionPublish
});
}
