Amazon EventBridge rule cannot trigger a Lambda Function

Question

Using the .Net AWSSDK.EventBridge I created a rule:

var client = new AmazonEventBridgeClient();
string ruleName = "SomeRule";
var putRuleRequest = new Amazon.EventBridge.Model.PutRuleRequest()
{
  Name = ruleName,
  ScheduleExpression = "rate(10 minutes)",                
  State = RuleState.ENABLED
}

await client.PutRuleAsync(putRuleRequest);

var target = new Amazon.EventBridge.Model.Target();
target.Arn = "ARN_LAMBDA_FUNCTION";
target.Id = "LAMBDA_FUNCTION_NAME";
target.Input = JsonSerializer.Serialize(new { someId, someDate});

var targetList = new List();
targetList.Add(target);

var putTargetRequest = new Amazon.EventBridge.Model.PutTargetsRequest()
{
  Rule = ruleName,
  Targets = targetList
};

await client.PutTargetsAsync(putTargetRequest);

The Lambda function is already created so I put the ARN and name on the Target. The idea is that there is one function but multiple rules will call it.

The rule, schedule, and target to the function are created when I run the code but the problem is that the function can't be triggered by the rule. When I edit the rule, update it in the AWS Console without changing anything the trigger works.

What am I missing?

user_8457704 · Answer

After searching through I found out I was missing the permission for Lambda.

//This line replaces the code above
var putRuleResponse = client.PutRuleAsync(putRuleRequest).Result;

var lp = new Amazon.Lambda.Model.AddPermissionRequest();
lp.FunctionName = FUNCTION_ARN;
lp.Action = "lambda:InvokeFunction";
lp.SourceArn = putRuleResponse.RuleArn;
lp.Principal = "events.amazonaws.com";
lp.StatementId = "SomeStatement";

var lambdaClient = new AmazonLambdaClient();
await lambdaClient.AddPermissionAsync(lp);

Amazon EventBridge rule cannot trigger a Lambda Function

1 Answers