The provided execution role does not have permissions to call createnetworkinterface on ec2

Question

Problem :

I am new to Lambda and want to setup my Lambda to access my Mongo server on one of the EC2 instances in VPC. I tried selecting all the subnets and security groups, but still I am getting the following error while trying to save "You are not authorized to perform: CreateNetworkInterface."

I think, I need to do some kind of policy setup in AWS IAM to make this happen.

I have required "AdministratorAccess" and I am trying very hard to add IAM role to my account.

Please let me know what policy/role I need to add for this problem to be fixed?

Answer 1

I had faced this issue in the recent past. I did lot of research on it.

I found the following solution to solve your issue.

If the error message is saying that "This Lambda function is not authorized to perform: CreateNetworkInterface" then it is more practical that Lambda role needs to be modified with appropriate policy. So fixed the problem by adding the lambda with the policy actions as follows:

NetworkLambdaRole:

 Type: "AWS::IAM::Role"

 Properties:

   RoleName: "Network-Lambda-Role"

   AssumeRolePolicyDocument:

     Version: '2012-10-17'

     Statement:

     -

       Effect: "Allow"

       Principal:

         Service:

         - "lambda.amazonaws.com"

       Action:

       - "sts:AssumeRole"

   Policies:

   - PolicyName: "network-lambda-role-policy"

     PolicyDocument:

       Version: '2012-10-17'

       Statement:

       - Effect: "Allow"

         Action: [

           "ec2:DescribeInstances",

           "ec2:CreateNetworkInterface",

           "ec2:AttachNetworkInterface",

           "ec2:DescribeNetworkInterfaces",

           "ec2:DeleteNetworkInterface"

         ]

         Resource: "*"