AWS Lambda can't reach resources created from MobileHub

Question

I am having an issue accessing resources created in MobileHub from Lambda and that does not make sense for me at all.. I have two questions (maybe it is the same question..):

1. Why lambda can't access all resources created by MobileHub when it has fullAccess permissions to those specific resources? I mean, if I create those resources separately I can access them but not created ones from MobileHub..

2. Is there a way to grant access to these resources or am I missing something?

Update

The issue was VPC . Basically when I enabled VPC on lambdas to reach rds which have no public access I couldn't reach any other resources, when I disabled it - RDS was unreachable. The question is how to combine vpc with role policies?

Answer 1

You can find the resources associated with your project using the left-side navigation in the Mobile Hub console and select "Resources." If you want to enable your AWS Lambda functions to be able to make use of any AWS resources, then you'll need to add an appropriate IAM Policy to the Lambda Execute IAM Role. You can find this role in your project on the "Resources" page under "AWS Identity and Access Management Roles." It is the role that has "lambdaexecutionrole" in the name. Select this role then attach whatever policies you like in the IAM (Identity and Access Management) console.

For more information on how to attach roles to polices, see:
http://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_manage_modify.html

And, if you have further problems, you can get help from the AWS community in the forums, here:
https://forums.aws.amazon.com/forum.jspa?forumID=88

**Update - WRT VPC Question**
This question should really go to an expert on the AWS Lambda team. You can reach them in the AWS Forums (link above). However, I'll take a shot at answering (AWS Lambda experts feel free to chime in if I'm wrong here). When you set the VPC on the Lambda function, I expect that any network traffic coming from your Lambda function will have the same routing and domain name resolution behavior as anything else in your VPC. So, if your VPC has firewall rules which prevent traffic from the VPC to, for example, DynamoDB, then you won't be able to reach it. If that is the case, then you would need to update those rules in your VPC's security group(s) to open up out-going traffic. Here's a blurb from a relevant document.

From https://aws.amazon.com/vpc/details/:
*AWS resources such as Elastic Load Balancing, Amazon ElastiCache, Amazon RDS, and Amazon Redshift are provisioned with IP addresses within your VPC. Other AWS resources such as Amazon S3 and Amazon DynamoDB are accessible via your VPC's Internet Gateway, NAT gateways, VPC Endpoints, or Virtual Private Gateway.*

This doc seems to explain how to configure the gateway approach:
http://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/vpc-endpoints.html