my web servers needs to access S3. When I place them in the public subnets, or place them in the private subnets and use NAT gateways, everything works fine:
IAmazonS3 client = new AmazonS3Client("myaccesskey", "mysecretkey", enRegion);
PutObjectRequest putReq = new PutObjectRequest();
putReq.FilePath = "c:\temp\myphoto.jpg";
putReq.BucketName = "MyBucket";
putReq.Key = "myphoto.jpg";
PutObjectResponse putResp = client.PutObject(putReq);
Now I tried to place the web servers in the private subnet with S3 endpoints, my code can no longer access S3. Do I need to change the code?
Just a FYI VPC's are truly private. Only traffic that you explicitly allow can transit the borders of the VPC.
So, inside a VPC, instances needing access to external resources either need to be assigned an EIP (in which case they can access external resources using AWS's infrastructure), or you need to provide a NAT host (in which case all of the traffic egresses the VPC via your own NAT).
As of May 11th, 2015, AWS has released a "VPC Endpoint" for S3, which allows access to S3 directly from a VPC without having to go through a proxy host or NAT instance
You Can Create Endpoint, choose the desired VPC, and customize the access policy (if you want):
Please Refer AWS Blog Post For Details.
Hope this helps.
Related
I have the following AWS VPC configuration:
2 public subnets
2 private subnets
Cloudfront is in front of the load balancer. The load balancer is linked to the public subnets and my RDS database reside in the private subnets.
What i want to accomplish is:
Create an API Gateway (publicly accessible) but restricted to only a specific IP address that can access it. The API Gateway is connected to a lambda function that, when called/triggered, the function must update some table data of my (private) RDS Postgres instance.
From my understanding the first step would be to create an IAM role for the lambda function to be only accessible by the IP address mentioned above.
Now what is the best way to access a private RDS from that lambda connected to API Gateway? Especially without using Nat Gateway because of the crazy cost associated to it.
Can someone help me just figure out how to do it, i am referring to the high level understanding how to do it?
As Norman said in their comment, you can control access to your API in API Gateway, and limit it to certain IP addresses, with API Gateway Resource Policies. This will at the same time control access to your Lambda that's behind that API.
You can then edit the Lambdas Configuration -> VPC setting and add it to a subnet that has access to your RDS database (and put it either in the same subnet as the database, or another subnet that has access permissions to the RDS subnet). To connect your Lambda to a VPC, the Lambda execution role will need the following permissions
ec2:CreateNetworkInterface
ec2:DescribeNetworkInterfaces
ec2:DeleteNetworkInterface
They are for example included in the managed policy AWSLambdaVPCAccessExecutionRole. Here you can read more about configuring a Lambda for VPC access.
I have a docker image which is just an Java application. The java application reads data from DynamoDB and S3 buckets and outputs something (its a test app). I have hosted the docker images onto public docker-hub repo.
In AWS, i have created private subnet which is hosting an EC2 via AWS ECS. Now to have security high; i am using VPC Endpoints for DynamoDB and S3 bucket operations for the containers.
And i have used NAT Gateway to allow EC2 to pull docker images from docker-hub.
Problem:
When i remove VPC Endpoint, the application is able to read DynamoDB and S3 via NAT. Which means the traffic is going through public network.
Thoughts:
Can not whitelist the Ip addresses of Dockerhub as it can change.
Since AWS ECS handles all the docker pull etc tasks, i do not have control to customize.
I do not want to use AWS container registry. I prefer dockerhub.
DynamoDB/S3 private addresses are not known
Question:
How to make sure that traffic for docker hub should only be allowed via NAT?
How to make sure that the DynamoDB and S3 access should be via Endpoints only?
Thanks for your help
IF you want to restrict outbound traffic over your NAT (by DNS hostname) to DockerHub only you will need a third party solution that can allow or deny outbound traffic before it traverses the internet.
You would install this appliance in a separate subnet which has NAT Gateway access. Then in your existing subnet(s) for ECS you would update the route table to have the 0.0.0.0/0 route speak to this appliance (by specifying its ENI). If you check the AWS marketplace there may be a solution already in place to fulfil the domain filter.
Alternatively you could automate a tool that is able scrape the whitelisted IP addresses for DockerHub, and then have it add these as allow all traffic rules with a NACL. This NACL would only be applied to the subnets that the NAT Gateway resides in.
Regarding your second question, from the VPC point of view by adding the prefix list of the S3 and DynamoDB endpoints to the route table it will forward any requests that hit these API endpoints through the private route.
At this time DynamoDB does not have the ability to prevent public routed interaction, however S3 does. By adding a condition of the VPCE to its bucket policy you can deny any access that tries to interact outside of the listed VPC Endpoint. Be careful not to block yourself access from the console however, by blocking only the specific verbs that you don't want allowed.
There is a static website on AWS S3 bucket.
This site has to be available only for one team. It could be authentication system, or access via AWS Client VPN Endpoint (only this team uses AWS VPN).
I have read about S3 Access Points, VPC Endpoints, Bucket Policy with VPC and IP-restriction, made some experiments. There was an idea to restrict access only for VPC with VPN. But I can not forward bucket traffic to VPN tunnel, because my bucket IP address changes all the time.
And this way doesn't look straight.
What service or service combination can I use to implement restriction with minimum efforts?
One approach I have done in the past is using an API Gateway as a proxy to static UI content hosted in a private S3 bucket. You can either use a public or private APIGW. With public you will need an APIGW resource policy to restrict access to the VPC-endpoint. You can also use a private APIGW-- the only downside is AWS doesn't support custom DNS for private api gateways (you will be accessing your site using a url similar to https://{rest-api-id}-{vpce-id}.execute-api.{region}.amazonaws.com/{stage}-- documentation). AWS also offers good documentation on creating an apigw as an s3 proxy.
In this example the flow of traffic would go: client-> vpn -> vpc endpoint -> apigw -> s3
Hopefully this helps!
My setup is:
S3 (website) -> API Gateway -> Lambda -> RDS
-> S3 (configuration)
-> Shopify
-> Transactional Mail
I have an Internet Gateway set up to allow access to my S3 configurations and I need to hook up a NAT to allow me to make my calls out to 3rd parties. I've attempted to only use the NAT (per this question) by changing my Routing Table entry for 0.0.0.0/0 -> {my NAT}, but that just results in not being able to access my S3 configuration bucket.
Any help would be greatly appreciated!
Edit: To be clear I've read the documentation, what I'm having issues understanding is the relationships between the Security Group my Lambdas and RDS share, and the Subnets they're associated with.
When I configure my lambda to be part of the security group my RDS instances is in, I need to associate it with at least 2 subnets... Should those be new subnets, and not the ones associated with my RDS instances? AKA does a lambda need to share a subnet with an RDS in order to access it?
If the Lambda function only needs to access VPC resources and S3, then the easiest way to configure this is to add an S3 Endpoint to your VPC. If your Lambda function needs to access VPC resources plus other resources besides S3 and DynamoDB (the only 2 services that currently support VPC endpoints) then your Lambda function has to be in a private subnet with a NAT Gateway.
Instances in a public subnet have the option of having a public IP address, but it isn't a requirement. Lambda functions in a VPC do not ever get public IP addresses, which is why Lambda functions inside a VPC have to be in a private subnet with NAT gateway in order to have Internet access.
The only time Lambda functions get a public IP is when they are not in a VPC at all. In that instance they can access anything except resources in your VPC.
A note about your "same security group" comment: Being in the same security group does not allow resources to access each other. The Lambda function needs to be in a security group that the RDS security group has granted access to. Regarding subnets, the Lambda simply needs to be in any subnet in the same VPC, it does not need to be in the same subnet as the RDS instance.
I am planning to use AWS File Gateway in a hybrid environment where I will mount the File Gateway to an EC2 instance from within a private subnet. As per AWS documentation, all data transfer is done through HTTPS when using File Gateway.
But since my File Gateway, EC2 instance and S3 are all inside the AWS environment, will my File Gateway still transfer files over the internet to S3 service endpoint (s3.amazonaws.com) or will it leverage VPC endpoint for S3?
Note: I cannot use EFS for this purpose as it's not HIPAA complaint.
A VPC Endpoint for S3 uses a predefined IP prefix list in your subnet route tables, which hijacks all of the traffic bound for all of the IP addresses assigned to S3 in your region... so from a subnet associated with an S3 VPC endpoint, all traffic bound for any S3 address in the region is routed through the endpoint.
To state it another way, when correctly configured, an S3 VPC endpoint becomes the only way S3 can be accessed from the associated subnets, and because it's done at the IP routing layer, anything accessing S3 from those subnets will automatically and transparently use the endpoint.
The prefix list ID logically represents the range of public IP addresses used by the service. All instances in subnets associated with the specified route tables automatically use the endpoint to access the service; subnets that are not associated with the specified route tables do not use the endpoint.
http://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/vpc-endpoints.html
In theory, if you configure your VPC Route Table to use the VPC Endpoint, then any traffic destined for S3 will be sent via the VPC Endpoint. (By the way, it might only work when connecting to S3 in the same region.)
Regardless, even if the traffic is routed through your Internet Gateway to the Amazon S3 endpoint, the traffic will not traverse the real "Internet" -- it will simply pass through the AWS edge of the Internet, never leaving the AWS data center (as long as it is in the same Region).