I have a Django web application, running on AWS Elastic Beanstalk, inside of an EC2 linux instance.
Only the load balancer is accessible to the internet, for security reasons. Deployment to the EC2 app server is facilitated by Elastic Beanstalk, but new packages added to the repository can't be installed without an internet connection.
What is the standard way to automatically update without an internet connection?
Should I just create another EC2 and use it as a proxy server? How can I configure this?
Are there any references on this topic?
Typically NAT gateway is used for that:
You can use a network address translation (NAT) gateway to enable instances in a private subnet to connect to the internet or other AWS services, but prevent the internet from initiating a connection with those instances.
There are also NAT instances which also can be used for the same purpose. However NAT gateway is a managed and scalable service and is usually preferred over NAT instances.
Related
I am having an Amazon RDS Postgres instance which resides in the default VPC.
To connect to it, i am using different EC2 instances (Java Spring Boot and NodeJs) running in ElasticBeanstalk. These instances also reside in the default VPC.
Do these EC2 instances connect to/query the RDS instance through the internet or the calls do not leave the AWS Network?
If they leave the AWS network and the calls go through the internet, is creating a VPC endpoint the right solution? Or my whole understanding is incorrect.
Thanks a lot for your help.
Do these EC2 instances connect to/query the RDS instance through the internet or the calls do not leave the AWS Network?
The DNS of the RDS endpoint will resolve to private IP address when used from within VPC. So communication is private, even if you use public subnets or set your RDS instance as publicly available. However, for connection from outside of AWS, the RDS endpoint will resolve to public IP address if the db instance is publicly available.
If they leave the AWS network and the calls go through the internet, is creating a VPC endpoint the right solution?
There is no VPC endpoint for RDS client connections, only for management actions (creating db-instance, termination, etc). In contrast, Aurora Serverless has Data API with corresponding VPC endpoint.
To secure your DB-Instances communications you need to be sure at least about the following:
locate your RD in private subnet (route table does not contain default outbound route to internet gateway).
RDS security group just accept traffic inbound only from instances security group/groups on TCP port for PostgreSQL which is usually 5432.
In this case Traffice to RDS will go localy in your vpc, for vpc endpoints it can be used to access RDS API operations privatly which is not your case (you just need to connect your app to DB using connection string)
I'm trying to make beanstalk instances not connect outside the VPC to public internet.
The problem is that, when I clear the outbound security group and actually block the internet access, it makes the instances not start properly and throw error "502 Bad Gateway", also the health status in beanstalk change to "unknown".
When I checked the system log I saw that the instance is trying to connect outside the VPC in the user data script.
How can I solve this problem?
Using EB environment in a private subnet (no internet) is not that straight forward. The general consideration of how to do this are described in the AWS docs:
Using Elastic Beanstalk with Amazon VPC
For example, EB uses Network Time Protocol (NTP) thus you have to have internet connectivity. Without that, as docs describe, there are issues with Elastic Beanstalk health reporting.
You also need to setup VPC endpoints for Elastic Beanstalk as well as the endpoints for other services (e.g. S3):
Using Elastic Beanstalk with VPC endpoints
If you .ebextenstions install any packages from the internet, you need to ensure that you have properly setup NAT gateway or NAT instance.
The docs also provide example in CloudFormation vpc-private.yaml with exemplary setup for Internet gateway, NAT gateway, and route table.
I will be using the PythonAnywhere PaaS service. It is using AWS on us-east-1 for all its EC2 instances.
They don't offer Redis and I plan to create a regular AWS Redis instance using Elasticache.
Ideally I would like to connect to the Redis instance from the paas using local internal network of AWS.
Do you know if this kind of setup is possible? That is benefit from local network between paas AWS hosted to regular EC2 instances?
(The paas allows external connections.)
Multiple AWS VPCs can connect to each other via VPC Peering. The VPCs must be in the same region and have non-overlapping IP addresses.
However, this requires changes within both VPCs to connect to each other. It is unlikely that PythonAnywhere would want to modify their configuration for you. (But, by all means, ask them!)
An alternative is to connect to your Redis cluster within your own VPC, but do it via a Public IP address. The traffic will travel between VPCs across the 'edge' of the Internet -- that is, it won't go on the Internet proper, it will just transit within AWS' network if it is in the same Region. So, it is using the "local internal network of AWS", but via a Public IP address.
I have a tomcat app deployed onto multiple ec2 instances behind ELB ... Is there any way to access each instance using jmx? AWS provides any service for it??
Thanks.
Is there any way to access each instance using jmx?
If each instance has a public IP or Elastic IP, and the appropriate port in the Security Group is open, then you could connect directly, bypassing the ELB. You'll have to go around the ELB somehow in order to connect via JMX. I suggest using a bastion host and SSH forwarding.
AWS provides any service for it??
AWS does not provide any service specifically for this. This is just general networking, which is provided by the VPC service.
I have Application deployed on Elastic Beanstalk and it need to make call to an external API Server which can reply to only single IP. AutoScaling is in picture. So I need to Route all my OUTBOND traffic through a Single Server. So that External API thinks that Request is coming from a single IP.
May be by using NAT or any Proxy Server or VPN.
Yes, you can use a NAT server to direct all traffic via one host.
The instructions to setup a NAT server are here.
Basically you launch a special AMI, setup routing and you're done.
Going this way, it's advisable to push your elastic beanstalk servers into a VPC. This way you'll gain some more security out of this move.