AWS consuming data from API REST - amazon-web-services

I'm writing to you because I'm quite a novice with AWS... I only worked before with EC2 instances for simple tasks...
I am currently looking for an AWS service for reciving data using REST API calls (to external AWS services).
So far I have used EC2 where I deployed my library (python) that made calls and stored data in S3.
What more efficient ways does AWS offer for this? some SaaS?
I know that they are still more details to know in order to choose a good services but I would like to know from where I can start looking.
Many thanks in advance :)

I make API requests using AWS Lambda. Specifically, I leave code that makes requests, writes the response to a file and pushes the response object (file) to AWS S3.
You'll need a relative/absolute path to push the files to wherever you want to ingest. By default lambda servers current working directory is: /var/task but you may want to write your files to /tmp/ instead.
You can automate the ingestion process by setting a CloudWatch rule to trigger your function. Sometimes I chain lambda functions when I need to loop requests with changing parameters instead of packing all requests within a single function,
i.e.
I leave the base request (parameterized) in one function and expose the function through an API Gateway endpoint.
I create a second function to call the base function once for each value I need by using the Event object (which is the JSON body of a regular request). This data will replace parameters within the base function.
I automate the second function.
Tip:
Lambda sometimes will run your requests inside the same server. So if you're continuously running these for testing the server may have files from past calls that you don't want, so I usually have a clean-up step at the beginning of my functions that iterates through my filesystem to make sure there are no files before making the requests.
Using python 3.8 as a runtime I use the requests module to send the request, I write the file and use boto3 to push the response object to an aws S3 bucket.

To invoke an external service you need some "compute resources" to run your client. Under compute resources in aws we understand ec2, ecs (docker container) or lambda (serverless - my favorite)
You had your code already running on EC2 so you should already know you need VPC with a public subnet and ip address to make an outbound call regardless the compute resource you choose

Related

AWS Lambda - node app split into multiple lambda functions

Usually when I deploy my app to AWS Lambda it is still one self-contained app which resolves requests inside of it.
So no matter what request I send, full lambda starts and handles this request:
I know that some people take full advantage of lambdas and deploy each "endpoint" as individual lambda function like this:
How do you run this locally? To me it seems like you would have to run as many node apps as many endpoints you have.
Are there any frameworks/methods which help with such architecture?
Maybe something would be able to "extract" all endpoints from a node app and build lambdas for each of them?

How would I create a Minecraft EC2 server that automaticaly starts when someone tries to use it

Currently, I have a working modded Minecraft server working running on a C5 EC2 instance. The problem is that I have to manually start and stop the server which can be annoying for my friends. I was wondering if it would be possible to automate the EC2 state so that it runs as soon as a player attempts to join the sever. This would be similar to how Minecraft realms behaves which I heard Mojang was using AWS for:
https://aws.amazon.com/blogs/aws/hosting-minecraft-realms-on-aws/
I have looked up tutorials for this and this is the best I could come across:
https://github.com/trevor-laher/OnDemandMinecraft
The problem with this solution is that it requires to make a separate website to log users in and start the EC2 instance while I want the startup and shutdown to be completely automatic.
I would appreciate any guidance.
If the server is off, it would not be possible to "connect" to the server. Therefore, another mechanism is required that can be used to start the server.
Combine that with your desire to minimise costs and the only real solution is to somehow trigger an AWS Lambda function, which could start the server.
There are a few ways you could have users trigger the AWS Lambda function:
Make a call to API Gateway
Upload an object to Amazon S3
Somehow put a message in an SNS topic or an SQS queue
Trigger an Amazon CloudWatch Alarm (which calls Lambda via SNS)
...and probably other ways
When considering a method to use, you should consider security implications such as:
Whether only authorized users should be able to trigger the Lambda function, or is it okay that anybody (eg a web crawler) might trigger it.
Whether you willing to give your friends AWS credentials (not a good idea) that they could use to start the server directly, or whether it should be an indirect method.
Frankly, I would recommend the following architecture:
Create an AWS Lambda function that turns on the server
Create an API Gateway that triggers the Lambda function
Give a URL to your friends that calls the API Gateway and passes a 'secret' (effectively a password)
The API Gateway will call the Lambda function, passing the secret
The Lambda function confirms that the secret is correct and starts the Amazon EC2 instance with Minecraft installed
Here is a tutorial that shows many of these concepts: Build an API Gateway API with Lambda Integration
The purpose of the secret is to avoid the server from starting if an unauthorized person (or a bot) happens to hit the API Gateway endpoint. They will not provide the secret, so the server will not be started.
Stopping the server after a period of non-use is a different matter. The library you referenced might be able to assist with finding a way to do this. You could have a script running on the Minecraft server that monitors the game and, after a period of inactivity, simply calls the operating system to perform a Shutdown.
You could use a BungeeCord hub server that then allows user to begin a connection to the main server and spin it up via. AWS.
This would require the bungee server to be always up however, but the cost of hosting a small bungee server should be relatively cheap.
I don't think there's any way you could do this without having a small server that receives the initial request to spin up the AWS machine.

AWS application consistent snapshots of EC2 instances

I'm currently setting up a small Lambda to take snapshots of all the important volumes of our EC2 instances. To guarantee application consistency I need to trigger actions inside the instances: One to quiesce the application before the snapshot and one to wake it up again after the snapshot is done. So far I have no clue how to do this.
I've thought about using SNS or SQS to notify the instances about start and stop of the snapshot, but that has several problems:
I'll need to install (and develop) a custom listener inside the instances.
I'll not get feedback if the quiescing/wake-up is done.
So here's my question: How can I trigger an action inside an instance from an Lambda?
But maybe I'm approaching this from the wrong direction. Is there really no simple backup solution? I know azure has a snapshot based backup service that can do application consitent backups. Did I just miss an equivalent AWS service?
Edit 1:
Ok, it looks like the feature 'Run Command' of AWS Systems Manager is what I really need. It allows me to run scripts, Ansible playbooks and more inside an EC2 instance. When I've got a working solution I'll post the necessary steps.
You can trigger a Lambda function on demand:
Using AWS Lambda with Amazon API Gateway (On-Demand Over HTTPS)
You can invoke AWS Lambda functions over HTTPS. You can do this by
defining a custom REST API and endpoint using Amazon API Gateway, and
then mapping individual methods, such as GET and PUT, to specific
Lambda functions. Alternatively, you could add a special method named
ANY to map all supported methods (GET, POST, PATCH, DELETE) to your
Lambda function. When you send an HTTPS request to the API endpoint,
the Amazon API Gateway service invokes the corresponding Lambda
function. For more information about the ANY method, see Step 3:
Create a Simple Microservice using Lambda and API Gateway.

AWS Lambda - Work with services outside Amazon services?

After reading about AWS Lambda I've taken a quite interest in it. Although there is one thing that I couldn't really find any info on. So my question is, is it possible to have lambda work outside Amazon services? Say if I have a database from some other provider, would it be possible to perform operations on it through AWS Lambda?
Yes.
AWS Lambda functions run code just like any other application. So, you can write a Lambda function that calls any service on the Internet, just like any computer. Of course, you'd need access to the external service across the Internet and access permissions.
There are some limitations to Lambda functions, such as functions only running for a maximum of five minutes and only 500MB of local disk space.
So when should you use Lambda? Typically, it's when you wish some code to execute in response to some event, such as a file being uploaded to Amazon S3, data being received via Amazon Kinesis, or a skill being activated on an Alexa device. If this fits your use-case, go for it!

Is amazon lambda suitable for web scraping?

If I create a function to get webpages. Will it execute it on different IP per execution so that my scraping requests dont get blocked?
I would use this AWS pipeline:
Where at source on the left you will have an EC2 instance with JAUNT which then feeds the URLS or HTML pages into a Kinesis Stream. The Lambda will do your HTML parsing and via Firehose stuff everything into S3 or Redshift.
The JAUNT can run via a standard WebProxy service with a rotating IP.
Yes, lambda by default executes with random IPs. You can trigger it using things like event bridge so you can have a schedule to execute the script every hour or similar. Others can possibly recommend using API Gateway, however, it is highly insecure to expose API endpoints available for anyone to trigger. So you have to write additional logic to protect it either by hard coded headers or say oauth.
AWS Lambda doesn't have a fixed IP source as mentioned here
however, I guess this will happen when it gets cooled down, not during the same invocation.
Your internal private IP address isn't what is seen by the web server, it's the public ip address from AWS. As long as you are setting the headers and signaling to the webserver that your application is a bot. See this link for some best practices on creating a web scrapper:
https://www.blog.datahut.co/post/web-scraping-best-practices-tips
Just be respectful of how much data you pull and how often is the main thing in my opinion.
Lambda is triggered when a file is placed in S3, or data is being added to Kinesis or DynamoDB. That is often backwards of what a web scraper needs, though certainly things like S3 could perform as a queue/job runner.
Scraping on different IPs? Certainly lambda is deployed on many machines, though that doesn't actually help you, since you can't control the machines or their IP.