How to run a code in an Amazone's EC2 instance? - python

I understand nearly nothing to the functioning of EC2. I created an Amazon Web Service (AWS) account. Then I launched an EC2 instance.
And now I would like to execute a Python code in this instance, and I don't know how to proceed. Is it necessary to load the code somewhere in the instance? Or in Amazon's S3 and to link it to the instance?
Where is there a guide that explain the usages of instance that are possible? I feel like a man before a flying saucer's dashboard without user's guide.

Here's a very simple procedure to move your Python script from local to EC2 Instance and run it.
> 1. scp -i <filepath to Pem> <filepath to Py File> ec2-user#<Public DNS>.compute-1.amazonaws.com:<filepath in EC2 instance where you want
> your file to be>
> 2. Cd to to the directory in EC2 containing the file. Type Python <Filename.py> There it executed.
Here's a concrete examples for those who likes things shown step-by-step:
In your local directory, create a python script with the following code: print("Hello AWS")
Assuming you already have AWS already set up and you want to run this script in EC2, you need to SCP (Secure Copy Protocol) your file to a directory in EC2. So here's an example:
- My filepath to pem is ~/Desktop/random.pem.
- My filepath to py file is ~/Desktop/hello_aws.py
- My public DNS is ec22-34-12-888
- The ec2 directory where I want my script to be is in /home/ec2-user
- So the full command I run in my local terminal is:
scp -i ~/Desktop/random.pem ~/Desktop/hello_aws.py ec2-user#ec2-34-201-49-170.compute-1.amazonaws.com:/home/ec2-user
Now ssh to your ec2 instance, cd to /home/ec2-user (Or wherever you put your file) and Python hello_aws.py

You have a variety of options. You can browse through a large library of AMIs here.
You can import a vm, instructions are here.
This is a general article about AWS and python.
And in this article, the author takes you through a more advanced system with a combination of datastores in python using the highly recommend django framework.

Launch your instance through Amazon's Management Console -> Instance Actions -> Connect
(More details in the getting started guide)
Launch the Java based SSH CLient
Plugins-> SCFTP File Transfer
Upload your files
run your files in the background (with '&' at the end or use nohup)
Be sure to select an AMI with python included, you can check by typing 'python' in the shell.
If your app require any unorthodox packages you'll have to install them.

Running scripts on Linux ec2 instances
I had to run a script on Amazon ec2 and learned how to do it. Even though the question was asked years back, I thought I would share how easy it is today.
Setting up EC2 and ssh-ing to ec2 host
Sign up and launch an ec2 instance(Do not forget to save the certificate file that will be generated while launching ec2) with default settings.
Once the ec2 is up and running, provide required permissions to the certificate file chmod 400 /path/my-key-pair.pem (or .cer file)
Run the command: ssh -i /path/my-key-pair.pem(.cer) USER#Public DNS(USER data changes based on the operating system you have launched, refer to the below paragraph for more details && Public DNS can be obtained on ec2 instance page)
Use the ssh command to connect to the instance. You specify the private key (.pem) file and user_name#public_dns_name. For Amazon Linux, the user name is ec2-user. For RHEL, the user name is ec2-user or root. For Ubuntu, the user name is ubuntu or root. For Centos, the user name is centos. For Fedora, the user name is ec2-user. For SUSE, the user name is ec2-user or root. Otherwise, if ec2-user and root don't work, check with your AMI provider.
Clone the script to EC2
In order to run the scripts on ec2, I would prefer storing the code on Github as a repo or as a gist(if you need to keep code private) and clone into ec2.
Above mention is very easy and is not error-prone.
Running the python script
I have worked with RHEL Linux instance and python was already installed. So, I could run python script after ssh-ing to host directly. It depends on your operating system you choose. Refer to aws manuals if it's not installed already.
Reference: AWS Doc

Related

How to Host a Flask website from localhost 5000

Hello I coded this website that generates math problems (Here is the code: Here)
It is coded on flask and it is locally being hosted on this link that is not accessible to other people http://127.0.0.1:5000/ .I have a google domain and I want to have a website. What things / services do I need to use. I have been wait to see if I need to use AWS but I think I might need to. I have tried things like transferring it off of flask but I can't. If this is a repost sorry please post there answer thanks -Ben
I am assuming what you're asking is to host your flask web site so others can view it. The address you mention in your post is the local host address for your computer and is only accessible from your own computer. If you only want someone on your same network (WiFi) to access it, you would need to replace "127.0.0.1" with the IP address of your computer. You would also likely have to open up a firewall on your computer to allow the port 5000.
However, if you want anyone on the internet to access your site, there are a ton of ways to do this but since you mentioned AWS, you can do this easily by running a small EC2 instance (virtual server). If you have a new AWS account and have not already run any EC2 in that account, you can actually run a small EC2 instance for free for a whole year. Great for small projects. If you're just getting started with EC2, you may want to go here https://aws.amazon.com/ec2/getting-started/
Basic steps:
Spin up an EC2 instance. Choose the default Amazon Linxu 2 OS type, make sure to create/assign a key pair so you can later ssh into it, make sure the Allow SSH from anywhere setting is checked/selected and the Allow HTTP checkbox is checked (not HTTPS).
Wait for the instance to launch.
Log into your instance by clicking on your ec2 instance in the list of ec2 instnaces and click the Connect button, click the Connect button again (Instance connect tab). If that doesn't work, follow the steps on the SSH client tab.
Install flask
pip3 install flask
Clone your git repo
git clone https://github.com/some0ne14/Math-Ibex.git
Change to your repos' folder
cd Math-Ibex/Math-Practice-Website-master
Edit your main.py so that the app.run line looks like the following (you can do this on GitHub before you run git clone actually or use the nano command to edit the file easily). This allows the system to run on the standard web port 80.
app.run(host='0.0.0.0', port=80, debug=True)
Run the following to start the application. If you want to run it as a service so you can walk away or close the terminal and it will still stay running, just search on here how to run flask as a service.
python3 main.py
You can now connect to your server with any web browser using your EC2 instance's public IP address or generated AWS DNS name (available on the EC2 instnace property page).
Make sure to stop your instance when not using it to save those free runtime minutes.

Run commands remotely on a GCP machine

I want to run commands remotely from a GCP instance to another one, using a Python script on a Debian machine.
I know that the gcloud ssh command can do that with the subprocess module, but I don't know how to proceed faster as it creates a new key each time I run the command. Is there a way to operate with a service account for example, on which I could setup permissions and keys for each machine on my GCP project?
Create a SSH Key in your "source" machine
ssh-keygen
And then add your public key into the ssh keys tab on the metadata page on Google Cloud Console, under the settings category, from the Compute Engine section.
Then, you should be able to log in to the other instance doing
ssh [user#]other_instance_ip [optional command to execute]

How to Deploy Flask app on AWS EC2 Linux/UNIX instance

How to deploy Flask app on AWS Linux/UNIX EC2 instance.
With any way either
1> using Gunicorn
2> using Apache server
It's absolutely possible, but it's not the quickest process! You'll probably want to use Docker to containerize your flask app before you deploy it as well, so it boils down to these steps:
Install Docker (if you don't have it) and build an image for your application and make sure you can start the container locally and the app works as intended. You'll also need to write a Dockerfile that sets your runtime, copies all your directories and exposes port 80 (this will be handy for AWS later).
The command to build an image is docker build -t your-app-name .
Once you're ready to deploy the container, head over to AWS and launch an EC2 instance with the Linux 2 machine. You'll be required to create a security key (.pem file) and move it to somewhere on your computer. This acts like your credential to login to your instance. This is where things get different depending on what OS you use. On Mac, you need to cd into your directory where the key is and modify the permissions of it by running chmod 400 key-file-name.pem. On Windows, you have to go into the security settings and make sure only your account (ideally the owner of the computer) can use this file, basically setting it to private. At this point, you can connect to your instance from your command prompt with the command AWS gives you when you click connect to instance on the EC2 dashboard.
Once you're logged in, you can configure your instance to install docker and let you use it by running the following:
sudo amazon-linux-extras install docker
sudo yum install docker
sudo service docker start
sudo usermod -a -G docker ec2-user
Great, now you need to copy all your files from your local directory to your instance using SCP (secure transfer protocol). The long way is to use this command for each file: scp -i /path/my-key-pair.pem file-to-copy ec2-user#public-dns-name:/home/ec2-user. Another route is to install FileZilla or WinSCP to speed up this process.
Now that all your files are in the instance, build the docker container using the same command from the first step and activate it. If you go to the URL that AWS gives you, your app should be running on AWS!
Here's a reference I used when I did this for the first time, it might be helpful for you to look at too

Running Python Script in an existing EC2 instance on AWS

I have an API (in python) which has to alter files inside an EC2 instance that is already running. I'm searching on boto3 documentation, but could only find functions to start new EC2 instances, not to connect to an already existing one.
I am currently thinking of replicating the APIs functions to alter the files in a script inside the EC2 instance, and having the API simply start that script on the EC2 instance by accessing it using some sort of SSH library.
Would that be the correct approach, or is there some boto3 function (or in some of the other Amazon/AWS libraries) that allows me to start a script inside existing instances?
An Amazon EC2 instance is just like any computer on the Internet. It is running an operating system (eg Linux or Windows), and it has standard security in-built. The fact that it is an Amazon EC2 instance has no impact.
So, the question really becomes: How do I run a command on a remote computer?
Typical ways of doing this include:
Connecting to the computer (eg via SSH) and running a command
Running a service on the computer that listens on a particular port (eg responding to an API request)
Using remote shell commands to run an operation on another computer
Fortunately, AWS offers an additional option: Use the AWS Systems Manager Run Command:
AWS Systems Manager Run Command lets you remotely and securely manage the configuration of your managed instances. A managed instance is any Amazon EC2 instance or on-premises machine in your hybrid environment that has been configured for Systems Manager. Run Command enables you to automate common administrative tasks and perform ad hoc configuration changes at scale. You can use Run Command from the AWS console, the AWS Command Line Interface, AWS Tools for Windows PowerShell, or the AWS SDKs. Run Command is offered at no additional cost.
Administrators use Run Command to perform the following types of tasks on their managed instances: install or bootstrap applications, build a deployment pipeline, capture log files when an instance is terminated from an Auto Scaling group, and join instances to a Windows domain, to name a few.
Basically, it is an agent installed on the instance (or, for that matter, on any computer on the Internet) and commands can be sent to the computer that are executed by the agent. In fact, the same command can be sent to hundreds of computers if desired.
The AWS Systems Manager Run Command can be triggered by an API call, such as a program using boto3.
Unless you have a specific service running on that machine which allows you to modify mentioned files. I would make an attempt to log onto EC2 instance as to any other machine via network.
You can access EC2 machine via ssh with use of paramiko or pexpect libraries.
If you want to use the execute a script inside of an existing EC2 instance - you could use the reference from the existing answer here : Boto Execute shell command on ec2 instance
IMO, to be able to start a script inside the EC2, the script should be present on the EC2.

Controlling VMs using Python scripts

I want to manage virtual machines (any flavor) using Python scripts. Example, create VM, start, stop and be able to access my guest OS's resources.
My host machine runs Windows. I have VirtualBox installed. Guest OS: Kali Linux.
I just came across a software called libvirt. Do any of you think this would help me ?
Any insights on how to do this? Thanks for your help.
For aws use boto.
For GCE use Google API Python Client Library
For OpenStack use the python-openstackclient and import its methods directly.
For VMWare, google it.
For Opsware, abandon all hope as their API is undocumented and has like 12 years of accumulated abandoned methods to dig through and an equally insane datamodel back ending it.
For direct libvirt control there are python bindings for libvirt. They work very well and closely mimic the c libraries.
I could go on.
follow the directions here to install docker https://docs.docker.com/windows/ (it includes Oracle VirtualBox (if you dont already have it)
#grab the immage
docker pull kalilinux/kali-linux-docker
#run a specific command
docker run kalilinux/kali-linux-docker <some_command>
#open interactive terminal to "docker image"
docker run -t -i kalilinux/kali-linux-docker /bin/bash
if you want to mount a local volume you can use the `-v dst src` switch in your run command
#mount local ./training/webapp directory into kali image # /webapp
docker run kalilinux/kali-linux-docker -v /webapp training/webapp <some_command>
note that these are run from the regular windows prompt to use python you would need to wrap them in subprocess calls ...

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