aws_instance project

The project provides some simple tools for launching a quick EC2 instance without having to go to AWS console

It seems like I am often working on the CLI and need a quick EC2 instance fired up to test something. I can never remember the exact command sequence to launch an instance via AWS CLI. It also always feels like setting up terraform for a single short lived instance is too much work. So I usually have to break my flow, log into AWS console, create the instance, copy the public IP and get back to work. And since I'm easily distracted, I'll probably browse the web a while before I get back to work. :-\

This tool is designed to allow me to crank out a t2.micro ec2 linux instance in a flash, without leaving the cli.

This repo includes two versions of the tool.

• cli_instance.sh performs the operations using awscli and bash
• tf_instance.sh performs operations using terraform aws provider. ** This version is always going to be more robust

Note: could also create a Vagrant version I suppose...

Interesting trivia... I thought the terraform version would be much shorter in terms of lines of code.. Turns out it's not. The terraform version currently contains 149 lines, while the cli version contains 146 lines. But, the cli version was harder to write than the terraform version.. The cli version required 5476 characters vs 3255 for terraform. The cli required much longer, more complex lines of code, which are certainly more likely to contain bugs. So use terraform if you can. :-)

	$ cat tf_instance.sh terraform.tf | wc
			149     407    3255
	$ cat cli_instance.sh | wc
			146     562    5476

Subcommands:

• launch:

  • Creates an ssh-key in aws using the local ~/.ssh/id_rsa.pub
  • Launches a linux t2.micro instance of type ubuntu, aws or aws2
  • cli_instance.sh stores the instance ids launched in the instances.log file
  • Prints out connection instructions

• list:

  • list the deployed instances

• terminate:

  • Terminates all of the ec2 instances in instances.log (or terraform state)
  • deletes instances.log

Requirements

• Linux or mac workstation with bash, jq & openssh installed
• awscli. Required only for cli_instance.sh version. install with pip install awscli)
• terraform. Required only for the tf_instances.sh version. install instructions

Usage

	# Terraform version
	USAGE: ./tf_instance.sh launch|list|terminate [ubuntu|aws|aws2]

or

	# AWS CLI version
	USAGE: ./cli_instance.sh launch|list|terminate [ubuntu|aws|aws2]

Example usage

The following commands work the same for cli_instance.sh and tf_instance.sh

Launch an aws linux 2 instance in the current region (defined by AWS_DEFAULT_REGION env var)

	$ ./cli_instance.sh launch aws2
	Launching (1) aws2 instance size: t2.micro in us-east-1
	Looking up latest AMI for aws2... found: ami-009d6802948d06e52
	Using existing AWS key name: peterb154-asus-laptop
	Launching instance id: i-0c25a87f27b967980
	Connect with: ssh -i /home/peterb154/.ssh/id_rsa.pub ec2-user@54.81.198.132

List all launched instances and thier public IPs

	$ ./cli_instance.sh list
	i-0c25a87f27b967980 54.81.198.132

Terminate all launched instances

	$ ./cli_instance.sh terminate
	Terminating i-0c25a87f27b967980
	Removing instances log: ./instances.log

Launch an instance with a custom image (only works with Terraform)

	$ ./tf_instance.sh launch -var os="custom" -var custom_ami="alpine-ami-3.10.1" -var custom_user="alpine"