Do you regularly work with more than one EC2 instance for your dev and test work? EC2x lets you give each one a name you can remember and use these instead of AWS ids or public dns names.

For example, instead of dealing with ids like i-05bbd8ea9905f3aa5 or having to type :

ssh ec2-user\@ec2-52-38-22-116.us-west-2.compute.amazonaws.com

lets say you have instances named euler and gauss. You can now say :

ec2x ssh euler

or

ec2x stop gauss.

EC2x manages the mapping of the instance name to the public dns name so that you can use the same name for the instance across instance restarts. So you can start and stop your instances at will without having to update all your instance references in build scripts and configuration files.

You can also do :

ec2x remote euler <command>

to execute a shell command <command> on the remote instance named euler.

Also :

ec2x local <command>

to execute a local shell command <command> with the environment variables $euler and $gauss to the public dns names of the corresponding instances. This allows you to dynamically bind the dns name at run time and use the environment variable in config URLs etc that are used in the child processes.

The primary use case for ec2X is in dev and test environments where it is useful to be able restart instances on demand and still maintain stable local environments without using up a bunch of elastic IPs. Not recommended for production environments.

Using pip :

Check out this repository and then

    $ pip install -r requirements.txt .

The utilities in this library are intended to be used side by side with the AWS CLI, so we assume you have the CLI installed and have the necessary access to an AWS account where the EC2 instances are running. Please see the AWS CLI documentation for setup and usage. We will assume you are able to access your aws account using the CLI and have run aws configure to set up your keys and defaults, and can ssh into your instances using their public dns names.

We will also assume you have given your instance a user friendly name using the Name tag (provided as an argument to the run-instance CLI command or via the AWS admin console).

This package installs a command line script ec2x that supports the following commands. See ec2x <command> --help for further details.

ssh

ec2x ssh <instance_name> will ssh into the instance as ec2-user@<public-dns-name>`. If the instance is not running it will start it and ssh into it after it binds to the dns name of the started instance.

remote

ec2x remote <instance_name> command will execute the shell command on the remote instance after ssh as ec2-user@<public-dns-name>. If the instance is not running, it is started and the public dns name is bound dynamically before command execution.

local

ec2x local <command> executes the shell command in a sub-process that has an environment variable <instance_name>_id bound to the instance id and one name <instance_name> bound to the public dns name for each of the ec2 instances under the AWS account.

rehash

ec2x rehash writes a file named name_bindings to ~/.aws and you can use it to cache the bindings created by ec2x local and source it (from .bashrc etc.) so that you have them available in your current working shell.

If you set up an alias in your bash_profile file like so: alias ec2x_init='ec2x rehash && source ~/.ec2x/name_bindings' You can then simply run ec2x_init from your shell and this will set up your environment by updating against the current state of your EC2 instances.

This is an alpha release suitable only for development environments. Currently rehash will work only the bash shell. The local install should be stable, but the docker install is a work in progress. Several key workflows such as SSH dont really translate well to running inside a container at the moment. Tested mainly against my dev environment which has about 5 instances, not optimized for large installs. In general, Caveat Emptor.

Krishna Kumar

MIT License Copyright Krishna Kumar (2018)