Sty

Overview

Sty is a set of handy command line tools meant to help with day-to-day work with AWS. Sty is working on Mac and Linux using Bash or Zsh.

The main use case for Sty is to obtain and store temporary AWS credentials for MFA enabled AWS users who are required to assume a role in the different account.

Sty can also help to access EC2 instances using SSH or SSM Session. It provides a convenient command line interface to quickly select a server and initiate a connection.

Installation

Sty is written in Ruby so you need to ensure it installed beforehand. Most modern Linux and Mac versions should have Ruby pre-installed. In any case, it is recommended to use Ruby version manager such as rbenv

To install Sty run:

gem install sty

During installation, Sty creates its executable /usr/local/bin/sty. This installation step requires sudo on Linux.

Sty also creates .sty directory in your home folder. This is a place where all configuration files are located.

Functions

• Authenticate command line to AWS account, cache and reuse credentials
• Open browser console for the current session (Mac only)
• SSH to instances (jumphost supported)
• Start SSM session to instances (require SSM plugin installed)
• Switch command line proxy settings

Usage

Some Sty commands manipulate environment variables for your current session. To allow current session to be modified, you need to source Sty command, i.e.: . sty login ...

Authentication

To authnticate to an account, run:

. sty login [fqn]

Where fqn is a full account name within the config file hierarchy separated by /. E.g. ga/prod/users. Sty will ask for an MFA token, create session, and assume role in the other account according to the configuration. Once authenticated, credentials will be cached as well as exported to the current session env variables. When the same credentials are requested again form the other session, they will be loaded from the cache.

To logout from the current account, i.e. clean env variables and delete cache file, run:

. sty logout

To get information about currently authenticated session run:

sty info

Browser console (Mac only)

if your session is authenticated, you can open a browser console directly into the current account.

To open browser console, run:

sty console

This will open new session in the default browser. Note, you can't create more then one session in the same browser window. Moreover you must logout from the current console to login to the different role or account.

To log out from the current session in the default browser run":

sty console -l

You can also open browser console in the different browser. Supported browsers are chrome firefox safari and vivaldi

To open a console in Firefox run:

sty console -b firefox

Some browsers support incognito window, which can be enabled with -i switch.

Proxy switcher

To switch a proxy for the current session, run:

. sty proxy [name]

Where name is a proxy name from proxy configuration file ~/.sty/proxy.yaml

To get current proxy settings run the same command without proxy name.

To turm proxy off for the current session, run:

. sty proxy off

Note that you can't use word off for a proxy name in the config file.

Configuration

All config files live in ~/.sty

Uninstallation

gem uninstall sty

Sty will ask if you want to remove ~/.sty with all your configuration. Be careful not to lose your keys.

Caveats

• Credentials are stored in plain unencrypted files
• Opening of a browser console is not working on Linux

TODO

• Create test coverage
• Use keychain on Mac to encrypt stored credentials
• Fix all issues on Linux