speculate

Tool for assuming roles in AWS accounts

To assume the "admin" role in the local account:

speculate env admin

Speculate is designed to be a bare-bones implementation of the underlying AWS role management calls, so that other tools can layer on top of it. speculate env uses the current environment's creds (set in standard AWS environment variables or ~/.aws/credentials or similar) to assume the named role, and it returns the resulting creds in environment export format.

To use these creds, you probably want to do the following:

eval $(speculate env admin)

That will source the new creds into your environment.

A console subcommand is also provided, for creating a URL for AWS's console:

speculate console

This uses the current environment's credentials, and can thus be chained together like so:

eval $(speculate admin) && open $(speculate console)

The env command accepts some options for controlling which account to assume a role on, as well as for MFA and other assumption settings:

# speculate env --help
Generate temporary credentials, either by assuming a role or requesting a session token

Usage:
  speculate env [ROLENAME] [flags]

Flags:
  -a, --account string   Account ID to assume role on (defaults to source account)
  -h, --help             help for env
  -l, --lifetime int     Set lifetime of credentials in seconds. For SessionToken, must be between 900 and 129600 (default 3600). For AssumeRole, must be between 900 and 43200 (default 3600)
  -m, --mfa              Use MFA when assuming role
      --mfacode string   Code to use for MFA
      --policy string    Set a IAM policy in JSON for the assumed credentials
  -s, --session string   Set session name for assumed role (defaults to origin user name)

speculate is released under the MIT License. See the bundled LICENSE file for details.