Using Amazon AWS with Juju

Overview

To manage workloads on Amazon AWS, there are three steps:

1. Create an IAM User account with the ability to modify EC2 resources
2. Use juju add-credential to register that account with Juju
3. Create a Juju controller

Create an AWS user account

Log in to the AWS console

Visit the AWS Management Console and log in.

Create a user account with full EC2 access

Select My Security Credentials from the drop-down menu:

If you see a pop-up with the button “Get Started with IAM Users” go ahead and click on it and then “Add user”. If you do not see such a pop-up then, in the top bar, choose Services > IAM > Users > Add user:

Enter a name for your user and set Programmatic access as the AWS access type before clicking Next: Permissions to continue.

On the next page create a group which, by default, will contain your new user. Name the group and select one or many pre-existing policies that correspond to your requirements. The AmazonEC2FullAccess policy will be sufficient for most use cases.

Here we’ve chosen AdministratorAccess, which is the most privileged policy available. This could be useful if we wish to use the juju trust to allow charms to provision any AWS service later on.

Click the Create group button and then Next: Tags. Tags are optional is skipped here by clicking Next: Review straight away. On the next page click Create user.

Successfully creating a new user results in a Success message appear:

Download credentials for Juju registration

Click on the Download .csv button to get a copy of this account’s security credentials. The contents of this file will look similar to this:

jlaurin,,AKIAIFII8EH5BOCYSJMA,WXg6S5Y1DvwuGt72LwzLKnItt+GRwlkn668sXHqq,https://466421367158.signin.aws.amazon.com/console

Adding credentials

There are multiple methods for adding security credentials to Juju. Each processwill require two fields from the CSV file that you downloaded from the user account (Hyphens indicate that the field is unnecessary).

-,-,<access-key>,<secret-key>,-

Alternately, you can use your credentials with Juju as a Service, where charms can be deployed within a graphical environment that comes equipped with a ready-made controller.

Using the interactive method

Credentials can be added with the juju add-credential command:

juju add-credential aws

An example session:

Enter credential name: jlaurin

Using auth-type "access-key".

Enter access-key: AKIAIFII5EH5FOCYZJMA

Enter secret-key: ******************************

Credential "jlaurin" added locally for cloud "aws".

Using a file

A YAML-formatted file, say mycreds.yaml, can be used to store credential information for any cloud. This information is then added to Juju by pointing the add-credential command to the file:

juju add-credential aws -f mycreds.yaml

See section Adding credentials from a file for guidance on what such a file looks like.

Using environment variables

With AWS you have the option of adding credentials using the following environment variables that may already be present (and set) on your client system:

AWS_ACCESS_KEY_ID
AWS_SECRET_ACCESS_KEY

Add this credential information to Juju in this way:

juju autoload-credentials

For any found credentials you will be asked which ones to use and what name to store them under.

On Linux systems, files $HOME/.aws/credentials and $HOME/.aws/config may be used to define these variables and are parsed by the above command as part of the scanning process.

For background information on this method read section Adding credentials from environment variables.

Creating a controller

You are now ready to create a Juju controller for cloud ‘aws’:

juju bootstrap aws aws-controller

Above, the name given to the new controller is ‘aws-controller’. AWS will provision an instance to run the controller on.

For a detailed explanation and examples of the bootstrap command see the Creating a controller page.

AWS specific features

Awareness of regions and instance types

Juju contains built-in knowledge of AWS regions, instance types and their capabilities.

juju show-cloud --local aws

Replacing the --local option with --controller to report regions known to a controller.

Use juju update-public-clouds to update Juju’s knowledge of new AWS regions as they are available.

Custom tags

Consistent naming, tagging, and the ability to add user-controlled tags to created instances. See Instance naming and tagging for more information.

Instance type selection

Juju’s default AWS instance type is m3.medium. A different type can be selected via a constraint: juju add-machine --constraints 'instance-type=t2.medium'. For more information see Constraints. You can also view the list of Amazon EC2 instance types.

Support for Virtual Private Cloud (VPC) functionality

A controller can be placed in a specific virtual private cloud (VPC). See Passing a cloud-specific setting for instructions.

Next steps

A controller is created with two models - the ‘controller’ model, which should be reserved for Juju’s internal operations, and a model named ‘default’, which can be used for deploying user workloads.

See these pages for ideas on what to do next:

• Juju models
• Applications and charms