AWS Free Tier accounts are limited to t2.micro instances. As juju itself will default to medium instance types, a new user trying out juju using an AWS free tier account will fail to bootstrap, and instead return the following message:
"ERROR failed to bootstrap model: cannot start bootstrap instance: cannot run instances: Your account is currently being verified. Verification normally takes less than 2 hours. Until your account is verified, you may not be able to launch additional instances or create additional volumes. If you are still receiving this message after more than 2 hours, please let us know by writing to <email address hidden>. We appreciate your patience. (PendingVerification)"
The message displayed is incorrect in this case as the verification isn't the issue. Rather it's the idea the account cannot use any other instance type besides t2.micro as juju is presumably asking aws for medium.
Can we support these free tier accounts that are limited to specific instance types? It would be useful to default to t2.micro for these accounts. The concern with using micro instances is charm compatibility -- perhaps juju could warn about this when it switches the default because of the limited account.
I was able to bootstrap after receiving the above message by running
juju bootstrap aws aws --constraints 'instance-type=t2.micro'
Removing 2.1 milestone as we will not be addressing this issue in 2.1.