Is there a way to get the number of cores and amount of memory of an instance type from the command line aws tool?
Basically I want to access the data on http://aws.amazon.com/ec2/instance-types/ programmatically.
Not officially. But the incredible Mitch Garnaat has a Github repository with "missingcloud" bits. On that list is instance information. You can pick that out with your favorite language. Here's an example with a bit of jq. (this is imperfect, maybe someone can help split these into instance:ramMB rows?)
$ curl --silent https://raw.githubusercontent.com/garnaat/missingcloud/master/aws.json | jq '[.services."Elastic Compute Cloud".instance_types|to_entries|.[]|.key,.value.ramMB]' | head -9
[
"c1.medium",
1700,
"c1.xlarge",
7000,
"c3.2xlarge",
15000,
"c3.4xlarge",
30000,