运行describe region
命令时出现以下错误。算我一个Ubuntu 12.04
$ ec2-describe-regions
Required option '-K, --private-key KEY' missing.
我已经设置了以下几行
$ export EC2_HOME=<path-to-tools>
$ export PATH=$PATH:$EC2_HOME/bin
$ export AWS_ACCESS_KEY=your-aws-access-key
$ export AWS_SECRET_KEY=your-aws-secret-key
你能帮我么?