Minor Description
'spark_ec2.py' use boto to control ec2.
And boto can support '~/.aws/credentials' which is AWS CLI default configuration file.
We can check this information from ref of boto.
"A boto config file is a text file formatted like an .ini configuration file that specifies values for options that control the behavior of the boto library.
In Unix/Linux systems, on startup, the boto library looks for configuration files in the following locations and in the following order:
/etc/boto.cfg - for site-wide settings that all users on this machine will use
(if profile is given) ~/.aws/credentials - for credentials shared between SDKs
(if profile is given) ~/.boto - for user-specific settings
~/.aws/credentials - for credentials shared between SDKs
~/.boto - for user-specific settings"
- ref of boto: http://boto.readthedocs.org/en/latest/boto_config_tut.html
- ref of aws cli : http://docs.aws.amazon.com/cli/latest/userguide/cli-chap-getting-started.html
However 'spark_ec2.py' only check boto config & environment variable even if there is '~/.aws/credentials', and 'spark_ec2.py' is terminated.
So I changed to check '~/.aws/credentials'.
