Add support for AWS config and credential files

[alexconst]

When either access_key_id or secret_access_key are not set it will attempt to read from environment variables, if those are empty then it will attempt to read from config and credentials.
It allows choosing a profile (by default it's "default") and an "info" directory (by default $HOME/.aws).
Supported information: region, aws_access_key_id, aws_secret_access_key and aws_session_token.

Closes issue #151

[chriswgerber]

Thanks for the work getting this started. We've been looking for something like this as well.

Two things:

1. If you're trying to mimic the way the AWS CLI works, config and credential filepaths should fall back to declared values in AWS_SHARED_CREDENTIALS_FILE and AWS_CONFIG_FILE environmental variables before defaulting to ~/.aws/credentials or ~/.aws/config.
2. You can clean up the config/credential file parser by using an INI/PythonConfig parser such as https://rubygems.org/gems/configparser or https://rubygems.org/gems/iniparse

[alexconst]

@ThatGerber I've implemented 1) and 2).
Let me know if it works for you.

[alexconst]

Updated description:
This PR reads AWS config and credentials.
Behaviour aims to mimic what is described in AWS documentation:
http://docs.aws.amazon.com/cli/latest/userguide/cli-chap-getting-started.html
http://docs.aws.amazon.com/cli/latest/topic/config-vars.html
Which is the following (stopping at the first successful case):

1. read config and credentials from environment variables
2. read config and credentials from files at location defined by environment variables
3. read config and credentials from files at default location

The mandatory fields for a successful "get credentials" are the id and the secret keys.
Region is not required since Config#finalize falls back to sensible defaults.
The behaviour is all-or-nothing (ie: no mixing between vars and files).

It also allows choosing a profile (by default it's [default]) and an "info"
directory (by default $HOME/.aws), which can be specified in the Vagrantfile.
Supported information: region, aws_access_key_id, aws_secret_access_key, and aws_session_token.

[alexconst]

@rtyler Any chance for this and the other PRs to get some love?

[alexconst]

@mitchellh is anyone actively maintaining this project?

[madsem]

@mitchellh don't understand why packer is reading ~/.aws/credentials but vagrant-aws is not. Please look into merging

[rtyler]

This gem is referred to in vagrant-aws/config.rb so I'm not clear on why it is in the :development group of this Gemfile instead of as a dependency listed in the gemspec proper.

[alexconst]

@rtyler I believe I fixed the gemspec issue.

[alexconst]

@rtyler any updates on this?

[lantins]

If possible, I'd love to see a new gem released that includes this change.

[kenorb]

I have this error after applying this PR:

$ vagrant up --provider=aws
~/.vagrant.d/gems/gems/vagrant-aws-0.7.0/lib/vagrant-aws/config.rb:537:in `read_aws_files': undefined method `[]' for nil:NilClass (NoMethodError)
    from ~/.vagrant.d/gems/gems/vagrant-aws-0.7.0/lib/vagrant-aws/config.rb:513:in `get_aws_info'
    from ~/.vagrant.d/gems/gems/vagrant-aws-0.7.0/lib/vagrant-aws/config.rb:326:in `finalize!'

My config file is like:

[default]
region = us-east-1
output = text

[testing]
region = us-east-1
output = text

What's wrong?

[chriswgerber]

@kenorb You are configuring your profiles incorrectly, that's why it's not working.

http://docs.aws.amazon.com/cli/latest/userguide/cli-chap-getting-started.html#cli-multiple-profiles

The method is that config files should have [profile NAME]. Credentials files are set up as [NAME].