Add boto3action to aws pack

[xydinesh]

I create this pull request as a result of discussion happened in, StackStorm-Exchange/exchange-incubator#10. Main features in this pull request are,

• Ability to assume_role for cross account access
• Ability to specify region for cross region access

For example, I have a st2 deployment in aws account 123456 and us-east-1. I want to deploy VPC in account 456789 and us-west-1.

     assume_role:
        action: aws.assume_role
        input:
           role_arn: “arn:aws:iam:456789:role/st2_role”
        publish:
          credentials: <% task(assume_role).result.result %>
       on-success:
         - create_vpc
    
    create_vpc:
      action: aws.boto3action
      input:
        service: ec2
        action_name: create_vpc
        region: "us-west-1"
        params: <% dict(CidrBlock => "10.0.0.0/16", InstanceTenancy => "default") %>
        credentials: <% $.credentials %>
      publish:
          vpc_id: <% task(create_vpc).result.result.Vpc.VpcId %>
      on-success:
        - create_subnet

    create_subnet:
      action: aws.boto3action
      input:
        service: ec2
        region: "us-west-1"
        action_name: create_subnet
        params: <% dict(AvailabilityZone =>"us-west-1a", CidrBlock =>"10.0.0.0/24", VpcId => $.vpc_id) %>
        credentials: <% $.credentials %>
      publish:
        subnet_ids: <% task(create_subnets).result.result.Subnet.SubnetId %>
      on-success:
         - create_igw

     create_igw:
        action: aws.boto3action
        input:
          service: ec2
          action_name: create_internet_gateway
          region: <% $.region %>
          credentials: <% $.credentials %>
        publish:
          igw_id: <% task(create_igw).result.result.InternetGateway.InternetGatewayId %>

In addition, aws.boto3action created with following opinions.

• aws credentials
  Boto3 is the official SDK for AWS. As a user/developer, If I have boto3 configured I expect aws pack to work without doing any additional configuration. For example,

st2 pack install aws
st2 run aws.boto3action service="ec2" action_name="decribe_vpcs" region="us-west-1"

In addition, if I want to use use boto3 profiles

st2 run aws.boto3action service="ec2" action_name="decribe_vpcs" region="us-west-1" env="AWS_PROFILE=production"

• yaml generation
  Long term, I don’t believe yaml generation scale based on the number of services AWS have and introduce. In addition, IMO Boto3 documentation is detailed, has examples. Having yaml for each action is redundant and add no value to the end user.

• pack maintenance

  Since there are no yaml to generate, this pack should be easy to maintain. Any new service boto3 introduce, available to pack user right away.

[warrenvw]

Ablity -> Ability

[xydinesh]

Fixed in the latest commit.

[warrenvw]

Ability -> Ability

[xydinesh]

Fixed in the latest commit.

[warrenvw]

I'm asking for a few minor tweaks. Before we merge boto3 into master, we'll make sure that all outstanding issues are resolved, and users are notified of the upcoming changes.

[xydinesh]

@warrenvw Thanks for approving changes. Please let me know if you need anything from me to make progress on this PR.

[humblearner]

lgtm