lmarty / bash-my-aws

Bash functions for managing AWS resources simply and easily

bash-my-aws

Written to make my life easier, bash-my-aws assists Infrastructure Jockeys using Amazon Web Services from the command line.

This project provides easily memorable commands for realtime control of resources in Amazon AWS. The goal is to reduce the time between intention and effect.

The functions are just as happy being called from your scripts as they are being tapped out on the keyboard.

They make extensive use of the incredibly powerful AWSCLI. It's hoped they may also provide a useful reference to its use.

Prerequisites

• bash
• awscli
• jp (installed automatically if you used python-pip to install awscli)
• jq-1.4 or later (for the cf_diff function)

Installation

As shown below, you may simply clone the GitHub repo and source the files required. (You should probably fork it instead to keep your customisations)

git clone https://github.com/realestate-com-au/bash-my-aws.git ~/.bash-my-aws

Usage

Source the functions you want with something like:

source ~/.bash-my-aws/cloudformation-functions

Typing cf_[TAB] will list available functions for CloudFormation:

$ cf_
cf_asg_instance_ssh  cf_asg_scale_down    cf_delete            cf_events            cf_list              cf_status            cf_validate
cf_asg_instances     cf_asg_scale_up      cf_describe          cf_fail              cf_outputs           cf_tail
cf_asg_name          cf_create            cf_diff              cf_get               cf_param             cf_update

Omitting required arguments will result in Usage instructions being displayed:

$ cf_get
Usage: cf_get stack

You can easily inspect/customize/learn_from what the function is doing:

$ type cf_get
cf_get is a function
cf_get ()
{
    if [ -z "$1" ]; then
        echo "Usage: $FUNCNAME stack-name";
        return 1;
    fi;
    aws cloudformation get-template --stack-name $1 --query TemplateBody
}

For more info on the query syntax used by AWSCLI, check out http://jmespath.org/tutorial.html

Usage examples

cloudformation-functions

Create a stack

This function gives you tab completion for filenames (missing from AWSCLI).

$ cf_create
Usage: cf_create stack [template-file] [params-file]

$ cf_create example      # creates stack called example using example.json 

It's also one of the functions that allows you to omit the template name if it exists in the current directory and matches the stack name with '.json' appended.

It's even smart enough to detect that you've added '-blah' to the stack name.

$ cf_create example-test # creates stack called example-test using example.json 

List stacks

This is basically 'ls' with the ability to filter by a search string

$ cf_list example # call without filter argument to return all stacks
example-app
example-app-test
example-app-dev

See what changes will be made by updating a stack

$ cf_diff
Usage: cf_diff stack [template-file]

$ cf_diff example
--- /dev/fd/63  2014-12-24 15:12:33.000000000 +1100
+++ /dev/fd/62  2014-12-24 15:12:33.000000000 +1100
@@ -113,7 +113,7 @@
         "t2.micro",
         "t2.small"
       ],
-      "Default": "m3.large",
+      "Default": "m3.small",
       "Description": "The type of the EC2 instance you want",
       "Type": "String"
     },

Update a stack

$ cf_update
Usage: cf_update stack [template-file] [params-file]

$ cf_update example # creates stack called example using example.json 
...

Delete a stack

$ cf_delete
Usage: cf_delete stack

$ cf_delete example # deletes stack called example
...

Tail stack events

The create/update tasks call this one but it can also be called directly. It watches events for a stack until it sees them complete or fail.

$ cf_tail who-is-my-am
----------------------------------------------------------------------
|                         DescribeStackEvents                        |
+--------------+----------------------+------------------------------+
|   Resource   |       Status         |            Type              |
+--------------+----------------------+------------------------------+
|  who-is-my-am|  CREATE_IN_PROGRESS  |  AWS::CloudFormation::Stack  |
|  S3Bucket    |  CREATE_COMPLETE     |  AWS::S3::Bucket             |
|  BucketPolicy|  CREATE_COMPLETE     |  AWS::S3::BucketPolicy       |
|  DNS         |  CREATE_COMPLETE     |  AWS::Route53::RecordSet     |
|  who-is-my-am|  CREATE_COMPLETE     |  AWS::CloudFormation::Stack  |
+--------------+----------------------+------------------------------+