This is a script to simplify EC2 instance interactions, but an example will probably explain my goal better:
./ec2-helper --instance-add ami-ea1e60b8 --instance-wait --instance-knowself --instance-upload --source ~/websitefiles.zip --instance-upload --source ~/virtual.conf --instance-upload --source ~/backup.sql --instance-ssh --sudo --run ~/setup.sh
This command does the following things, in order:
- starts an instance of the ami-eq1e60b8 image
- wait for the instance to finish initialising
- record some basic information about the instance on the instance fs
- upload a zip of website files
- upload a apache virtual config
- upload a mysql backup
- run a setup script on the instance as root (apt-get various packages, downloads various django plugins from their git/svn repos, unzips the website, adds instance info to virtual, restores db)
When the script is finished (10-15 minutes) the website is running

==========HELP COMMANDS ==========
General help
Usage: ./ec2-helper --help


==========KEYPAIR COMMANDS ==========
Create a keypair
Usage: ./ec2-helper --keypair-add <name>

Output the fingerprint of a keypair
Usage: ./ec2-helper --keypair-fingerprint <name>

Output the filepath to the keypair key
Usage: ./ec2-helper --keypair-file <name>

Delete a keypair
Usage: ./ec2-helper --keypair-delete <name>

Output the keypair key
Usage: ./ec2-helper --keypair-show <name>

Output the keypair information provided by the EC2 API
Usage: ./ec2-helper --keypair-list


==========GROUP COMMANDS ==========
Create a group
Usage: ./ec2-helper --group-add <name> [--description <value>]
       --description  Notes about the group

Usage: ./ec2-helper --group-authorize <name> --options <value>
       --options      String containing parameters as required by ec2-authorize
                      OR
                      The name of a variable defined in ec2-helper-config containing
                      those parameters

Deny a group access authorization
Usage: ./ec2-helper --group-revoke <name> --options <value>
       --options      String containing parameters as required by ec2-revoke
                      OR
                      The name of a variable defined in ec2-helper-config containing
                      those parameters

Delete a group
Usage: ./ec2-helper --group-delete <name>

Output the group information provided by the EC2 API
Usage: ./ec2-helper --group-list


==========INSTANCE COMMANDS ==========
Create an instance
Usage: ./ec2-helper --instance-add <ami id> [--keypair <value>] [--type <type>] [--group <name>]
       --keypair      SSH key (DEFAULT: General)
       --type         Instance type (DEFAULT: m1.small)
       --group        Group to assign to the instance (DEFAULT: default)

Wait until the specified instance has transitioned to a stable status (running or terminated)
Usage: ./ec2-helper --instance-wait <instance id> [--tryno <value>] [--trywait <value>]
       --tryno        Number of checks before giving up (DEFAULT: 10)
       --trywait      Wait between tries, in seconds (DEFAULT: 10)

Open an SSH connection to the specified instance
Usage: ./ec2-helper --instance-ssh <instance id> [--keypair <value>] [--user <value>] [--run <value> [--sudo]] [--tryno <value>] [--trywait <value>]
       --keypair      Defaults to the key the instance was initialised with
       --user         DEFAULT: ubuntu
       --run          A file to upload and execute
                      OR
                      A shell command to execute
       --sudo         Execute --run script as SU
       --tryno        Number of tries before giving up (DEFAULT: 10)
       --trywait      Wait between tries, in seconds (DEFAULT: 10)

Upload files to the specified instance using SCP
Usage: ./ec2-helper --instance-upload <instance id> --source <value> --destination <value> [--keypair <value>] [--user <value>]
       --source       Local source path, as defined by SCP
       --destination  Instance destination path, as defined by SCP
       --keypair      Defaults to the key the instance was initialised with
       --user         DEFAULT: ubuntu

Update an instances self-knowledge information (/opt/publicdns)
Usage: ./ec2-helper --instance-knowself <instance id>

Delete the specified instance
Usage: ./ec2-helper --instance-delete <instance id>

Output the instance information provided by the EC2 API
Usage: ./ec2-helper --instance-list

Update instance status using the EC2 API, outputs retrieved statuses
NOTE: known instances that are not listed by the API are updated to 'terminated'
Usage: ./ec2-helper --instance-update [ <instance-id> | - ]
       DEFAULT        Update status of all non-terminated instances
       <instance id>  Update status of specified instance
       -              Update status of all non-terminated instances, and record the
                      status, keypair, and domain for previously unknown instances

Output instance status, i.e. pending / running / shutting down / terminated
Usage: ./ec2-helper --instance-status [ <instance-id> | - ]
       DEFAULT        Show status of all non-terminated instances
       <instance id>  Show status of specified instance
       -              Show status of all recorded instances