EC2 environment switcher script

ec2env.sh

#!/bin/sh

#
# ec2env.sh
# mnmldave
#
# Switch between EC2_PRIVATE_KEY and EC2_CERT environment variables. Licensed under 
# WTFPL v2.0.
#
# Installation (you'll have to open a new terminal after installing):
#
#   $ mkdir ~/.ec2
#   $ curl -L https://raw.github.com/gist/2990031/ > ~/.ec2/ec2env.sh
#   $ echo "source ~/.ec2/ec2env.sh" >> ~/.bashrc # or ~/.zshrc or whatever
# 
# Usage:
# 
#   $ ec2mkenv myec2 private_key.pem cert.pem  # create a new "myec2" environment
#   $ ec2workon myec2                          # activates your "myec2" environment
#

function ec2workon {
  typeset env_name="$1"
  
  if [ "$env_name" = "" ]; then
    echo "Please specify an EC2 environment name:"
    find ~/.ec2/* -type d | xargs -n1 basename
    return 1
  fi
  
  env_dir="$HOME/.ec2/$env_name"
  if [ ! -d "$env_dir" ]; then
    echo "No such environment: $env_name"
    return 1
  fi

  env_private_key="$(/bin/ls "$env_dir"/pk-*.pem | /usr/bin/head -1)"
  if [ ! -f "$env_private_key" ]; then
    echo "Private key not found in directory: $env_dir"
    return 1
  fi
  
  env_cert="$(/bin/ls "$env_dir"/cert-*.pem | /usr/bin/head -1)"
  if [ ! -f "$env_cert" ]; then
    echo "Certificate not found in directory: $env_dir"
    return 1
  fi

  export EC2_PRIVATE_KEY="$env_private_key"
  export EC2_CERT="$env_cert"
  echo "Activated environment: $env_name"
}

function ec2mkenv {
  typeset env_name="$1"
  typeset env_pk="$2"
  typeset env_cert="$3"
  
  if [ -z "$env_name" -o -z "$env_pk" -o -z "$env_cert" ]; then
    echo "Usage: ec2mkenv env_name pk cert"
    return 1
  fi
  
  env_dir="$HOME/.ec2/$env_name"
  if [ -d "$env_dir" ]; then
    echo "Environment already exists: $env_name"
    return 1
  fi
  if [ ! -f "$env_pk" ]; then
    echo "Private key does not exist: $env_pk"
    return 1
  fi
  if [ ! -f "$env_cert" ]; then
    echo "Certificate does not exist: $env_cert"
    return 1
  fi
  
  mkdir -p "$env_dir"
  cp "$env_pk" "$env_dir/pk-$env_name.pem"
  cp "$env_cert" "$env_dir/cert-$env_name.pem"

  echo "Created environment in: $env_dir"
}