Updated documentation

README.md

@@ -1,2 +1,26 @@
 # aws-role
+
 Small CLI utility to assume a role in AWS
+
+Using this utility, a command can be run using an assumed role, as opposed to your default profile. The role assumption is not persisted to your shell, so subsequent requests must also use this utility.
+
+
+## Installation
+
+### From source
+
+Currently, the only way to install the utility is from source. It requires you to have [go](https://golang.org) installed on your system.
+
+`go get github.com/ryanfrench/aws-role`
+
+## Usage
+
+### Assume a role
+
+`aws-role --role-arn [role] [command]`
+
+This will assume `[role]` and then run `[command]` using that role.
+
+### Help
+
+`aws-role --help`

cmd/root.go

@@ -22,13 +22,14 @@ var (
 )
 
 var rootCmd = &cobra.Command{
-	Use:   "aws-role [command]",
+	Use:   "aws-role --role-arn [role] [command]",
 	Short: "Assume a role in AWS and optionally run a command",
 	Long: `
-Assume a role within AWS. This will set your AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY and AWS_SESSION_TOKEN environment variables, allowing you to run a command using the new role. If no command is provided, they will be exported into your current session.
+Run a command within the context of assuming a role. This is not persistent, and will only affect the command that is passed in.
 
+e.g.
 
-Use "aws-role [command] --help" for more information about a command.`,
+aws-role  --role-arn=arn:aws:iam::1234567890:role/my-role aws s3 ls`,
 	Run:     run,
 	Version: "0.1.0",
 	Args:    cobra.MinimumNArgs(1),