Add GetPasswordData operation for EC2 instances

[jen20]

Description

This operation allows the user to obtain a copy of the auto-generated Administrator password for an instance running Windows, encrypted using the key-pair specified on instance launch.

A test has been added using the example from the documentation, but with the response updated to reflect the actual time format passed in current usage.

Example usage

package main

import (
    "fmt"
    "github.com/mitchellh/goamz/aws"
    "github.com/mitchellh/goamz/ec2"
    "log"
)

func main() {
    auth, err := aws.EnvAuth()
    if err != nil {
        log.Fatal(err)
    }

    client := ec2.New(auth, aws.USEast)

    resp, err := client.GetPasswordData("i-7435208e")
    if err != nil {
        log.Fatal(err)
    }

    log.Print(fmt.Sprintf("%+v", resp))
}

Example output (password available):

015/03/21 12:42:50 &{RequestId:ae0976ec-bf3e-4f29-8b76-b2909b53b55a InstanceId:i-7435208e Timestamp:2015-03-21 16:39:38 +0000 UTC PasswordData:
c1jbhR3b7cApaiPX2X8BdqqGo0LlY3jsFL5ods3yrp86UXhznv1Ae3rlNjxAKVFJOCGcbnDkV1dWU1CkOrc1proiWKJVefQsNXSKfVf/GW5eq+jag0C2jG2LITeKoio8jovhVMqQvtxP+DC+p21XWfBwXAuF5shAG+ULvx6dj1/7HJuDdcJwkptEswvIg95HOyfx29h6gTMDx1JwEHGDasWTJzrUp7tGESl+6LPS7SRI5SlrE1RrNn/3tsJstBi5yLKb7MjKlCHf6FNJYrlt1eXcA3gSAeBB699UjhXv1M5x6SSqmVmLcNlPeFfoOBbZ8vKS458p7Zj00OF3GJvGpA==
}

Example output (password not yet available):

2015/03/21 12:39:09 &{RequestId:a3df9040-beae-413c-862d-7833eb5de5e7 InstanceId:i-7435208e Timestamp:2015-03-21 16:38:16 +0000 UTC PasswordData:}

[jen20]

@mitchellh Is this likely to be accepted given the new libs? packer-community/packer-windows-plugins#39 depends on it - I can likely work around this if necessary though.

[mefellows]

Hi @mitchellh, is this likely to be merged anytime soon? Looking to follow up on the above PR for Packer Windows Plugins. If not, we'll work on another strategy.

[davidvasandani]

+1

[jen20]

You can now do this with the official AWS SDK:

resp, err := ec2conn.GetPasswordData(&ec2.GetPasswordDataInput{
    InstanceId: aws.String("instanceId"),
})

[NoumanSaleem]

Seems like it's implemented https://github.com/mitchellh/packer/blob/51002e8c6fa8d367e02e074701efa3974ee079cb/builder/amazon/common/step_get_password.go#L113