How do I replicate these shell commands in Ruby aws-sdk for switching elastic IPs?

Question

I've got elastic IP switching set up on my AWS Linux box. I know the shell commands to switch IP addresses. But I don't know how to do this in Ruby.

Here's the shell commands...

1. Get Instance ID:

   wget -O - ' http://MY.AWS.IP.HERE/latest/meta-data/instance-id ' 2>/dev/null

2. Allocate an elastic IP:

   aws ec2 allocate-address

3. Associate elastic IP with this instance. Use instance and allocation IDs returned from steps 1 and 2.

   aws ec2 associate-address --instance-id INSTANCE_ID_HERE --allocation-id ALLOCATION_ID_HERE

How do I do these with Ruby's aws-sdk gem?

UPDATE

Here's my code now

require 'aws-sdk'
require 'json'
require 'pp'

region = 'REGION NAME'
aws_access_key_id = 'SECRET KEY ID'
aws_secret_access_key = 'SECRET ACCESS KEY'
credentials = Aws::Credentials.new(aws_access_key_id, aws_secret_access_key)
client = Aws::EC2::Client.new(
    region: region,
    credentials: credentials
)
pp client
p '==='

describeAddresses = `aws ec2 describe-addresses`
awsHash = JSON.parse(describeAddresses)
pp awsHash
p '==='

getInstanceID = `wget -O - 'http://MY.AWS.IP.HERE/latest/meta-data/instance-id' 2>/dev/null`
instanceID = getInstanceID.split("\n")[-1]
pp instanceID
p '==='

resp = client.allocate_address({
  domain: "vpc", # accepts vpc, standard
})
pp resp
p '==='

resp2 = client.associate_address({
    instance_id: instanceID,
    allocation_id: resp['allocation_id'],
    allow_reassociation: true#,
})
pp resp2
p '==='

Changes IP, but now I get kicked from XShell when I execute the code. But that's for a different question.

Answer 1

1) you can issue the command in ruby directly and grab the output or you can use httpclient or other lib that can do http requests

2) use allocate_address-instance

3) use associate_address

for 2) and 3) you need to use the AWS Ruby SDK . There's almost a 1:1 mapping between what you're doing in cmd line and what the api calls are