105 - Compute

Where's my Virtual Machine?

Read the Docs

If you want to get a better idea about the object that we will be working with in this module, you can review the docs here:

• Virtual Machine

• NIC

For a more general discussion, take a look here.

Objectives

In this module we'll look at how to configure your VM. We'll describe the core VM settings as well as some of the OS features that are exposed, such as creating a username and password, and adding SSH keys.

Compute Terminology

AWS

Instance

A virtual environment that runs a specific AMI operating system. You can select various Instance types which determine cost and sizing.

NIC

Connects the VM to the network

User Data

Allows the user to pass scripts to perform automated tasks to configure the instance

Azure

Virtual Machine

Azure Virtual Machine running Windows or Linux. You can select various VM sizes which determine cost and sizing.

NIC

Connects the VM to the network

Custom Data

Allows the user to pass scripts to perform automated tasks to configure

Compute Concepts

VM Schema

I'm not sure that this needs much explanation, as it refers to well understood concepts. So set the basic hardware, the image and the credentials.

compute:
  vm:
    webserver-var:
      cores: 1
      memory: 1 GB
      image: bionic
      configure:
        admin:
          username: (( admin_username ))
          public_key: (( admin_public_key ))

Here we define the VM network interface. We associate the NIC with a public and private network interface, associate a subnet and secure it with our defined firewall.

      nics:
        external:
          ips:
            - private:
                type: dynamic
              public:
                type: static
          firewall: fw-external-access
          subnet: subnet-walkthrough

It gets a bit more interesting here; using cloud-init - Powershell, BASH or any other languages that you can leverage through console are also supported - we do a lot of heavy lifting. NGINX is installed, the user is configured and a series of commands are run to bootstrap the webserver. This is extremely powerful, as there is no real limit to what you can do. If you can do it via the CLI, you can do it here.

        userdata:
          type: cloud-init
          content: |
            #cloud-config
            package_upgrade: false
            packages:
              - nginx
            users:
              - name: (( admin_username ))
                groups:
                  - sudo
                sudo: ALL=(ALL) NOPASSWD:ALL
                ssh_authorized_keys:
                  - (( admin_public_key ))
            runcmd:
              - sudo su 
              - echo '(( your_caption ))' > /var/www/html/index.nginx-debian.html