Server configuration

This step concerns the configuration of virtual machines, such as the configuration of hardening, directories, disk mounting, network configuration (firewall, proxy, and so on), and middleware installation.

There are different configuration tools, such as Ansible, PowerShell DSC, Chef, Puppet, and SaltStack. Of course, there are many more, but, in this book, we will look at, in detail, the use of Ansible to configure a virtual machine.

To optimize server provisioning and configuration times, it is also possible to create and use server models, also called images, that contain all of the configuration (hardening, middleware, and so on) of the servers. It will be during the provisioning of the server that we will indicate the template to use, and hence, we will have, in a few minutes, a configured server ready to be used.

There are also many IaC tools for creating server templates, such as aminator (used by Netflix) or HashiCorp Packer.

Here is an example of Packer file code that creates an Ubuntu image with package updates:

{
"builders": [{
     "type": "azure-arm",
     "os_type": "Linux",
     "image_publisher": "Canonical",
     "image_offer": "UbuntuServer",
     "image_sku": "16.04-LTS",
     "managed_image_resource_group_name": "demoBook",
     "managed_image_name": "SampleUbuntuImage",
     "location": "West Europe",
     "vm_size": "Standard_DS2_v2"
 }],
 "provisioners": [{
     "execute_command": "chmod +x {{ .Path }}; {{ .Vars }} sudo -E sh '{{ .Path }}'",
     "inline": [
     "apt-get update",
     "apt-get upgrade -y",
     "/usr/sbin/waagent -force -deprovision+user && export HISTSIZE=0 && sync"
 ],
 "inline_shebang": "/bin/sh -x",
 "type": "shell"
 }]
}

This script creates a template image for the Standard_DS2_V2 virtual machine based on the Ubuntu OS (the builders section). Additionally, Packer will update all packages during the creation of the image with the apt-get update command and, after this execution, Packer deprovisions the image to delete all user information (the provisioners section).