305-300 VM Deployment And Provisioning — 15 Questions

Question 1

You are troubleshooting a Packer build that uses the 'shell' provisioner. Which environment variable can you check to see the absolute path to the build directory?

Accepted Answer

PACKER_BUILD_NAME. Packer exposes several variables, and the working directory is often referenced via internal build identifiers, but 'PACKER_BUILD_NAME' is a standard environment variable provided by Packer.

Answer

PWD

Answer

PACKER_BUILDER_TYPE

Answer

BUILD_DIR

Question 2

Which TWO commands in Packer can be used to manage plugin installations?

Accepted Answer

packer init. 'packer init' is used to download and initialize required plugins, and 'packer plugins' is used to list them.

Answer

packer upgrade

Answer

packer update

Answer

packer install

Question 3

You are using Packer to automate a build. You notice the build fails because the 'communicator' cannot connect. Which type of communicator is most suitable for a KVM-based build where SSH is not yet configured?

Accepted Answer

none. The 'none' communicator is used when the builder handles the image creation without needing remote access, or 'ssh' if the guest OS supports it. However, if the build relies on console output/keystrokes, the 'none' communicator is often used alongside the boot command.

Answer

ssh

Answer

http

Answer

winrm

Question 4

In a Packer build process for OpenStack, which 'post-processor' type is typically used to upload the resulting image to the Glance image service?

Accepted Answer

openstack. The 'openstack' post-processor is designed to handle the registration of the image into the OpenStack Glance service.

Answer

manifest

Answer

shell-local

Answer

compress

Question 5

When using Vagrant to manage a libvirt-based provider, which command verifies that the virtual machine is currently running and identifies the provider in use?

Accepted Answer

vagrant status. 'vagrant status' provides the current state of the machine and the provider used for that specific instance.

Answer

vagrant up

Answer

vagrant validate

Answer

vagrant box list

Question 6

You are configuring cloud-init to inject an SSH key into a new VM. Which directive in the configuration metadata ensures the key is added to the correct user's authorized_keys file?

Accepted Answer

ssh_authorized_keys. The 'ssh_authorized_keys' directive within the user object specifies which public keys should be injected into the ~/.ssh/authorized_keys file for that user.

Answer

users.ssh_key

Answer

ssh_keys

Answer

authorized_keys_file

Question 7

Which file in a Vagrant project directory is processed by default to define the virtual environment configuration?

Accepted Answer

Vagrantfile. Vagrant looks for a file named 'Vagrantfile' in the directory where the 'vagrant' command is executed.

Answer

settings.json

Answer

provision.sh

Answer

config.yml

Question 8

You are using Packer to build a custom image for KVM. Which HCL2 block is specifically required to define the virtualization parameters like memory and CPU for the builder?

Accepted Answer

qemuargs. The 'qemu' builder in Packer utilizes specific configuration blocks to define virtual hardware settings when interfacing with KVM/QEMU.

Answer

provisioners

Answer

post-processors

Answer

boot_command

Question 9

When defining a Vagrant network configuration for a libvirt provider, which mode allows the VM to receive an IP address directly from the physical network's DHCP server?

Accepted Answer

public_network. The 'public_network' mode bridges the VM's interface to the host's physical network interface, allowing it to act like a physical machine on that segment.

Answer

nat

Answer

forwarded_port

Answer

private_network

Question 10

A cloud-init configuration file is failing to apply the 'write_files' module. Which log file on the target instance should you examine to diagnose the parsing error?

Accepted Answer

/var/log/cloud-init.log. Cloud-init logs all activities to /var/log/cloud-init.log, while /var/log/cloud-init-output.log captures stdout and stderr from the modules.

Answer

/var/log/syslog

Answer

/var/log/messages

Answer

/var/log/auth.log

Question 11

What is the primary function of the cloud-init 'runcmd' module?

Accepted Answer

Running arbitrary shell commands. The 'runcmd' module is used to execute arbitrary shell commands during the boot process of an instance.

Answer

Setting the system locale

Answer

Configuring users

Answer

Installing software packages

Question 12

When provisioning with Vagrant, which command is best used to apply changes to a configuration (like adding a new shell script) without destroying the existing virtual machine?

Accepted Answer

vagrant provision. 'vagrant provision' triggers the configured provisioners (shell, ansible, etc.) on a running VM without destroying it.

Answer

vagrant halt

Answer

vagrant reload

Answer

vagrant up

Question 13

You need to ensure that a specific package is installed during the first boot of a cloud instance. Which cloud-init key should be added to the configuration?

Accepted Answer

packages. The 'packages' list under cloud-init config allows specifying a list of packages to be installed by the system package manager.

Answer

yum_install

Answer

software

Answer

install_packages

Question 14

Which Packer builder is most appropriate for creating an image specifically for Amazon Web Services (AWS)?

Accepted Answer

amazon-ebs. The 'amazon-ebs' builder is the standard choice for creating Amazon Machine Images (AMIs).

Answer

virtualbox-iso

Answer

qemu

Answer

docker

Question 15

In a Vagrantfile, which method is used to pass environment variables into the guest virtual machine during the provisioning phase?

Accepted Answer

config.vm.provision "shell", env: { "VAR" => "value" }. The 'config.vm.provision "shell"' block accepts an 'env' hash to define environment variables for the shell script.

Answer

config.env.set

Answer

config.vm.env

Answer

vagrant.env.set