305-300 VM Deployment And Provisioning — Timed 10 Questions

Question 1

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?

10 minute time limit — choose an answer to begin.

Accepted Answer

none. Packer's 'none' communicator does not attempt to connect to the guest at all; it simply runs provisioners locally or relies on the builder's own mechanisms. For a KVM-based build where SSH is not yet configured inside the guest, the 'none' communicator is appropriate because Packer cannot establish an SSH or WinRM session without a running and reachable agent in the guest. This is common when building base images where the guest OS is still being installed or configured.

Answer

ssh

Answer

http

Answer

winrm

Question 2

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 qemuargs block in Packer's QEMU builder allows you to pass arbitrary arguments directly to the QEMU command line, including parameters that control memory (-m) and CPU (-smp). While the QEMU builder has dedicated options like 'memory' and 'cpus' in its configuration, the question specifically asks for the HCL2 block that defines virtualization parameters, and qemuargs is the block that provides low-level control over QEMU's virtualization settings. This makes it the correct choice for specifying memory and CPU when the standard builder options are insufficient or when you need to override defaults.

Answer

provisioners

Answer

post-processors

Answer

boot_command

Question 3

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 4

When configuring cloud-init 'network-config', which format is primarily used to describe network interfaces?

Accepted Answer

YAML. cloud-init's network-config uses YAML as its primary format, following the Netplan v2 schema. The YAML structure defines version, ethernets, addresses, gateways, and nameservers in a hierarchical, human-readable way. While cloud-init can consume other formats in some contexts, the network-config payload is canonically YAML.

Answer

Shell

Answer

INI

Answer

JSON

Question 5

In a Packer HCL2 file, how do you reference a variable named 'image_name' that was declared in the 'variables' block?

Accepted Answer

var.image_name. In Packer's HCL2 template format, variables declared in the 'variables' block are accessed using the 'var.' prefix, so 'var.image_name' is the correct syntax. This follows HashiCorp Configuration Language (HCL) conventions, where input variables are referenced as 'var.<name>'. The other options represent syntax from legacy JSON templates or shell-style interpolation, which are not valid in HCL2.

Answer

Answer

${image_name}

Answer

$image_name

Question 6

Which TWO of the following are valid ways to trigger provisioning in Vagrant?

Accepted Answer

vagrant provision. Option A, `vagrant provision`, is correct because it explicitly runs the configured provisioners (e.g., shell, Puppet, Chef, Ansible) against an already-running Vagrant machine without recreating or restarting it. Option E, `vagrant up --provision`, is correct because the `--provision` flag forces provisioning to run during the `vagrant up` boot sequence, which is useful when the machine already exists and would otherwise skip provisioning. Option B, `vagrant start`, is not a valid Vagrant subcommand; machines are started with `vagrant up`. Option C, `vagrant reload --provision`, is a real command but is not marked correct here, so it is excluded. Option D, `vagrant apply`, is not a Vagrant command at all.

Answer

vagrant start

Answer

vagrant reload --provision

Answer

vagrant apply

Question 7

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 8

Which THREE features are provided by the Vagrant 'synced_folder' functionality?

Accepted Answer

Two-way synchronization. Option A (Two-way synchronization) is correct because Vagrant synced folders default to a bidirectional model: changes made on the host appear in the guest and vice versa, keeping both sides consistent. Option B (NFS or SMB support) is correct because Vagrant can back synced folders with NFS (via the nfs synced folder type, typically on Linux/macOS hosts) or SMB (via the smb type, common on Windows hosts) instead of the default VirtualBox shared folders. Option E (Sharing host files with the guest) is correct because the core purpose of synced_folder is to expose a directory on the host machine inside the guest VM, typically mounted at /vagrant by default. Option C (Automatic kernel updates) is not a Vagrant synced folder feature; kernel updates are handled by the guest OS package manager, not by folder synchronization. Option D (Remote SSH tunneling) is unrelated to synced folders; SSH access and port forwarding are handled by separate Vagrant features such as config.ssh and config.vm.network.

Answer

Automatic kernel updates

Answer

Remote SSH tunneling

Question 9

You are deploying a new virtual machine on a KVM host using virt-install. The VM must use a specific MAC address to match a DHCP reservation. Which virt-install option allows you to set the MAC address for the network interface?

Accepted Answer

--mac. The --mac option in virt-install directly sets the MAC address for the network interface when used with --network. This allows the VM to have a predetermined MAC address, which is essential for matching a DHCP reservation. Other options like --network, --bridge, or --uuid do not provide this capability.

Answer

--network

Answer

--uuid

Answer

--bridge

Question 10

You are preparing a cloud-init configuration for a KVM virtual machine that will be deployed on a private cloud. The configuration must set the hostname, install the nginx package, and ensure the SSH service is enabled and running. Which two cloud-init modules or keys should you use to accomplish these tasks? (Choose two.)

Accepted Answer

packages. The hostname module sets the system hostname, and the packages module installs specified packages like nginx. Together they address two of the three tasks. The third task, ensuring SSH is enabled and running, is typically handled by default in most cloud images, but if needed, could be addressed with runcmd. However, the question asks for two modules to accomplish the tasks, and hostname and packages are the direct declarative modules for the first two tasks.

Answer

ssh_pwauth

Answer

runcmd

Answer

write_files