COA Architecture and Services 3 — Questions and Answers
Question 1: What does the OpenStack Heat service use to describe infrastructure as code?
- YAML-based Ansible playbooks
- HOT (Heat Orchestration Templates) (Correct answer)
- Terraform HCL files
- JSON CloudFormation templates only
Correct answer: HOT (Heat Orchestration Templates)
Heat uses its own Heat Orchestration Template (HOT) format in YAML to describe cloud infrastructure as code.
Question 2: Which component handles the OpenStack Identity service's token validation in a Fernet token setup?
- A central token database
- Symmetric keys distributed across Keystone nodes (Correct answer)
- An external HSM exclusively
- Nova's scheduler
Correct answer: Symmetric keys distributed across Keystone nodes
Fernet tokens are validated using symmetric cryptographic keys that are distributed and rotated across all Keystone nodes without requiring a token database.
Question 3: In OpenStack Neutron, what is an 'external network' used for?
- Connecting instances on the same tenant
- Providing floating IPs and routing to the internet (Correct answer)
- Isolating management traffic
- Creating VXLAN tunnels between compute nodes
Correct answer: Providing floating IPs and routing to the internet
External networks in Neutron represent the upstream network (internet-facing) from which floating IPs are allocated for external connectivity.
Question 4: What is the function of the Glance registry service?
- Stores raw image data in Swift
- Provides a metadata catalog for images (deprecated in newer releases) (Correct answer)
- Authenticates users accessing images
- Converts image formats on upload
Correct answer: Provides a metadata catalog for images (deprecated in newer releases)
The Glance registry was a separate service for storing image metadata, though it was deprecated and its functionality merged into glance-api in newer releases.
Question 5: Which OpenStack service provides key management and secrets storage?
- Keystone
- Barbican (Correct answer)
- Castellan
- Vault
Correct answer: Barbican
Barbican is the OpenStack Key Manager service that securely stores and manages secrets, keys, and certificates.
Question 6: What is the primary purpose of the OpenStack Placement service?
- Scheduling network resources across availability zones
- Tracking resource provider inventories and allocations for scheduling (Correct answer)
- Managing physical server BIOS settings
- Assigning floating IPs to instances
Correct answer: Tracking resource provider inventories and allocations for scheduling
The Placement service tracks resource provider inventories (CPU, RAM, disk) and allocations to support Nova's scheduling decisions.
Question 7: In OpenStack, which protocol does Cinder typically use to attach volumes to instances over a network?
- NFS
- iSCSI (Correct answer)
- FTP
- SFTP
Correct answer: iSCSI
Cinder commonly uses iSCSI to attach block storage volumes from the storage backend to Nova compute nodes.
COA Architecture and Services 3
What does the OpenStack Heat service use to describe infrastructure as code?