Learn OpenStack - Horizon Dashboard & OpenStack CLI Mastery

#Introduction

Up to episode 10, you operated OpenStack almost entirely through the CLI. But there's one door you haven't opened: Horizon, OpenStack's official web dashboard. Horizon isn't an alternative — it's another way of interacting with the same APIs. In this episode you'll become fluent in both.

Episode 11 covers both sides of operating OpenStack: navigating the Horizon Dashboard for visual management, and mastering the OpenStack CLI for automation and efficiency — including the openrc environment file, the unified openstack CLI, and output formatting for scripting.

#Horizon Web Dashboard

#Navigating Between Modules

Horizon organizes its UI to follow OpenStack's project structure. After logging in, you'll see a navigation panel with the main modules:

• Project > Compute: Instances, Images, Key Pairs.
• Project > Network: Network Topology, Networks, Routers, Floating IPs, Security Groups.
• Project > Volume: Volumes, Snapshots, Backups.
• Identity: Projects, Users, Groups, Roles (admin only).

Project
 ├── Compute → Instances, Images, Key Pairs
 ├── Network → Topology, Networks, Routers, Floating IPs
 ├── Volume  → Volumes, Snapshots, Backups
Identity → Projects, Users, Groups, Roles (admin)

Every menu is a visual representation of the same APIs the CLI uses — understanding this map keeps you from getting lost in the UI.

#Creating an Instance Through the GUI

openstack endpoint list --interface public --service dashboard

Open the dashboard URL (usually http://IP/dashboard), then follow the flow: Project > Compute > Instances > Launch Instance. Fill in a name, choose the image and flavor in the Source and Flavor tabs, pick the network in the Networks tab, then click Launch Instance. Within seconds the instance appears in the list — just like openstack server create.

#Managing Networks and Volumes via the GUI

The same pattern applies to networking: Project > Network > Networks > Create Network to create a network and subnet at once, or Project > Volume > Volumes > Create Volume to create a volume. The relationship between UI and CLI is one-to-one — every button in Horizon calls a single openstack command behind the scenes.

#OpenStack CLI Advanced Usage

#The openrc Environment File

The CLI needs credentials every time it's called. Instead of typing --os-username over and over, OpenStack uses an environment file that you source:

source admin-openrc.sh
openstack token issue -f value -c id

source admin-openrc.sh exports variables such as OS_AUTH_URL, OS_USERNAME, OS_PROJECT_NAME, and OS_PROJECT_DOMAIN_NAME. DevStack provides openrc — in episode 0 you used source /opt/stack/devstack/openrc admin admin. Once sourced, every openstack command immediately knows the environment.

#The Unified openstack CLI

Since the Mitaka release, all services use one unified command:

openstack automatically determines the target service from the first sub-command. This simplifies operations that used to be scattered across separate clients like nova, neutron, and cinder.

#Output Formatting for Scripting

The default CLI output is a table that's pleasant for humans but not for parsing. Use the format flags:

openstack server list -f table
openstack server list -f value -c ID -c Name
openstack server list -f json | jq '.[0].name'

The openstack server list -f value -c ID -c Name command outputs only ID and Name — perfect for scripting. The -f json combination with jq is the main weapon of OpenStack automation.

#Combining UI and CLI

#When to Use Which

The practical rule: GUI for exploration and one-off operations, CLI for repeated operations and automation. You should be comfortable switching between them, because production uses both together — verify in Horizon, run mass operations in the CLI.

for id in $(openstack server list -f value -c ID); do
  openstack server show "$id" -f value -c status
done

The loop above uses -f value to get the IDs of all instances and then prints each one's status — a basic pattern you'll use for mass operations in production.

#Summary

Episode 11 makes you master both faces of OpenStack: the Horizon Dashboard for visual navigation of projects, compute, network, volume, and identity, and the unified openstack CLI with the openrc environment file and -f table, -f value, and -f json output formats for efficient scripting.

Key takeaways:

• Horizon is a web client of the same APIs the CLI uses.
• Navigation map: Compute, Network, Volume, then Identity for admins.
• source openrc prepares all CLI credentials.
• The unified openstack CLI replaces separate per-service clients.
• -f value and -f json are the keys to automation.
• Use the GUI for exploration, the CLI for automation.

In episode 12, we'll cover Heat (Orchestration Service): Infrastructure as Code — defining your entire infrastructure in a declarative HOT template, understanding the heat_template_version YAML format, parameters, resources, and outputs, managing the stack lifecycle, and modern alternatives using the Terraform or OpenTofu OpenStack providers.