User Guides: OpenStack Client

This section provides command-line instructions for common tasks using the openstack CLI.

Prerequisite: Ensure you have installed and configured the OpenStack Client.

Managing Compute (Nova)

Launching an Instance

1. List Available Resources (Flavors, Images, Volumes, Networks, etc.):

openstack flavor list
openstack image list
openstack volume list
openstack volume type list
openstack volume snapshot list
openstack network list
openstack subnet list
openstack security group list
openstack floating ip list
openstack keypair list

2. Create the Server:

openstack server create --image <IMAGE_ID> \
                        --flavor <FLAVOR_ID> \
                        --network <NETWORK_ID> \
                        --key-name <KEYPAIR_NAME> \
                        --security-group <SECURITY_GROUP_NAME> \
                        my-instance

Resizing an Instance

1. Resize the Server:

openstack server resize --flavor <NEW_FLAVOR_ID> --wait <SERVER_ID>

2. Confirm the Resize:

openstack server resize confirm <SERVER_ID>

Migrating Instances

Live Migration: Move a running instance to another host without downtime.

openstack server migrate --live-migration [--host <HYPERVISOR_HOSTNAME>] --wait <INSTANCE_UUID>

Cold Migration: Move a stopped instance (or pause it during move) to another host.

openstack server migrate --wait <INSTANCE_UUID>

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Managing Flavors

Creating Flavors

Note: creating flavors usually requires admin privileges.

openstack flavor create --id <ID> --vcpus <VCPUS> --ram <RAM> --disk <DISK> <FLAVOR_NAME>

Performance Tuning (Pinning & Hugepages)

For high-performance workloads, you can configure flavors with dedicated CPU policies and hugepages.

Properties for Dedicated Performance:

Property	Value	Description
hw:cpu_policy	dedicated	Dedicate physical cores to vCPUs.
hw:cpu_thread_policy	isolate	Do not share physical cores with other processes.
hw:mem_page_size	2048	Use 2MB hugepages (requires trait).
hw:vif_multiqueue_enabled	true	Enable multiqueue for network interfaces.
hw:vif_multiqueue_max	4	Max queues.
hw_rng:allowed	true	Allow Random Number Generator.
trait:CUSTOM_HUGEPAGES_2048K	required	Schedule only on hosts with hugepages enabled.

Example: Creating a Performance Flavor

# 1. Create the base flavor
openstack flavor create --vcpus 4 --ram 8192 --disk 50 perf.m1.large

# 2. Set the performance properties
openstack flavor set --property hw:cpu_policy='dedicated' \
                     --property hw:cpu_thread_policy='isolate' \
                     --property hw:mem_page_size='2048' \
                     --property hw:vif_multiqueue_enabled='true' \
                     --property hw:vif_multiqueue_max='4' \
                     --property hw_rng:allowed='true' \
                     --property trait:CUSTOM_HUGEPAGES_2048K='required' \
                     perf.m1.large

Hugepages Requirement

If using hugepages (hw:mem_page_size='2048'), you must ensure the trait trait:CUSTOM_HUGEPAGES_2048K='required' is set. Please contact the Tier5 support team to ensure your cloud environment supports hugepages and these traits.

---

Managing Images (Glance)

List Images:

openstack image list

Create Image:

openstack image create --file <IMAGE-NAME>.raw \
                       --disk-format raw \
                       --container-format bare \
                       --public \
                       --property os_distro='ubuntu' \
                       --property os_admin_user='ubuntu' \
                       --property os_version='24.04' \
                       <IMAGE-NAME>

Metadata Properties (--property):

Setting correct metadata is crucial for a good user experience in the dashboard:

• os_distro: Determines the icon displayed in Horizon/Skyline (e.g., ubuntu, centos, windows).
• os_admin_user: Hints the default SSH username to the user in the dashboard instance details.
• os_version: Specifies the operating system version.

For a full list of recognized properties, refer to the OpenStack Useful Image Properties documentation.

---

Managing Key Pairs

Create Key Pair:

openstack keypair create my-key > my-key.pem
chmod 600 my-key.pem

List Key Pairs:

openstack keypair list

---

Networking (Neutron)

Network Visualization

The CLI lists networks and subnets but does not provide a topology graph.

openstack network list
openstack subnet list

Creating a Private Network

# Create Network
openstack network create my-network

# Create Subnet
openstack subnet create --network my-network \
                        --subnet-range 192.168.10.0/24 \
                        --dns-nameserver 8.8.8.8 \
                        my-subnet

Configuring Security Groups

# Create Security Group
openstack security group create my-secgroup

# Add Rules (SSH and HTTP)
openstack security group rule create --protocol tcp --dst-port 22:22 --remote-ip 0.0.0.0/0 my-secgroup
openstack security group rule create --protocol tcp --dst-port 80:80 --remote-ip 0.0.0.0/0 my-secgroup

---

Load Balancing (Octavia)

# 1. Create Load Balancer
openstack loadbalancer create --name my-lb --vip-subnet-id <SUBNET_ID>

# 2. Create Listener
openstack loadbalancer listener create --name my-listener --protocol HTTP --protocol-port 80 my-lb

# 3. Create Pool
openstack loadbalancer pool create --name my-pool --lb-algorithm ROUND_ROBIN --listener my-listener --protocol HTTP

# 4. Add Members (Instances)
openstack loadbalancer member create --subnet-id <SUBNET_ID> --address <INSTANCE_IP> --protocol-port 80 my-pool

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Kubernetes Clusters (Magnum)

Advanced Workloads: Kata Containers

For workloads requiring stronger isolation, you can use Kata Containers with your Magnum clusters. See the Kata Containers Guide.

# List Templates
openstack coe cluster template list

# Create Cluster
openstack coe cluster create --cluster-template <TEMPLATE_ID> \
                             --master-count 1 \
                             --node-count 2 \
                             --keypair <KEYPAIR_NAME> \
                             my-cluster

# Retrieve Kubeconfig
openstack coe cluster config my-cluster > kubeconfig

### Cluster Upgrade

Upgrading a cluster involves updating the Kubernetes version and/or the operating system of the nodes. This is done by creating a new cluster template with the desired versions and then applying it to the existing cluster.

!!! warning "Rolling Upgrade & Workload Compatibility"
    *   **Rolling Update**: The upgrade process performs a rolling update, replacing nodes one by one. This preserves cluster availability but may take time.
    *   **API Compatibility**: Upgrading the Kubernetes version (e.g., v1.29 to v1.30) **does NOT** automatically update your deployments or statefulsets. You must ensure your workloads are compatible with the new Kubernetes API version **before** upgrading.
    *   **Backup**: It is highly recommended to backup your cluster data (etcd, PVs) before upgrading.

```bash
# 1. Create a new Cluster Template (e.g., for a newer K8s version)
# (See 'openstack coe cluster template create' or use the dashboard)

# 2. Trigger the Upgrade
openstack coe cluster upgrade my-cluster <NEW_TEMPLATE_ID>

Cluster Scale/Resize

You can increase or decrease the number of worker nodes in your cluster.

# Resize the cluster to a specific number of worker nodes
openstack coe cluster resize my-cluster <NEW_NODE_COUNT>

Scaling Behavior

• Scaling Up: Adds new worker nodes to the cluster.
• Scaling Down: Removes worker nodes. Magnum attempts to drain nodes before removal, but ensure your workloads can tolerate node failures.
• Control Plane: You generally cannot resize the control plane (master nodes) after creation.

---

## Storage (Cinder)

### Managing Volumes

```bash
# Create Volume
openstack volume create --size 10 my-volume

# Attach to Instance
openstack server add volume <INSTANCE_ID> my-volume

Volume Snapshots

openstack volume snapshot create --volume <VOLUME_ID> my-snapshot

Volume Backups

openstack volume backup create --name my-backup <VOLUME_ID>

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Orchestration (Heat)

Stacks

# Create Stack from Template
openstack stack create -t my-template.yaml my-stack

# List Stacks
openstack stack list