Task 03: Configure Cluster Mode

DOCUMENT CATEGORY: Task SCOPE: Cluster mode configuration PURPOSE: Define cluster VPN, Key Vault, storage, and DNS records

Status: Active Last Updated: 2026-02-07

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Objective

Configure cluster-specific resources including VPN connection to on-premises cluster network, cluster Key Vault, storage account, and DNS A records for cluster nodes.

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Prerequisites

• Task 01 completed (core variables)
• Task 02 completed (management mode, VPN Gateway deployed)
• Cluster network details from on-premises team
• Cluster node hostnames and IP addresses
• Physical cluster location code (3 chars max)

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Configuration

Cluster Identification

cluster_instance = "c01" # Cluster instance number (c01, c02, etc.)
cluster_location = "ral" # Physical location code (3 chars: ral, phx, dal)

Cluster Network Configuration

cluster_network_config = {
 on_prem = {
 asn = 64512 # On-premises cluster BGP ASN
 cluster_ip = "10.100.3.120" # First cluster node IP
 gateway_public_ip = "203.0.113.100" # On-prem gateway public IP or FQDN
 gateway_bgp_ip = "169.254.21.1" # On-prem gateway BGP IP
 }
 
 azure = {
 vpn_gateway_id = module.management.vpn_gateway.id # Reference to management VPN Gateway
 deploy_arc_gateway = false # Deploy Azure Arc Gateway (optional)
 }
}

Cluster Nodes

nodes = {
 "c01-n01-prd-ral" = "10.100.3.101" # Node 1 hostname and IP
 "c01-n02-prd-ral" = "10.100.3.102" # Node 2 hostname and IP
 "c01-n03-prd-ral" = "10.100.3.103" # Node 3 hostname and IP
 "c01-n04-prd-ral" = "10.100.3.104" # Node 4 hostname and IP (optional)
}

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Variable Reference

Variable	Type	Description	Example
cluster_instance	string	Cluster instance identifier	"c01"
cluster_location	string	Physical location (3 chars)	"ral", "phx"
on_prem.asn	number	On-prem cluster BGP ASN	64512
on_prem.cluster_ip	string	First cluster node IP	"10.100.3.120"
on_prem.gateway_public_ip	string	Gateway public IP/FQDN	"203.0.113.100"
on_prem.gateway_bgp_ip	string	Gateway BGP IP	"169.254.21.1"
azure.vpn_gateway_id	string	VPN Gateway resource ID	module.management...
azure.deploy_arc_gateway	bool	Deploy Arc Gateway	false
nodes	map(string)	Node hostname to IP mapping	{ "c01-n01..." = "10..." }

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Node Naming Convention

Cluster node hostnames should follow this pattern:

{cluster}-{node}-{env}-{location}

Examples:
 c01-n01-prd-ral # Cluster 01, Node 01, Production, Raleigh
 c01-n02-prd-ral # Cluster 01, Node 02, Production, Raleigh
 c02-n01-dev-phx # Cluster 02, Node 01, Development, Phoenix

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Azure Arc Gateway

Set deploy_arc_gateway = true if you need:

• Azure Arc-enabled services integration
• Hybrid cloud management capabilities
• Azure Policy enforcement on-premises

Default

Most deployments use deploy_arc_gateway = false. Enable only if specifically required.

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Complete Example

# terraform.tfvars (cluster mode section)

# Cluster Identification
cluster_instance = "c01"
cluster_location = "ral"

# Cluster Network
cluster_network_config = {
 on_prem = {
 asn = 64512
 cluster_ip = "10.100.3.120"
 gateway_public_ip = "203.0.113.100"
 gateway_bgp_ip = "169.254.21.1"
 }
 
 azure = {
 vpn_gateway_id = module.management.vpn_gateway.id
 deploy_arc_gateway = false
 }
}

# Cluster Nodes (4-node cluster)
nodes = {
 "c01-n01-prd-ral" = "10.100.3.101"
 "c01-n02-prd-ral" = "10.100.3.102"
 "c01-n03-prd-ral" = "10.100.3.103"
 "c01-n04-prd-ral" = "10.100.3.104"
}

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Validation

• Cluster instance and location codes correct
• On-premises cluster BGP ASN matches network team documentation
• Cluster IP and gateway public IP verified
• Gateway BGP IP confirmed with network team
• VPN Gateway ID references management deployment
• All cluster nodes listed with correct hostnames and IPs
• Node naming convention follows standard pattern
• Arc Gateway setting matches requirements

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Resources Deployed

When cluster mode is configured, these resources are created:

Resource	Purpose
VPN Connection	Site-to-site connectivity to cluster network
Key Vault	Cluster-specific secrets storage
Log Analytics Workspace	Cluster monitoring and logs
Storage Account	Cloud witness for cluster quorum
DNS A Records	Name resolution for all cluster nodes
Arc Gateway (optional)	Hybrid cloud management

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Next Steps

Configuration complete. Proceed to Phase 02 - Pipeline Execution to deploy infrastructure.

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Navigation

Previous	Up	Next
Task 02 - Management Mode	Phase 01 - Configuration	Phase 02 - Pipeline Execution

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Version Control

Version	Date	Author	Changes
1.0.0	2026-03-24	Azure Local Cloudnology Team	Initial release