[VrindaMarwah]

Description of the Solution

This PR adds support for human-readable custom hostnames (e.g., gpu-worker-01, login-server) alongside the standard nid format (nid001-nid999) when dns_enabled: true in orchestrator_config.yml. The system auto-detects the hostname format from the PXE mapping file and configures DHCP (CoreDHCP) and DNS (CoreDNS) accordingly, following the OpenCHAMI custom hostname management approach to keep DHCP, DNS, and cloud-init in agreement.

Related Issue

• Fixes [Feature request] Omnia Mono-repo Modularization #4849

Changes

Documentation (src/orchestrator/docs/)

• Updated input contract to document custom hostname validation rules
• Added comprehensive custom-hostnames.md with configuration examples, implementation details, and testing instructions

Configuration (src/orchestrator/input/orchestrator_config.yml)

• Updated dns_enabled comment to reflect support for both nid and custom hostname formats

Validation (src/orchestrator/plugins/module_utils/orchestrator_validation/)

• Updated hostname validation error message to indicate both formats are allowed
• Modified PXE mapping validator to accept any valid hostname when dns_enabled is true (removed strict nid pattern enforcement)

OpenCHAMI Deployment (src/orchestrator/roles/deploy_openchami/)

• Added PXE mapping file loading in ochami.yml and refresh_openchami_configs.yml
• Updated coredhcp.yaml.j2 template to add MAC-based hostname rules for custom hostnames before the general nid pattern
• Updated Corefile.j2 template to create separate DNS server blocks for custom hostnames using the hosts plugin

Files Changed

File	Change Type	Description
src/orchestrator/docs/contracts/input-contract.md	Modified	Updated HOSTNAME field description to include custom hostname support
src/orchestrator/docs/custom-hostnames.md	Added	Comprehensive documentation for custom hostname feature
src/orchestrator/input/orchestrator_config.yml	Modified	Updated dns_enabled configuration comments
src/orchestrator/plugins/module_utils/orchestrator_validation/messages/orchestrator_messages.py	Modified	Updated DNS hostname validation error me
ssage
src/orchestrator/plugins/module_utils/orchestrator_validation/validators/pxe_mapping_validator.py	Modified	Removed strict nid pattern enforcemen
t, allow any valid hostname
src/orchestrator/roles/deploy_openchami/tasks/configs/ochami.yml	Modified	Added PXE mapping file loading for custom hostname support
src/orchestrator/roles/deploy_openchami/tasks/refresh_openchami_configs.yml	Modified	Added PXE mapping file loading for config refresh
src/orchestrator/roles/deploy_openchami/templates/coredhcp/coredhcp.yaml.j2	Modified	Added MAC-based hostname rules for custom hostnames
src/orchestrator/roles/deploy_openchami/templates/coredns/Corefile.j2	Modified	Added separate DNS server blocks for custom hostnames

Testing

• Manual verification: Deployed cluster with custom hostnames in PXE mapping file, verify DHCP offers correct hostname via journalctl -u dhclient, query DNS with dig @<oim-ip> <hostname>.<domain> A +short, and confirm hostname is set on the node after cloud-init.

Backward Compatibility

• No breaking changes. The feature is backward compatible as it adds support for custom hostnames on top of existing, optional nid-hostname format.