[TRM] Add MPLS Label Mode Support in Terraform Module

[camschaecisco]

MPLS Label Mode Support

Add Terraform mapping logic to translate schema's MPLS label mode configurations into the Terraform provider's iosxe_mpls resource attributes.

Schema Mappings

Device MPLS Configuration:

• mpls.label_protocol → label_protocol
• mpls.label_mode_all_vrfs_protocol_all_afs_per_vrf → label_mode_all_vrfs_protocol_all_afs_per_vrf
• mpls.label_mode_all_vrfs_protocol_all_afs_per_prefix → label_mode_all_vrfs_protocol_all_afs_per_prefix
• mpls.label_mode_all_vrfs_protocol_all_afs_per_ce → label_mode_all_vrfs_protocol_all_afs_per_ce
• mpls.label_mode_all_vrfs_protocol_all_afs_vrf_conn_aggr → label_mode_all_vrfs_protocol_all_afs_vrf_conn_aggr
• mpls.label_mode_all_vrfs_protocol_bgp_vpnv4_per_vrf → label_mode_all_vrfs_protocol_bgp_vpnv4_per_vrf
• mpls.label_mode_all_vrfs_protocol_bgp_vpnv4_per_prefix → label_mode_all_vrfs_protocol_bgp_vpnv4_per_prefix
• mpls.label_mode_all_vrfs_protocol_bgp_vpnv4_per_ce → label_mode_all_vrfs_protocol_bgp_vpnv4_per_ce
• mpls.label_mode_all_vrfs_protocol_bgp_vpnv4_vrf_conn_aggr → label_mode_all_vrfs_protocol_bgp_vpnv4_vrf_conn_aggr
• mpls.label_mode_all_vrfs_protocol_bgp_vpnv6_per_vrf → label_mode_all_vrfs_protocol_bgp_vpnv6_per_vrf
• mpls.label_mode_all_vrfs_protocol_bgp_vpnv6_per_prefix → label_mode_all_vrfs_protocol_bgp_vpnv6_per_prefix
• mpls.label_mode_all_vrfs_protocol_bgp_vpnv6_per_ce → label_mode_all_vrfs_protocol_bgp_vpnv6_per_ce
• mpls.label_mode_all_vrfs_protocol_bgp_vpnv6_vrf_conn_aggr → label_mode_all_vrfs_protocol_bgp_vpnv6_vrf_conn_aggr

Changes

Add new MPLS resource module iosxe_mpls.tf:

• label_protocol (line 5) - MPLS label distribution protocol (ldp, tdp)
• label_mode_all_vrfs_protocol_all_afs_per_vrf (line 6) - Per-VRF label mode for all address families
• label_mode_all_vrfs_protocol_all_afs_per_prefix (line 7) - Per-prefix label mode for all address families
• label_mode_all_vrfs_protocol_all_afs_per_ce (line 8) - Per-CE label mode for all address families
• label_mode_all_vrfs_protocol_all_afs_vrf_conn_aggr (line 9) - VRF connected aggregate for all address families
• label_mode_all_vrfs_protocol_bgp_vpnv4_per_vrf (line 10) - Per-VRF label mode for BGP VPNv4
• label_mode_all_vrfs_protocol_bgp_vpnv4_per_prefix (line 11) - Per-prefix label mode for BGP VPNv4
• label_mode_all_vrfs_protocol_bgp_vpnv4_per_ce (line 12) - Per-CE label mode for BGP VPNv4
• label_mode_all_vrfs_protocol_bgp_vpnv4_vrf_conn_aggr (line 13) - VRF connected aggregate for BGP VPNv4
• label_mode_all_vrfs_protocol_bgp_vpnv6_per_vrf (line 14) - Per-VRF label mode for BGP VPNv6
• label_mode_all_vrfs_protocol_bgp_vpnv6_per_prefix (line 15) - Per-prefix label mode for BGP VPNv6
• label_mode_all_vrfs_protocol_bgp_vpnv6_per_ce (line 16) - Per-CE label mode for BGP VPNv6
• label_mode_all_vrfs_protocol_bgp_vpnv6_vrf_conn_aggr (line 17) - VRF connected aggregate for BGP VPNv6
• for_each (line 2) - Multi-device deployment support
• Support for device-specific, default, and null configuration values
• Three-tier fallback hierarchy: device config → global defaults → null
• Pre-commit hooks passed: terraform fmt, tflint, terraform-docs

This Enables Declarative Configuration of:

• MPLS label distribution protocol selection (LDP/TDP) for label-switched networks
• Per-device MPLS label mode policies with global default fallback
• Granular label allocation strategies across all address families (IPv4/IPv6 unicast/multicast)
• Address-family-specific label modes for BGP VPNv4 and VPNv6 deployments
• Per-VRF label allocation for label efficiency (single label per VRF)
• Per-prefix label allocation for traffic engineering and granular control
• Per-CE label allocation for customer edge differentiation
• VRF connected aggregate mode for optimized connected route label distribution
• Multi-device MPLS/VPN deployments from centralized YAML data models
• Network-wide MPLS label distribution behavior consistency
• Service provider MPLS VPN infrastructure provisioning
• Layer 3 VPN service deployment with flexible label allocation
• GitOps workflows for MPLS configuration management
• Carrier supporting carrier (CSC) and inter-AS VPN scenarios
• Label space optimization across large-scale MPLS networks

Version Requirements

IOS-XE 17.15 and later:

• ✅ label_protocol - MPLS label distribution protocol
• ✅ label_mode_all_vrfs_protocol_all_afs_per_vrf - Per-VRF mode for all AFs
• ✅ label_mode_all_vrfs_protocol_all_afs_per_prefix - Per-prefix mode for all AFs
• ✅ label_mode_all_vrfs_protocol_all_afs_per_ce - Per-CE mode for all AFs
• ✅ label_mode_all_vrfs_protocol_all_afs_vrf_conn_aggr - VRF connected aggregate for all AFs
• ✅ label_mode_all_vrfs_protocol_bgp_vpnv4_per_vrf - Per-VRF mode for BGP VPNv4
• ✅ label_mode_all_vrfs_protocol_bgp_vpnv4_per_prefix - Per-prefix mode for BGP VPNv4
• ✅ label_mode_all_vrfs_protocol_bgp_vpnv4_per_ce - Per-CE mode for BGP VPNv4
• ✅ label_mode_all_vrfs_protocol_bgp_vpnv4_vrf_conn_aggr - VRF connected aggregate for BGP VPNv4
• ✅ label_mode_all_vrfs_protocol_bgp_vpnv6_per_vrf - Per-VRF mode for BGP VPNv6
• ✅ label_mode_all_vrfs_protocol_bgp_vpnv6_per_prefix - Per-prefix mode for BGP VPNv6
• ✅ label_mode_all_vrfs_protocol_bgp_vpnv6_per_ce - Per-CE mode for BGP VPNv6
• ✅ label_mode_all_vrfs_protocol_bgp_vpnv6_vrf_conn_aggr - VRF connected aggregate for BGP VPNv6

Platform Notes:

• Both Cat8k routers and Cat9k switches support MPLS label mode features
• Label mode choices are mutually exclusive within each protocol/address-family scope
• YANG model contains implicit case nodes requiring element name duplication in provider
• Feature validated on IOS-XE 17.15.1

Example Configuration

Per-VRF Label Mode (Recommended for Label Efficiency):

iosxe:
  devices:
    - name: Cat8k-Router
      configuration:
        mpls:
          label_protocol: ldp
          label_mode_all_vrfs_protocol_all_afs_per_vrf: true

Per-Prefix Label Mode for Traffic Engineering:
iosxe:
  devices:
    - name: Cat9k-Switch
      configuration:
        mpls:
          label_protocol: ldp
          label_mode_all_vrfs_protocol_all_afs_per_prefix: true

BGP VPNv4-Specific Label Mode:
iosxe:
  devices:
    - name: PE-Router
      configuration:
        mpls:
          label_protocol: ldp
          label_mode_all_vrfs_protocol_bgp_vpnv4_per_vrf: true

Comprehensive Multi-AF Configuration:
iosxe:
  devices:
    - name: Core-Router
      configuration:
        mpls:
          label_protocol: ldp
          label_mode_all_vrfs_protocol_all_afs_per_vrf: true
          label_mode_all_vrfs_protocol_bgp_vpnv4_per_vrf: true
          label_mode_all_vrfs_protocol_bgp_vpnv6_per_vrf: true

Global Defaults:
iosxe:
  defaults:
    configuration:
      mpls:
        label_protocol: ldp
        label_mode_all_vrfs_protocol_all_afs_per_vrf: true

Testing

Multi-Platform Validation
- ✅ Catalyst 8000V (Router, IOS-XE 17.15): MPLS deployed successfully
  - LDP protocol with per-VRF label mode for all address families
- ✅ Catalyst 9000 (Switch, IOS-XE 17.15): MPLS deployed successfully
  - LDP protocol with per-prefix label mode for all address families

Terraform Operations Verified
- ✅ terraform plan - Correctly identifies MPLS configuration changes
- ✅ terraform apply - Successfully creates MPLS configuration
- ✅ terraform destroy - Cleanly removes MPLS configuration
- ✅ Device verification - All MPLS settings present in running-config
- ✅ State management - Proper resource state tracking across lifecycle
- ✅ Idempotency - No changes on second apply
- ✅ Multi-device deployment - Tested with both router and switch simultaneously

Robot Framework Integration Tests
- ✅ Router tests passed (1/1) - Per-VRF mode validated via RESTCONF
- ✅ Switch tests passed (1/1) - Per-prefix mode validated via RESTCONF
- ✅ RESTCONF validation - JSONPath queries validate all 13 parameters
- ✅ Schema validation - nac-validate passes for all test data
- ✅ Overall result: 2 tests, 2 passed, 0 failed, 0 skipped

Pre-commit Quality Checks
- ✅ Terraform fmt............................................................Passed
- ✅ Terraform validate with tflint...........................................Passed
- ✅ terraform-docs...........................................................Passed
- ✅ terraform-docs...........................................................Passed
- ✅ terraform-docs...........................................................Passed
- ✅ terraform-docs...........................................................Passed