Inventory Structure

Inventory Structure¶

Learn how to organize your AVD inventory for optimal workflow with AVD CLI.

Standard Structure¶

AVD CLI supports standard Ansible inventory structures with AVD group_vars and host_vars:

inventory/
├── inventory.yml           # Main inventory file (hosts and groups)
├── group_vars/            # Group-level variables
│   ├── all.yml           # Global variables (inherited by all devices)
│   ├── all/              # Alternative: directory for multiple files
│   │   └── common.yml
│   ├── FABRIC.yml        # Fabric-level variables
│   ├── SPINES.yml        # Spine-specific variables
│   ├── LEAFS.yml         # Leaf-specific variables
│   └── campus_leaves/    # Group directory with multiple files
│       ├── interfaces.yml
│       ├── dot1x.yml
│       └── leaf.yml
└── host_vars/             # Host-level variables (optional)
    ├── spine1.yml        # Individual host configuration
    └── leaf1.yml

Inventory File Structure¶

The main inventory.yml file defines the hierarchy of devices and groups:

EOS Design Workflow Example¶

---
all:
  children:
    cv_servers:           # CloudVision servers (optional)
      hosts:
        cv_atd1:
          ansible_host: 192.168.0.5
          cv_collection: v3
    ATD_LAB:              # Main lab group
      children:
        ATD_FABRIC:       # Fabric group containing spines and leafs
          children:
            ATD_SPINES:   # Spine switches group
              vars:
                type: spine
              hosts:
                s1-spine1:
                  ansible_host: 192.168.0.10
                s1-spine2:
                  ansible_host: 192.168.0.11
            ATD_LEAFS:    # Leaf switches group
              vars:
                type: l3leaf
              children:
                pod1:     # Leaf sub-groups for MLAG pairs
                  hosts:
                    s1-leaf1:
                      ansible_host: 192.168.0.12
                    s1-leaf2:
                      ansible_host: 192.168.0.13
                pod2:
                  hosts:
                    s1-leaf3:
                      ansible_host: 192.168.0.14
                    s1-leaf4:
                      ansible_host: 192.168.0.15
        ATD_TENANTS_NETWORKS: # Tenant configuration group
          children:
            ATD_LEAFS:
        ATD_SERVERS:         # Server configuration group
          children:
            ATD_LEAFS:
  vars:
    # Global Ansible connection parameters
    ansible_user: arista
    ansible_password: arista123!
    ansible_network_os: arista.eos.eos
    ansible_connection: httpapi
    ansible_httpapi_use_ssl: true
    ansible_httpapi_validate_certs: false
    ansible_python_interpreter: $(which python3)

CLI Config Gen Workflow Example¶

For configuration-only generation without topology design:

---
all:
  hosts:
    spine1:
      ansible_host: 192.168.73.11
    spine2:
      ansible_host: 192.168.73.12
    leaf1:
      ansible_host: 192.168.73.13
    leaf2:
      ansible_host: 192.168.73.14
  vars:
    ansible_user: admin
    ansible_connection: httpapi
    ansible_network_os: arista.eos.eos
    ansible_httpapi_use_ssl: true
    ansible_httpapi_validate_certs: false

Variable Inheritance Hierarchy¶

Variables are inherited in this specific order (last wins):

group_vars/all.yml - Global defaults for all devices
Parent group variables - Higher-level groups (e.g., ATD_LAB.yml)
Fabric group variables - Fabric-specific settings (e.g., ATD_FABRIC.yml)
Device type groups - Role-specific variables (e.g., ATD_SPINES.yml, ATD_LEAFS.yml)
Sub-group variables - Pod or rack-specific settings (e.g., pod1.yml)
Host-specific variables - Individual device overrides from host_vars/

Example Inheritance Flow¶

For device s1-leaf1 in the hierarchy above:

all.yml → ATD_LAB.yml → ATD_FABRIC.yml → ATD_LEAFS.yml → pod1.yml → host_vars/s1-leaf1.yml

Group Variable Organization¶

Single File per Group¶

group_vars/
├── all.yml              # Global settings
├── ATD_FABRIC.yml       # Fabric topology and BGP settings
├── ATD_SPINES.yml       # Spine-specific configuration
└── ATD_LEAFS.yml        # Leaf-specific configuration

Directory Structure per Group¶

group_vars/
├── all/
│   ├── common.yml       # Base settings
│   └── credentials.yml  # Authentication settings
├── campus_leaves/
│   ├── interfaces.yml   # Interface profiles and network ports
│   ├── dot1x.yml       # 802.1X authentication settings
│   └── leaf.yml        # Leaf-specific topology
└── campus_spines/
    └── spines.yml       # Spine configuration

Jinja2 Template Support¶

AVD CLI supports Jinja2 templating in all variable files, enabling dynamic configuration based on conditions and variables.

Basic Jinja2 Examples¶

Conditional Values¶

# Platform-dependent MTU settings
default_interface_mtu: "{% if lab_type == 'act' %}1500{% else %}{{poc_platform_mtu}}{% endif %}"
mlag_peer_link_mtu: "{% if lab_type == 'act' %}1500{% else %}9214{% endif %}"

# Environment-based VRFs
mgmt_interface_vrf: "{{default_poc_management_vrf}}"
default_poc_syslog_vrf: "{{ default_poc_management_vrf }}"

Variable References¶

# Reference other variables
default_poc_management_vrf: MGMT
default_poc_syslog_server: "192.168.0.201"
default_poc_sflow_vrf: "{{ default_poc_management_vrf }}"
default_poc_radius_vrf: "{{ default_poc_management_vrf }}"

Complex Logic¶

# Feature flags with conditions
lab_type: "act"
has_poe: False
has_storm_control: False

# Dynamic platform settings
poc_platform_mtu: 1500
platform_settings:
  mtu: "{% if lab_type == 'act' %}1500{% else %}{{poc_platform_mtu}}{% endif %}"
  features:
    poe: "{{ has_poe }}"
    storm_control: "{{ has_storm_control }}"

Advanced Jinja2 Usage¶

Switch-Specific Configuration¶

network_ports:
  - switches:
      - "leaf-1a"
      - "leaf-1b"
      - "leaf-2a"
    switch_ports:
      - Ethernet10-15
    description: 802.1x Standard Port - EAPoL with Multi Host
    profile: PP-DOT1X
    native_vlan: 666
    structured_config:
      switchport:
        phone:
          trunk: untagged
          vlan: 667

  - platforms:           # Platform-based selection
      - '720XP'
    switch_ports:
      - Ethernet1-10
    description: 802.1x Standard Port - EAPoL with Multi Host
    profile: PP-DOT1X
    native_vlan: 666

Custom Structured Configuration¶

# Prefix for custom configuration sections
custom_structured_configuration_prefix:
  - "custom_inband_"
  - "custom_structured_"

# Dynamic fabric tags
default_cv_tags_campus: CAMPUS_AVD
cv_tags:
  - "{{ default_cv_tags_campus }}"
  - "FABRIC_{{ fabric_name | upper }}"

Best Practices¶

1. Group Organization¶

Use hierarchical groups that reflect your network topology
Separate fabric configuration from tenant/service configuration
Group devices by role (spine, leaf, border-leaf, etc.)

2. Variable Structure¶

Keep global settings in group_vars/all.yml
Use fabric-specific files for topology and underlay settings
Separate tenant/service configuration into dedicated groups

3. Jinja2 Usage¶

Use Jinja2 for environment-specific values (lab vs production)
Reference variables to avoid duplication
Keep complex logic in dedicated variable files

4. File Organization¶

Use single files for simple groups
Use directories for complex groups with multiple configuration aspects
Name files descriptively (e.g., interfaces.yml, routing.yml)

5. Host Variables¶

Use host_vars/ sparingly for device-specific overrides
Prefer group variables for consistent configuration
Document any host-specific exceptions

Validation¶

AVD CLI automatically validates your inventory structure:

# Validate inventory structure
avd-cli info --inventory ./inventory

# Check variable inheritance
avd-cli info --inventory ./inventory --format yaml

See the complete User Guide for more commands and options.