ServicesTemplate Rendering Service

Jinja2 filter quick reference

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Quick lookup for common filters used in network templates. For the bundled provider’s exact object and configuration-context sources, see Nautobot render data mapping.

Device information

{{ device_data|hostname }}                    {# Device hostname #}
{{ device_data|site_name }}                   {# Site name #}
{{ device_data|platform }}                    {# Platform (e.g., "Cumulus Linux") #}
{{ device_data|role }}                        {# Device role (e.g., "TAN-Leaf") #}
{{ device_data|model }}                       {# Device model #}
{{ device_data|desired_firmware }}            {# Target firmware version #}
{{ device_data|uuid }}                        {# Provider device identifier #}
{{ device_data|device_tags }}                 {# List of device tags #}
{{ device_data|has_tag("tag-name") }}         {# Check for specific tag #}

Routing and BGP

{{ device_data|router_id }}                   {# Router ID (loopback IP without mask) #}
{{ device_data|asn }}                         {# BGP ASN for default VRF #}
{{ device_data|asn("VRF-NAME") }}             {# BGP ASN for specific VRF #}
{% set bgp = device_data|bgp_routing_instance %}
{% for peer in bgp.peers %}
  neighbor {{ peer.peer_ipv4 }} remote-as {{ peer.asn }}
  neighbor {{ peer.peer_ipv4 }} description {{ peer.description }}
  neighbor {{ peer.peer_ipv4 }} peer-group {{ peer.peer_group }}
{% endfor %}
{{ "1.100"|asplain }}                         {# Convert ASDOT to ASPLAIN (→ 65636) #}

Interface operations

{# Get all interfaces #}
{% for intf in device_data|interfaces %}
  {{ intf.name }} - {{ intf.description }}
{% endfor %}
{# Filter by prefix #}
{% for intf in device_data|interfaces(prefix="swp") %}
  interface {{ intf.name }}
{% endfor %}
{# Filter by role #}
{% for intf in device_data|interfaces(role="Uplink") %}
  interface {{ intf.name }}
{% endfor %}
{# Filter by tags #}
{% for intf in device_data|interfaces(tags=["qos-enabled"]) %}
  interface {{ intf.name }}
{% endfor %}
{# Get specific interface #}
{% set intf = device_data|interface_by_name("eth0") %}
{{ intf.name }} - {{ intf.primary_ipv4 }}
{# Get breakout count #}
{{ device_data|breakout_count("swp1") }}      {# Returns 0, 2, 4, or 8 #}
{# Loopback parent prefix #}
{{ device_data|loopback_prefix }}             {# Parent prefix of loopback IP #}

Interface object properties

{{ intf.name }}                               {# Interface name #}
{{ intf.description }}                        {# Description #}
{{ intf.primary_ipv4 }}                       {# Primary IPv4 (with prefix) #}
{{ intf.primary_ipv6 }}                       {# Primary IPv6 (with prefix) #}
{{ intf.enabled }}                            {# Admin state (true/false) #}
{{ intf.mtu }}                                {# MTU #}
{{ intf.vrf }}                                {# VRF name (default if none) #}
{{ intf.role }}                               {# Interface role #}
{{ intf.untagged_vlan }}                      {# Untagged VLAN ID (or None) #}
{{ intf.tagged_vlans }}                       {# List of tagged VLAN IDs #}
{{ intf.tags }}                               {# List of interface tags #}
{{ intf.has_bgp_peer() }}                     {# True if BGP-eligible #}
{# Connected device info #}
{% if intf.connected_interface %}
  {{ intf.connected_interface.name }}
  {{ intf.connected_interface.device.name }}
  {{ intf.connected_interface.device.role }}
  {{ intf.connected_interface.device.asn }}
  {{ intf.connected_interface.device.peer_ipv4 }}
{% endif %}

IP address manipulation

{{ "10.0.0.5/24"|gateway }}                   {# → "10.0.0.1" (first usable) #}
{{ "10.0.0.5/31"|get_peer_ip }}               {# → peer in /31 #}
{{ "10.0.0.5/24"|network_address }}           {# → "10.0.0.0/24" #}
{# Subnet operations #}
{% for subnet in "10.0.0.0/16"|subnet(24) %}
  {{ subnet }}                                {# /24 subnets #}
{% endfor %}
{{ "10.0.0.0/24"|supernet(16) }}              {# → "10.0.0.0/16" #}
{# All IPs in range #}
{% for ip in "10.0.0.0/29"|ips %}
  {{ ip }}                                    {# Each IP in subnet #}
{% endfor %}
{# Netmask notation #}
{% set addr, mask = "10.0.0.0/24"|netmask_notation %}
{{ addr }}                                    {# → "10.0.0.0" #}
{{ mask }}                                    {# → "255.255.255.0" #}
{# DHCP host range #}
{% set first, last = "10.0.0.0/24"|host_range %}
range {{ first }} {{ last }};                 {# → range 10.0.0.2 10.0.0.254 #}
{# RFC3442 static route for DHCP #}
{{ "10.1.0.0/16"|rfc3442_classless_static_route("10.0.0.1") }}

Location and site data

{{ location_data.routing.site_asn }}          {# Site BGP ASN #}
{% for prefix in location_data|site_aggregates("Aggregate") %}
  network {{ prefix }}
{% endfor %}
{% for prefix in location_data|site_aggregates("Aggregate", tags=["bgp-advertise"]) %}
  network {{ prefix }}
{% endfor %}
{% for prefix in location_data|site_aggregates("Infrastructure", exclude_tags=["do-not-advertise"]) %}
  network {{ prefix }}
{% endfor %}
{% for rs in location_data.topology.route_servers %}
{% for address in rs.loopback_addresses %}
  neighbor {{ address }} remote-as {{ rs.routing_asn }}
{% endfor %}
{% endfor %}
{% for router in location_data.topology.wan_routers %}
  router {{ router.name }} loopbacks {{ router.loopback_addresses|join(",") }}
{% endfor %}
{% for prefix in location_data.address_space.uc_jumphost_prefixes %}
  ip prefix-list JUMPHOSTS permit {{ prefix }}
{% endfor %}

DHCP helper addresses

{# By VLAN: { vlan_id: [helpers] } for device VLANs #}
{% set vlan_helpers = device_data|helper_addresses_by_vlan(location_data) %}
{% for vlan_id, helpers in vlan_helpers.items() %}
  vlan {{ vlan_id }}:
  {% for helper in helpers %}
    dhcp-server {{ helper }}
  {% endfor %}
{% endfor %}
{# By VRF: { vrf_name: { vlans: [], helpers: [] } } #}
{% set vrf_configs = device_data|helper_addresses_by_vrf(location_data) %}
{% for vrf_name, config in vrf_configs.items() %}
  vrf {{ vrf_name }}:
    vlans: {{ config.vlans }}
  {% for helper in config.helpers %}
    dhcp-server {{ helper }}
  {% endfor %}
{% endfor %}

Secret management

{% set secret = "secret_key"|load_secret(site=device_data|site_name) %}
{% set secret = "secret_key"|load_secret(region="US-WEST") %}
{% for user in device_data|users %}
  {# user.username, user.role (optional), user.password_key #}
  {% set password = user.password_key|load_secret(site=device_data|site_name) %}
  username {{ user.username }} secret {{ password|encrypt("sha512", site=device_data|site_name) }}{% if user.role %} role {{ user.role }}{% endif %}
{% endfor %}
{% set password = "root_password_r1"|load_secret(site=device_data|site_name) %}
username admin secret {{ password|encrypt("sha512", site=device_data|site_name) }}
tacacs-server key {{ ("tacacs_key_r1"|load_secret(site=device_data|site_name))|encrypt("ciscot7", site=device_data|site_name) }}

In development or testing, set NV_CONFIG_MANAGER_SKIP_VAULT=1 to use dummy secret values.

ISIS

{{ device_data|router_id|isis_system_id }}

VRF operations

{% for vrf in device_data|attached_vrfs %}
  vrf {{ vrf.name }}
    vni {{ vrf.vni }}
    {% for rt in vrf.export_targets %}
    route-target export {{ rt }}
    {% endfor %}
    {% for rt in vrf.import_targets %}
    route-target import {{ rt }}
    {% endfor %}
{% endfor %}

Specialized filters

{% for entry in device_data|spx_subnets(ip_version=4) %}
  route {{ entry.subnet }} via {{ entry.rail_prefix }}
{% endfor %}
{% for port in device_data|console_server_ports %}
  console-port {{ port.name }} connects to {{ port.device.name }}
{% endfor %}

Common patterns

Management interface

{% set mgmt = device_data|interface_by_name("eth0") %}
interface eth0
  description {{ mgmt.description }}
  ip address {{ mgmt.primary_ipv4 }}
  ip gateway {{ mgmt.primary_ipv4|gateway }}
  vrf mgmt

Conditional configuration

{% if device_data|has_tag("enable-feature") %}
feature-x enable
{% endif %}

Error handling

Most filters raise FilterException when data is missing. Use fail_if_missing=False on interface_by_name to get None instead:

{% set intf = device_data|interface_by_name("eth1", fail_if_missing=False) %}
{% if intf %}
  {# configure interface #}
{% endif %}

Further reading

For detailed explanations, examples, and Nautobot field mappings, see Network Template Rendering System.