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Jinja2 Filters

Peering Manager exposes functions and filters in additional to existing Jinja2 provided ones. These filters are used to parse, transform, fetch values of known types. If they are not used as expected, template processing may result in failure or half rendered texts.

safe_string

Converts a string to another one using only safe characters (retaining only ASCII characters). This string should be usable in a configuration without encoding issues.

Example:

description "Peering: AS{{ a_s.asn }} {{ a_s.name | safe_string }}"

tags

Returns an iterable structure for all tags assigned to an object.

Example:

Tags: {{ ixp | tags }}

has_tag / has_not_tag

Returns a boolean telling if a tag is or is not applied to an object.

Example:

{% if ixp | has_tag('remote-peering') %}
{% if ixp | has_not_tag('remote-peering') %}

ipv4 / ipv6

Given an argument, this filter will return a value that can be interpreted as true or false, for IPv4 or IPv6 respectively. If the value is indeed a valid IP that matches the filter use, a Python IP address object is returned, thus allowing getting field values (like version).

Example:

{% if session.ip_address | ipv6 %}

length / len / count

Determines the length/count of an object list, dictionary or SQL result.

Example:

{% if 10 == internet_exchanges | length %}

filter

Allows to pass a Django filter expression to allow filtering on a SQL result.

Examples:

{% for autonomous_system in autonomous_systems | filter(ipv6_max_prefixes__gt=100) %}
{% for session in bgpgroup | session | filter(router=router) %}

get

Allows to pass a Django filter expression to allow filtering on a SQL result and return a single object. If more than one object match the filter, this filter will behave in the exact same way as filter.

Example:

My AS is {{ affiliated_autonomous_systems | get(asn=64500) }}

iterate

Allows to select and to return the value of a single field for each object in a list. The field name must be passed as a string.

Example:

ASNs: {{ autonomous_systems | iterate('asn') }}

ixps

On an autonomous system, it will return all IXPs on which a local (affiliated) AS is peering with the remote AS. The second local_as parameter is mandatory to use this filter.

Example:

{% for ixp in autonomous_system | ixps(local_as) %}

shared_ixps

On an autonomous system, it will return all IXPs on which a local (affiliated) AS could peer with the remote AS. The second local_as parameter is mandatory to use this filter.

This filter is different from ixps as it will give back all IXPs the two AS are peering on in addition to the ones they do not peer on yet.

Example:

{% for ixp in autonomous_system | shared_ixps(local_as) %}

missing_sessions

On an autonomous system, it will return all sessions that can be configured between two autonomous systems. You must provide a second AS, providing an IXP is optional.

Example:

{% for missing in autonomous_system | missing_sessions(local_as) %}
IPv4: {{ missing.ipaddr4 }}
IPv6: {{ missing.ipaddr6 }}
{% endfor %}

prefix_list

Fetches all the prefixes of an autonomous system and returns them as a JSON formatted object. Prefixes are fetched using bgpq3 (or bgpq4) but can come from the local cache if present.

Example:

{% set prefixes = autonomous_system | prefix_list %}

connections

On an IXP or a router, it will return all connections attached to it.

Example:

{% for connection in router | connections %}
IPv4: {{ connections.ipv4_address }}
IPv6: {{ connections.ipv46_address }}
{% endfor %}

sessions / route_server

When using sessions on a BGP group or an IXP, peering sessions setup in the group or on the IXP will be returned as an iterable object. route_server works similarly but will only give back sessions setup with route servers on an IXP.

When used on an autonomous system, the sessions filter will return all BGP sessions setup with the AS (direct and IXP sessions).

Examples:

{% for session in ixp | sessions %}
{% for session in autonomous_system | sessions %}
{% for session in ixp | route_server(6) %}

local_ips

Applied on a session, the filter will fetch the local IP used to establish the session. If applied on an IXP or a BGP group, it will return IP addresses (v4 and v6) configured for the IXP/BGP group. In any other case, it will give back a null value.

Examples:

Local IPs: {{ session | local_ips }}
Local IPs: {{ ixp | local_ips }}

direct_sessions / ixp_sessions

When used on an autonomous system, it will return direct peering sessions or respectively IXP peering sessions setup with the AS. If 4 or 6 is passed as extra parameter, only the sessions with a IP version matching will be returned.

Examples:

{% for session in autonomous_system | direct_sessions %}
{% for session in autonomous_system | ixp_sessions(6) %}

ip_version

For a BGP session, it will return the IP version of the session given the IP address field.

Example:

{% if 6 == session | ip_version %}

max_prefix

For a BGP session, it will return the max prefix value corresponding to the remote AS and the IP address family.

Example:

unicast {
    prefix-limit {
        maximum {{ session | max_prefix }};
    }
}

cisco_password

From a valid Cisco type 7 password, returns the password stripping the magic word prefix.

Example:

{% if session.encrypted_password %}
password encrypted {{ session.encrypted_password | cisco_password }}
{% elif session.password %}
password clear {{ session.password }}
{% endif %}

direct_peers / ixp_peers

For a router, fetches all peers connected to it. When using direct_peers only peers with at least one direct peering session will be fetched while ixp_peers will fetch peers with at least on peering session setup on an IXP connected to the router.

Both filters can optionally take a slug value (as a string) to fetch sessions from a specific BGP group or IXP.

Example:

{% for session in router | ixp_peers %}
...
{% for session in router | direct_peers('transit') %}

iter_export_policies / iter_import_policies

Fetches routing policies applied on export or on import of an object. Note that these filters will not traverse relationships, therefore, they will not fetch AS policies for a session (for instance).

You can use a string as an option to these filters to select only a specific field of the policies.

Example:

export [ {{ session | iter_export_policies('slug') | join(' ') }} ];
import [ {{ session | iter_import_policies('slug') | join(' ') }} ];

merge_export_policies / merge_import_policies

Merges all import or export routing policies from an object into a single list. Policies are sorted based on their origin (AS/IXP/Session) and their weight.

Note that a IXP policy is less preferred than an AS policy. Session policies are the preferred ones. If a policy is referenced more than one time in the policy list, only the most preferred occurence will be kept.

The keyword (as a string) reverse can be used as option to these two filters to reverse the order of the list.

Example:

export [ {{ session | merge_export_policies | iterate('slug') | join(' ') }} ];
import [ {{ session | merge_import_policies('reverse') | iterate('slug') | join(' ') }} ];