bug: Jinja computed attribute failure if related node is not found

[BeArchiTek]

Component

API Server / GraphQL

Infrahub version

1.1.6

Current Behavior

When a computed_attribute (in jinja2) is using an optional related node, and this is one is not set, the API reply with a cryptic "Unable to find the peer"

The schema used for this :

  - name: BGPPeerGroup
    namespace: Routing
    menu_placement: RoutingBGPSession
    uniqueness_constraints:
      - ["name__value"]
    human_friendly_id:
      - name__value
    order_by:
      - name__value
    display_labels:
      - description__value
    attributes:
      - name: name
        kind: Text
        optional: false
        order_weight: 1000
      - name: description
        kind: Text
        computed_attribute:
          kind: Jinja2
          jinja2_template: "{% if remote_as__asn__value %}.{{ remote_as__asn__value }}{% endif %}.{{ address_family__value }}"
        read_only: true
        order_weight: 1100
      - name: address_family
        kind: Dropdown
        choices:
          - name: "ipv4"
            label: IPv4
            description: "Policy applies to IPv4 addresses."
            color: "#E6E6FA"  # lavender
          - name: "ipv6"
            label: IPv6
            description: "Policy applies to IPv6 addresses."
            color: "#E6E6FA"  # lavender
        default_value: "ipv4"
        order_weight: 1150
    relationships:
      - name: local_as
        identifier: bgppeergroup__local_as
        peer: RoutingAutonomousSystem
        optional: true
        cardinality: one
        kind: Attribute
      - name: remote_as
        identifier: bgppeergroup__remote_as
        peer: RoutingAutonomousSystem
        optional: true
        cardinality: one
        kind: Attribute

Expected Behavior

The API should provide a better error for the non-creation of the node.

Steps to Reproduce

1- load the schema above in infrahub as well as this one :

  - name: AutonomousSystem
    namespace: Routing
    uniqueness_constraints:
      - ["asn__value"]
    human_friendly_id:
      - "asn__value"
    order_by:
      - asn__value
    display_labels:
      - asn__value
    attributes:
      - name: name
        kind: Text
        computed_attribute:
          kind: Jinja2
          jinja2_template: "AS{{ asn__value }}"
        read_only: true
        description: "Name of the Autonomous System"
        order_weight: 1000
      - name: asn
        kind: Number
        description: "Autonomous System Number"
        order_weight: 1050

3 - try creating a RoutingBGPPeerGroup without any remote_as

Additional Information

A better if/else test seems to be

jinja2_template: "{% if remote_as__asn__value is defined and remote_as__asn__value %}.{{ remote_as__asn__value }}{% endif %}.{{ address_family__value }}"

But I find strange we can't directly use the relationship name like : if remote_as

[ogenstad]

The error would come from the fact that the attribute is marked as mandatory. It could of course return a more user friendly error, but based on the above it seems like you actually want it to return a blank string or undefined value for situations like this?

[BeArchiTek]

The compute_attribute is mandatory but notremote_as, I would then expect to only have the existing piece which would be the address_family_value

[ogenstad]

What about if it looks like this:

jinja2_template: "{{ remote_as__asn__value }}"

Would you say that this should result in an error or an empty string?

[BeArchiTek]

I would expect an error if there is not default_value. For example something like

jinja2_template: "{{ remote_as__asn__value | default_value("XXX") }}"

But then we could use default_value(omitted) which would result in an empty string I guess 🤔

[ogenstad]

I was thinking along the same lines.