Generator Manager

The Generator Manager produces Python generators that query Infrahub for design objects and automatically create or update the infrastructure objects derived from them. Generators are idempotent: re-running them updates existing objects rather than creating duplicates. The skill generates the Python class, GraphQL query, and .infrahub.yml registration.

When to use

• Auto-creating devices, interfaces, and IP addresses from a fabric design object
• Generating BGP sessions from a topology design
• Creating any set of objects that should be derived from a design definition and kept in sync with it
• Any scenario where "given this design, create these objects" needs to run repeatedly as the design evolves

What it produces

Three components:

1. Target group — a CoreGeneratorGroup that defines which design objects trigger the generator
2. GraphQL query (.gql) — fetches the design object(s) the generator will act on
3. Python class (InfrahubGenerator subclass) — implements the async generate() method, uses self.client.create() with allow_upsert=True

Example prompts

• "Create a generator that takes a fabric design object and creates all spine and leaf devices with their loopback interfaces"
• "Write a generator that creates BGP sessions between all spine-leaf pairs defined in a topology design"
• "Generate IP address assignments for all interfaces based on a design's IP allocation scheme"

Key rules enforced

• allow_upsert=True — always set on self.client.create() calls; without it, re-running the generator creates duplicates instead of updating existing objects
• delete_unused_nodes=True — enables automatic cleanup of objects that were created by the generator but are no longer in the design; prevents orphaned objects from accumulating over time
• Target group — generator must reference a CoreGeneratorGroup; this is what connects design objects to the generator execution
• Async generate() method — the method signature must be async def generate(self, data):
• GraphQL query naming — query name must match the query class attribute

Common mistakes it catches

Mistake	What the skill does instead
Missing allow_upsert=True	Always includes it — prevents duplicate creation on re-run
Missing delete_unused_nodes=True	Always includes it — prevents orphaned objects
Sync generate() method	Uses async def generate(self, data):
Missing target group configuration	Generates the CoreGeneratorGroup definition

Running generators

Generators run automatically when a design object in their target group changes. To run a generator manually:

infrahubctl generator run <generator-name>