Model Repository Backend
The Maize Model Repository is the Spring Boot backend for the Workflow Management Engine (WME). It is the contract boundary between the Workflow Editor, persisted catalog data, worker provisioning, Airflow DAG execution, Logstash/Kibana services, Flower worker discovery, and the AI Logstash assistant.
Use this guide when you need to integrate against backend APIs, understand backend code structure, or reason about side effects triggered by saving processors and workflows.
Backend Responsibilities
The backend owns:
- user-scoped catalog persistence in MongoDB;
- Data Interface Type, Digital Resource, Data Kind, Worker Asset, Processor Definition, Processor Manifest, Workflow, Workflow Template, Observation, and Settings APIs;
- processor source provisioning onto registered workers;
- Airflow DAG rendering, distribution, run monitoring, and log retrieval;
- Logstash pipeline file generation and pipeline status monitoring;
- Kibana data-view and visualization link resolution;
- encrypted registry and GitHub token storage;
- Keycloak JWT validation and user identity extraction.
The frontend never talks directly to workers, Airflow, MongoDB, Logstash, Kibana, or Flower. Those calls go through the backend.
Service Dependencies
| Dependency | Role | Typical config |
|---|---|---|
| MongoDB | Stores catalog entities, settings, workflow templates, observations, and status records. | MONGO_* env vars |
| Keycloak | Issues JWTs used by the editor and API clients. | KEYCLOAK_* env vars |
| Worker daghandler | Receives processor folders and generated DAG files. | Worker Asset IP / PORT, plus WORKER_API_PORT default |
| Airflow webserver | Runs and reports workflow DAG executions. | AIRFLOW_BASE_URL, AIRFLOW_USERNAME, AIRFLOW_PASSWORD |
| Logstash | Loads generated pipeline configuration and exposes monitoring metrics. | LOGSTASH_* env vars |
| Kibana | Provides data views, Discover links, and generated visualization destinations. | KIBANA_* env vars |
| Flower | Lists live Celery workers for import into WME. | FLOWER_* env vars |
| AI chat service | Streams Logstash filter suggestions. | AI_* env vars |
The backend listens on SERVER_PORT, usually 9090. SpringDoc is exposed by the backend at /swagger-ui.html and /v3/api-docs.
Source Of Truth
Use the generated OpenAPI document for exhaustive request and response schemas. Use these public docs for onboarding, conventions, examples, and side-effect summaries.
The backend repo also contains internal flow notes under maize-model-repository/docs/:
- processor definition provisioning;
- worker registration fan-out;
- workflow save/run flows;
- auth and settings token handling.
Keep detailed controller annotations, DTO/entity details, and internal diagrams in the backend repo. Keep public usage guidance and curated examples in this docs site.
Backend Guide Map
- API Reference - endpoint groups, auth, pagination/search conventions, and examples.
- Code Structure - package/layer map and where to change behavior.
- Domain Model - glossary of core backend objects.
- Operations - side-effectful flows and runtime contracts.