Load Patroni data to DuckDB
Build a Patroni to DuckDB pipeline with your coding agent. One prompt scaffolds it with the dltHub AI harness, plus the Patroni API base URL, auth, endpoints, and incremental loading.
Patroni is a template for high-availability PostgreSQL solutions that provides a REST API for cluster management, monitoring, and failover orchestration. Everything needed to build a working Patroni → DuckDB pipeline is on this page: the API's base URL, authentication, endpoints, pagination and incremental field — plus a prompt that hands the whole job to your coding agent.
Build your Patroni to DuckDB pipeline
Paste this prompt into Claude, Codex, or Cursor. The agent does the rest.
PromptRunuvx dlthub-init@latestto build a pipeline from Patroni to DuckDB and run it on dltHub
That scaffolds a dltHub workspace and installs the dltHub AI harness — the project rules, the secrets-management skill, and the dlt MCP server your agent needs to work safely. From there it reads the Patroni API, proposes the endpoints to load, then writes, runs and validates the pipeline while you review rather than type. Credentials are inspected through MCP tools, so your agent never reads secrets.toml itself. How the LLM-native workflow works →
Prefer to write it yourself? Every fact the agent uses is below.
Patroni API at a glance
| Base URL | http://<host>:<port> |
| Example endpoint | GET health |
| Authentication | Unsafe endpoints support HTTP Basic auth; all endpoints support optional mTLS — sent in the Authorization header, prefixed Basic |
| Pagination | Not paginated |
| API reference | https://patroni.readthedocs.io/en/latest/security.html |
These values come from the Patroni API reference — the authoritative source if anything here looks out of date.
How do I authenticate with the Patroni API?
The Patroni REST API supports HTTP Basic authentication for unsafe endpoints (POST, PUT, PATCH, DELETE) and mTLS for all endpoints. Basic authentication requires the standard 'Authorization' header with a base64-encoded 'username:password' string.
1. Get your credentials
Patroni does not use traditional "API keys" or a web dashboard for setup. Instead, you configure security directly in the Patroni YAML configuration file (under the restapi section) or via environment variables. To set up basic authentication: 1. Edit the restapi section in your Patroni configuration file. 2. Define authentication.username and authentication.password (or set PATRONI_RESTAPI_USERNAME and PATRONI_RESTAPI_PASSWORD environment variables). 3. Restart the Patroni service to apply changes. For enhanced security, enable TLS by providing certfile, keyfile, and optionally cafile paths. When enabled, Patroni switches to HTTPS, allowing for mutual TLS (mTLS) authentication if verify_client is configured.
2. Add them to .dlt/secrets.toml
[sources.patroni_source] restapi_username = "your_username" restapi_password = "your_password"
dlt reads this file automatically at runtime. With the harness, the setup-secrets skill prompts you for the values and never handles the raw credential in chat. For production, see setting up credentials with dlt.
What Patroni data can I load into DuckDB?
These are the Patroni endpoints dlt can load into DuckDB:
| Resource | Endpoint | Method | Data selector | Description |
|---|---|---|---|---|
| health | /health | GET | Returns 200 if PostgreSQL is running. | |
| liveness | /liveness | GET | Returns 200 if Patroni heartbeat loop is running. | |
| readiness | /readiness | GET | Returns 200 if node is leader or ready for replication. | |
| metrics | /metrics | GET | Returns Patroni metrics in Prometheus format. | |
| config | /config | GET | Returns the current dynamic configuration. |
How do I load only new Patroni records?
The Patroni API reference does not document a timestamp or sequence field for these endpoints, so there is nothing to advertise here as verified. Pick a field from the endpoints table above that increases with every write, then set it as the cursor_path.
{"name": "health", "endpoint": { "path": "health", # Replace with a field that increases on every write. "incremental": {"cursor_path": "REPLACE_ME", "initial_value": "2024-01-01T00:00:00Z"}, }}
On the first run dlt loads everything from initial_value; on every run after that it requests only what changed and appends with write_disposition="merge" if you set a primary key. See incremental loading.
What does the generated Patroni pipeline look like?
A standard dlt REST API pipeline — the same code you would write by hand, loading /health and /restart from the Patroni API into DuckDB:
import dlt from dlt.sources.rest_api import RESTAPIConfig, rest_api_resources @dlt.source def patroni_source(username_password=dlt.secrets.value): config: RESTAPIConfig = { "client": { "base_url": "http://<host>:<port>", "auth": {"type": "http_basic", "username": "REPLACE_ME", "password": username_password}, }, "resources": [ {"name": "health", "endpoint": {"path": "health"}}, {"name": "config", "endpoint": {"path": "config"}} ], } yield from rest_api_resources(config) def load_patroni_to_duckdb() -> None: pipeline = dlt.pipeline( pipeline_name="patroni_pipeline", destination="duckdb", dataset_name="patroni_data", ) load_info = pipeline.run(patroni_source()) print(load_info) if __name__ == "__main__": load_patroni_to_duckdb()
Run it with python patroni_pipeline.py. The agent iterates on this until it loads cleanly — you review and approve, rather than write it from scratch.
How do I query Patroni data in DuckDB?
dlt creates one table per resource. Query the loaded data with Python or SQL — or ask your agent to, through the MCP server's execute_sql_query tool.
Python (pandas DataFrame):
import dlt data = dlt.pipeline("patroni_pipeline").dataset() df = data.health.df() print(df.head())
SQL:
SELECT * FROM patroni_data.health LIMIT 10;
See querying your data with dataset and exploring it in marimo notebooks.
How do I deploy the Patroni to DuckDB pipeline in production?
The pipeline runs locally, which is ideal for prototyping and one-off analysis. When you need it on a schedule, monitored on every load, and shared with your team, deploy the same dlt code on the dltHub platform — no infrastructure to maintain. The prompt above already ends with "run it on dltHub", so your agent can take it there directly.
- Deploy & schedule — run the pipeline as a managed job with automatic retries.
- Monitor — observable job queues, alerting, and load metrics for every run.
- Transform — promote raw Patroni loads into governed, documented models.
- Visualize & share — explore data in notebooks and publish live dashboards instead of static screenshots.
What other destinations can I load Patroni data to?
dlt loads into any of these — only the destination argument changes:
| Destination | Example value |
|---|---|
| PostgreSQL | "postgres" |
| BigQuery | "bigquery" |
| Snowflake | "snowflake" |
| Redshift | "redshift" |
| Databricks | "databricks" |
| Filesystem (S3, GCS, Azure) | "filesystem" |
Set dlt.pipeline(destination="snowflake") and add credentials in .dlt/secrets.toml. On the dltHub platform the same pipeline runs against a managed Iceberg lakehouse. See the full destinations list.
Next steps
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