prefect-couchbase 1.0.0

Prefect collection for connecting flows and tasks to Couchbase.

prefect-couchbase

A Prefect collection for connecting Prefect flows and tasks to Couchbase through the official Couchbase Python SDK.

What you can use it for

• Store Couchbase connection details as a Prefect block and load them safely from flows.
• Read, write, and delete documents from Couchbase buckets/scopes/collections in Prefect tasks.
• Run SQL++ queries from Prefect flows while reusing the same Couchbase SDK connection lifecycle.

This connector does not replace the Couchbase Python SDK. It provides Prefect-native credentials and a small convenience wrapper around the SDK so workflows can manage credentials, lifecycle, and common operations consistently.

End-user quickstart

Install the package:

pip install prefect-couchbase

Create and save a credentials block:

from prefect_couchbase import CouchbaseCredentials

credentials = CouchbaseCredentials(
    connection_string="couchbases://cb.example.cloud.couchbase.com",
    username="analytics_user",
    password="super-secret-password",
)
credentials.save("prod-couchbase", overwrite=True)

Use the block from a flow:

from prefect import flow, task
from prefect_couchbase import CouchbaseCredentials


@task
def upsert_hotel(document_id: str, name: str) -> dict:
    credentials = CouchbaseCredentials.load("prod-couchbase")

    with credentials.get_connector(
        bucket="travel-sample", scope="_default", collection="_default"
    ) as couchbase:
        couchbase.upsert(document_id, {"type": "hotel", "name": name})
        return couchbase.get(document_id)


@flow
def demo() -> dict:
    return upsert_hotel("prefect::hotel::1", "Prefect Grand Hotel")


if __name__ == "__main__":
    print(demo())

Expected output:

{'type': 'hotel', 'name': 'Prefect Grand Hotel'}

Provision Couchbase

Recommended: Couchbase Capella

Use Capella when Prefect Cloud workers or any hosted execution infrastructure need to reach Couchbase over the public internet.

1. Create a Capella cluster.
2. Create or choose a bucket, scope, and collection.
3. Add a database user with access to the bucket.
4. Add the worker's outbound IP address to Capella's allowed IP list.
5. Use the Capella SDK connection string, which starts with couchbases://.
6. Configure the Prefect block with the connection string, username, and password.

Local or self-managed Couchbase

Use local/self-managed Couchbase when your Prefect worker runs on the same machine or private network.

1. Start Couchbase Server locally.
2. Create a bucket such as travel-sample or prefect-demo.
3. Create a user with bucket read/write permissions.
4. Use a connection string such as couchbase://localhost.

For a quick local evaluation, the Couchbase Python SDK examples and Docker documentation are the best reference for the currently supported server image and initialization flow.

Configuration reference

CouchbaseCredentials fields:

Field	Description
connection_string	Couchbase SDK connection string, such as couchbase://localhost or couchbases://cb.example.cloud.couchbase.com.
username / password	Password authentication credentials. Store these as Prefect secrets through the block.
cert_path	Optional trusted CA certificate path for password authentication; client certificate path for certificate authentication.
key_path / trust_store_path	Required with cert_path when using certificate authentication.
profile	Optional SDK config profile, for example wan_development.
options	Extra keyword arguments passed to couchbase.options.ClusterOptions.

CouchbaseConnector methods:

• get_bucket(bucket=None)
• get_scope(bucket=None, scope=None)
• get_collection(bucket=None, scope=None, collection=None)
• upsert(key, value, **kwargs)
• get(key, content_as=dict, **kwargs)
• remove(key, **kwargs)
• query(statement, *args, **kwargs)
• ping(**kwargs)
• close()

Tutorial: runnable local flow

1. Install dependencies:

   pip install prefect-couchbase
   

2. Export connection settings:

   export COUCHBASE_CONNECTION_STRING="couchbase://localhost"
   export COUCHBASE_USERNAME="Administrator"
   export COUCHBASE_PASSWORD="password"
   export COUCHBASE_BUCKET="travel-sample"
   

3. Save a credentials block once from the current environment:

   python examples/save_credentials_block.py
   

4. Run the example flow, which loads the saved block:

   python examples/couchbase_flow.py
   

5. Validate by checking that the flow prints:

   Stored document: {'type': 'hotel', 'name': 'Prefect Grand Hotel'}
   

Troubleshooting

• Authentication failed: verify username/password and bucket permissions.
• Unambiguous timeout: verify the worker can reach the cluster and that Capella allowed IPs include the worker.
• bucket must be provided: pass bucket="..." to get_connector() or to the individual operation.
• TLS errors with Capella: use a couchbases:// connection string and ensure the cluster endpoint is correct.

Developer documentation

Local development

git clone https://github.com/couchbase-examples/couchbase-prefect.git
cd couchbase-prefect
uv sync --extra dev

Run tests and coverage:

uv run pytest

Run linting:

uv run ruff check .
uv run ruff format --check .

Build the package:

uv run python -m build

Run the example smoke check without a live Couchbase cluster:

uv run python -m py_compile examples/save_credentials_block.py examples/couchbase_flow.py

Run the examples against a live cluster by setting the environment variables from the tutorial, saving the block with uv run python examples/save_credentials_block.py, and then executing uv run python examples/couchbase_flow.py.

Release and publishing path

1. Ensure uv run pytest, uv run ruff check ., and uv run python -m build pass.
2. Update the version tag according to the repository release policy.
3. Build distributions with uv run python -m build.
4. Publish to PyPI or the chosen private package index with twine upload dist/* after configuring maintainer credentials.
5. Register the collection with Prefect by installing the package in the worker environment. The package exposes the prefect.collections entry point prefect_couchbase = prefect_couchbase.

Research and design notes

This implementation follows Prefect's collection pattern from official integrations such as prefect-redis, prefect-snowflake, and prefect-sqlalchemy: typed Prefect blocks hold credentials and user code imports a small package-specific public API. It also mirrors the Couchbase authentication and collection access shape used by the Couchbase Airflow provider: password authentication uses PasswordAuthenticator, certificate authentication uses CertificateAuthenticator, and helper methods resolve bucket/scope/collection objects.

Known limitations

• The unit test suite uses SDK mocks so it can run without a live Couchbase service. Live connectivity should be validated in the environment where the Prefect worker runs.
• The connector intentionally exposes a minimal wrapper. Advanced SDK features should be accessed from connector.cluster or native SDK objects returned by get_bucket, get_scope, and get_collection.