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Cruncher

Adapters

Cruncher supports a flexible adapter system, allowing you to connect to and query data from a variety of sources. Adapters are responsible for connecting to external systems, extracting fields, and providing data to Cruncher in a unified format.

What is an Adapter?

An adapter is a module that knows how to communicate with a specific backend or data source (such as Grafana Loki, Docker logs, or mocked/test data). It extracts fields from the source data and exposes them to Cruncher for querying and analysis.

Built-in Adapters

Cruncher comes with several built-in adapters, including:

  • Grafana Browser Adapter: Connects to Grafana Loki via the browser, allowing you to query logs and metrics from your Grafana instance.
  • Docker Adapter: Reads logs from Docker containers.
  • Mocked Data Adapter: Provides sample/mock data for testing and demos.

Configuring Adapters

Adapters are configured in the Cruncher config file (~/.config/cruncher/cruncher.config.yaml). Each adapter entry specifies the type, name, and any required parameters. For example:

connectors:
  - type: grafana_browser
    name: main
    params:
      grafanaUrl: <your_grafana_url>
      uid: <your_loki_uid>
      # ...other params...
  - type: docker
    name: docker_logs
    # ...params...

See the installation guide and configuration reference for more details.

How Adapters Work

  • Adapters extract fields and assign types to each field.
  • Controller parameters in your QQL queries are passed directly to the adapter, allowing for efficient server-side filtering.
  • Once data is loaded, you can use all of Cruncher’s QQL features to analyze and transform it.

Writing Your Own Adapter

Cruncher is designed to be extensible. You can implement your own adapter by following the patterns in the src/adapters/ directory. Adapters must expose a controller and implement the required interface for data extraction and field typing.

Adapters make Cruncher a powerful tool for querying and analyzing data from many different sources, all with a consistent query experience.