Constants and environment

Juturna uses a set of global constants to manage internal configurations, such as plugin locations, hub repositories, and threading timeouts. While these constants have sensible defaults, you can override them using environment variables to suit your deployment needs.

This guide explains how to modify these configurations and ensures your environment variables are typed correctly.

Using constants

You can access Juturna constants using the meta module:

>>> import juturna as jt
>>> dir(jt.meta)
['JUTURNA_BASE_REPO',
 'JUTURNA_CACHE_DIR',
 'JUTURNA_HUB_TOKEN',
 'JUTURNA_HUB_URL',
 'JUTURNA_LOCAL_PLUGIN_DIR',
 'JUTURNA_MAX_QUEUE_SIZE',
 'JUTURNA_THREAD_JOIN_TIMEOUT',
 ...
]
>>> jt.meta.JUTURNA_BASE_REPO
https://github.com/meetecho/juturna

Overriding defaults

To change a configuration, export the variable in your shell before running Juturna.

# changing the cache directory and increasing the queue size
export JUTURNA_CACHE_DIR="/tmp/juturna_cache"
export JUTURNA_MAX_QUEUE_SIZE="2000"

# launch your pipeline
python -m juturna launch --config my_pipeline.json

Type validation (1.0.1-beta)

Juturna enforces strict type checking on environment variables. The system attempts to cast your environment variable to the type of the default value.

If you provide a value that cannot be converted (for example, providing a string “fast” for the integer JUTURNA_THREAD_JOIN_TIMEOUT), the system will log an error and raise a RuntimeError.

Handling boolean variables

When setting configuration flags that are boolean, Juturna parses specific string values to determine truthiness.

To set a boolean variable to True, use one of the following case-insensitive values: true, 1, and yes. Any other value will be interpreted as False (unless it fails type conversion).

# enabling a hypothetical boolean flag
export JUTURNA_BOOL_FLAG="yes"

Available configuration variables

If a variable is not set, Juturna falls back to the default values defined in juturna.meta._constants.

You can customize the following variables in your environment.

Repository and Hub Settings

  • JUTURNA_BASE_REPO: The base URL for the Juturna repository.

    • Default: https://github.com/meetecho/juturna

  • JUTURNA_HUB_URL: The API URL used to query and download plugins.

    • Default: https://api.github.com/repos/meetecho/juturna/contents/plugins/

  • JUTURNA_HUB_TOKEN: An authentication token for the Hub.

    • Default: Empty string

File System Paths

  • JUTURNA_CACHE_DIR: The directory where downloaded plugins are cached.

    • Default: ~/.cache/juturna (user’s home directory)

  • JUTURNA_LOCAL_PLUGIN_DIR: The directory used for local plugin discovery.

    • Default: ./plugins

Performance Tuning

  • JUTURNA_MAX_QUEUE_SIZE: The maximum size of the internal queues used by nodes.

    • Default: 999

  • JUTURNA_THREAD_JOIN_TIMEOUT: The time (in seconds) to wait for threads to join during a stop procedure.

    • Default: 2.0

Hub-related constants and hub features are not ready for use (1.0.1-beta)

Hub features are still in development, so you should expect breaking changes and bugs. If you find any of the latter, please report them on GitHub. We are working hard to make the hub a reality, and we are looking for your feedback to make it better.

Working with env variables

Section under construction