youvegotdata

Uses RabbitMQ to send new file notifications, with the ultimate purpose of getting the file metadata into the Data Inventory Database.

The "producer" youvegotdata.py will usually be called by the CIRA data ingest scripts when a new file is added to the CIRA data stores, and will send a message through RabbitMQ to the consumers with the file's metadata.

Message "consumers" will be running to receive the file metadata and insert it into the database. It is expected that multiple consumers process will be accepting messages in RabbitMQ's "fair dispatch" configuration. A given notification will be received by one consumer.

Installing youvegotdata

This module requires Python 3.8 or greater. It is deployed to PyPi, so it can be installed with:

pip install youvegotdata

Which will install the ygd CLI command in your current Python environment.

Library usage

youvegotdata is also importable as a plain Python package so that ingest scripts can send notifications programmatically instead of shelling out to the ygd CLI. The public API is re-exported from the top-level package:

from youvegotdata import (
    Config,
    ConfigError,
    Notification,
    load_config,
    resolve_data_store,
    send_notification,
)

Loading configuration

load_config() reads and validates ~/.config/youvegotdata/config.ini (the same file the CLI uses) and returns a frozen Config dataclass. Validation errors raise ConfigError:

try:
    config = load_config()
except ConfigError as exc:
    print(f"configuration problem: {exc}")
    raise

To point at a specific file (e.g. for tests), pass an explicit path:

config = load_config("/path/to/config.ini")

The returned Config exposes rmq_host (str) and ceph_ips (dict[str, list[str]]).

Resolving a data store from a filepath

resolve_data_store maps a local path to its data store name and a store-relative path. It reads /proc/self/mountinfo, so it only works on Linux:

data_store, store_path = resolve_data_store("/data/file.hdf", config.ceph_ips)

Sending a notification

Build a Notification and pass it (plus a Config) to send_notification. It publishes one durable JSON message to the file_notif_queue queue and returns True on success or False if the data store could not be resolved. RabbitMQ errors are logged and re-raised as pika.exceptions.AMQPError:

notification = Notification(
    filepath="/data/file.hdf",
    product="VIIRS",
    version="1.0",
    start_time="2024-01-01T00:00:00",
    end_time="2024-01-01T01:00:00",
    length=1024,
    checksum="abc123",
    checksum_type="md5",
)
send_notification(notification, config)

Only filepath is required; the rest default to None.

Backward compatibility

The v1.x function produce_notification(config, filepath, ...) is kept as a deprecated shim that emits a DeprecationWarning and forwards to send_notification. It still accepts a raw configparser.ConfigParser or a Config. New code should use send_notification instead.

Running youvegotdata.py as ygd

Create the ~/.config/youvegotdata/ directory if it does not already exist. Create a config.ini file in this directory that looks like:

[Settings]
RMQ_HOST = <host of the RabbitMQ server>

[Data-store-mappings]
# The list of common Ceph IPs for every Ceph data store
# A dictionary of lists. This must be valid JSON: double quotes, no trailing commas.
CEPH_IPS = {"name": ["IP", "IP", "IP"], "name2": ["IP", "IP", "IP"]}

And fill it in with the RabbitMQ server's host name, and the IP address mappings across different Linux versions for the Ceph data stores.

Run the code with:

ygd [-h] [-v] [-p PRODUCT] [-r VERSION] [-s START_TIME] [-e END_TIME] [-l LENGTH] [-c CHECKSUM] [-t CHECKSUM_TYPE] filepath

Run this with the -h (--help) argument to see the available flagged arguments.

This will usually be run with just the filepath argument. An example is:

ygd /full/path/to/local/file/data_file.hdf

The filepath file must exist on the local machine.