Logs

The Data Access Tool backend produces logs from two primary sources:

• Flask/API application logs produced through the use of e.g., app.logger.info and unhandled exceptions.
  • In dev, the Flask dev server produces logs that can be viewed with docker compose logs.
  • In non-dev environments, the gunicorn server produces logs that can be viewed with docker compose logs.
• NGINX error and access server logs, which are written to local disk.

NGINX Server logs

Logs are written to local disk, in a directory defined by LOGS_SHARE_PATH.

It is expected that these logs be backed-up to a networked share drive (defined through the LOGS_SHARE_BACKUP_PATH environment variable) through logrotation. The dat.access.log is intended to be used for application metrics, and these data should be retained for recordkeeping. The data-access-tool-vm project sets up logrotation for NSIDC deployments.

Each line of the NGINX access logs are formatted as JSON so that the /api/metrics endpoint can easily parse the records.

An example line from an access log:

{
  "http_user_agent": "Mozilla/5.0 (X11; Linux x86_64; rv:137.0) Gecko/20100101 Firefox/137.0",
  "args": "",
  "uri": "/api/status",
  "http_referer": "https://dev.data-access-tool.trst2284.dev.int.nsidc.org/",
  "body_bytes_sent": "551",
  "status": "200",
  "request": "GET /api/status HTTP/1.1",
  "time_iso8601": "2025-04-14T14:31:03+00:00",
  "remote_addr": "111.111.111.111",
  "x_forwarded_for": "12.345.678.911, 111.111.111.111"
}