[sujen1412]

Closes #8

Changes

• get_maap_pgt_token.py: requests go through a session with HTTPAdapter(Retry(...)): (5, 30) s timeout, up to 5 retries (6 attempts), exponential backoff with jitter (backoff_factor=1, backoff_jitter=1, backoff_max=30), retrying connect errors, timeouts and 5xx. raise_on_status=False so the final response is turned into a clear PgtTokenError. 4xx (not retried), a missing session_key and non-JSON bodies also raise PgtTokenError.
• On failure the message goes to stderr (stdout is captured into MAAP_PGT, so the old stdout print never reached _stderr.txt), _alt_error.txt is written so HySDS uses it as the job error, and the script exits with code 78.
• dps_wrapper.sh: || exit $? so the failure code propagates out of the command substitution.
• MAAP_API_HOST is now read at call time rather than import time.
• urllib3>=2 added to the Dockerfile pip install and the CI test job: Retry(backoff_jitter=...) needs urllib3 2.x. Resolving the image's unpinned deps for Python 3.12 gave urllib3 2.8.0 already; the pin guards against a future downgrade. The local Python 3.9 .venv has urllib3 1.26 and cannot run these tests.

Notes

• Exit code 78 was chosen per hysds-agent's reading of job_worker.py: any non-zero code yields "Got non-zero exit code: N", and _alt_error.txt in the job dir overrides error. Codes 126/127/130/137/143 and -15 are avoided. That guidance is from reading the code, not from a run on HySDS.
• Assumes the wrapper's cwd is the job dir when _alt_error.txt is written; not verified in the container.

Tests

tests/test_get_maap_pgt_token.py: retry behaviour is tested against a local flaky HTTP server (5xx then success, exhaustion after 6 attempts, 4xx not retried, connection errors), plus error messages, _alt_error.txt/stderr, and exit code 78 with clean stdout. Full suite: 73 passed on Python 3.12 / urllib3 2.8.0.