[sarankumar1325]

push_to_gateway, pushadd_to_gateway and delete_from_gateway put a job or grouping key value of . or .. into the URL path unchanged, for example /metrics/job/my_job/instance/... Those are dot segments. The Pushgateway router cleans the path and replies with a 307 redirect to a different group (.. points at the parent group), so the call fails with HTTP Error 307: Temporary Redirect.

This change base64-encodes these two values, the same way values with / or spaces are already handled. client_golang's push package does the same thing.

Reproduction against Pushgateway v1.11.5:

push_to_gateway("localhost:9091", job="j", grouping_key={"instance": ".."}, registry=r)
# before: urllib.error.HTTPError: HTTP Error 307: Temporary Redirect
# after:  stored as {"instance": "..", "job": "j"}

Tests:

• Added test_push_with_groupingkey_dot_segments and test_push_with_dot_segment_job to tests/test_exposition.py. Both fail on master and pass with this change.
• The full suite passes (451 passed, 3 skipped), and flake8 and isort are clean.
• Checked by hand against a local Pushgateway v1.11.5: push and delete with . and .. values now succeed.

I used an AI assistant while preparing this change. I reviewed and tested it myself.