[agent_docker] Cannot scp during debug mode

[anthonygego]

Describe the bug When a submission is triggered in SSH debug mode, scp does not work and always returns Permission denied, even when specifying password as authentication method. It seems this could be caused by the interactive-ness of the shell, and probably https://github.com/UCL-INGI/INGInious/blob/61ead04267da9c1e4c0897474d3f98c8bc73d59a/base-containers/base/inginious_container_api/utils.py#L79

(to be confirmed)

INGInious installation details

• Version: v0.8+

To Reproduce Steps to reproduce the behavior:

1. Launch a submission using SSH debug mode
2. Use scp with the same host, port and SSH options
3. scp closed with Permission denied

[nrybowski]

Do we really want allowing scp'ing files in both directions? What about a size limit on the amount of data that one can transfer in/from the container?

From what I understood of the use case that triggered this issue, file size is undetermined and could possibly be quite large.