cli: show interactive session information

Currently we allow to open interactive sessions but users will forget they had them open, so we should display this information. It could look as follows:

$ reana-client workflows
NAME       RUN_NUMBER   CREATED               STATUS     INTERACTIVE
workflow   1            2019-03-04T16:11:11   created    *

workflow   2            2019-03-04T18:30:02   running    -
$ reana-client workflows -v
NAME       RUN_NUMBER   CREATED               STATUS    ID                                     USER                                   SIZE       INTERACTIVE_SESSION
workflow   1            2019-03-04T16:11:11   created   23e2fd73-bf16-4aaf-af37-ca74707c4b18   00000000-0000-0000-0000-000000000000   0          http://192.168.99.100:32107/23e2fd73-bf16-4aaf-af37-ca74707c4b18?token=<I_dream_I_am_a_token>
$ reana-client status -w workflow.1
NAME       RUN_NUMBER   CREATED               STATUS    PROGRESS    INTERACTIVE
workflow   1            2019-03-04T16:11:11   created   -/-         http://192.168.99.100:32107/23e2fd73-bf16-4aaf-af37-ca74707c4b18?token=<I_dream_I_am_a_token>

cc @tiborsimko

Some raw musings:

In the future, one could open several interactive sessions on the same workflow workspace, e.g. a notebook and a remote shell. It would be good to think about a display technique that can accommodate these future scenarios.
One could consider a dedicated "workflows" command and a dedicated "sessions" command, but we may also have a common list command that could do both, see #252 and #253, via some CLI options, say list --workflows and list --interactive-sessions.
Even for "batch" only workflows, there will be a Web UI that can display the workflow progress status and that can offer some "interactive" features such as to pause the workflow, to inspect logs of this and this concrete step, etc. Hence the UI column that may come handy also for batch workflows.

The choice is basically:

Expand the above table in the horizontal direction, as it were, and add new columns matching session types:

$ reana-client workflows
NAME       RUN_NUMBER   CREATED               STATUS     JUPYTER
workflow   1            2019-03-04T16:11:11   created    http://example.org/workflows/1/jupyter?foo=bar

Expand the above table in the vertical direction, as it were, and introduce new rows or separate the display for batch workflows and interactive sessions:

$ reana-client workflows
NAME       RUN_NUMBER   CREATED               STATUS     URI
workflow   1            2019-03-04T16:11:11   created    http://example.org/workflows/1/dashboard
workflow   2            2019-03-04T16:20:11   created    http://example.org/workflows/2/dashboard

$ reana-client sessions
NAME       RUN_NUMBER   CREATED               SESSION     URI
workflow   1            2019-03-04T16:11:11   jupyter     http://example.org/workflows/1/jupyter?foo=bar
workflow   1            2019-03-04T17:11:11   shell       http://example.org/workflows/1/shell

I'd be leaning towards something like the later, as it is more expandable.

P.S. Note that the future Web UI would also list any open interactive session for the currently display workflow, which would be probably more natural interface than CLI for those...

reanahub / reana-client

cli: show interactive session information #262