Connect using a SSH transport

[meeuw]

Description

Connect using a SSH transport

This only works when paramiko is installed, I don't know if we want to hard depend on paramiko (with all it's dependencies).

Checklist

• I've added this contribution to the changelog.md.
• I've added my name to the AUTHORS file (or it's already there).

[codecov-io]

Codecov Report

Merging #634 into master will decrease coverage by 0.03%.
The diff coverage is 75.6%.

@@            Coverage Diff             @@
##           master     #634      +/-   ##
==========================================
- Coverage   78.05%   78.02%   -0.04%     
==========================================
  Files          26       26              
  Lines        2297     2334      +37     
==========================================
+ Hits         1793     1821      +28     
- Misses        504      513       +9

Impacted Files	Coverage Δ
mycli/completion_refresher.py	94.91% <ø> (ø)	⬆️
mycli/sqlexecute.py	86.91% <73.07%> (-2.32%)	⬇️
mycli/main.py	77.37% <80%> (+0.12%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 7b0e527...7b97f8f. Read the comment docs.

[tsroten]

@meeuw It looks like paramiko will already call getpass.getuser() if the username is None. So, maybe we don't need this on the mycli side?

[meeuw]

thanks, you're right.

[tsroten]

@meeuw I'm not sure exactly what my issue is, but I can't get this to work on python 2.7 or 3.6. I get an error 'Channel' object has no attribute 'recv_into'. It looks like this might fix it: paramiko/paramiko#553

@grooverdan mentions that PR is required on a PyMySQL issue: PyMySQL/PyMySQL#77

[meeuw]

That's stange! I presume you're testing this on MacOS? Have you tried running it on Linux?

[tsroten]

@meeuw Yeah, that was tested on Linux (both a Linux client and a Linux server).

I just tested a MacOS client connecting to a Linux SSH server and that worked fine. I'm going to do some more testing with some Linux boxes real quick.

[tsroten]

@meeuw Okay, everything continues to work well on the MacOS computer. On the Linux servers I got a variety of errors, some of which I think are related to the ssh server configuration. I'm not too worried about that at this point.

One thing we might want to improve (not in this pull request) is that use opens up a new connection. So, when you are using SSH, it opens another SSH connection and then another database connection. It potentially takes a second or two. That's unnecessary since all use is ultimately doing is setting the sqlexecute.dbname instance variable and triggering the completions thread to run. A new connection isn't needed. But, that's an existing issue, not related to the SSH changes.

I added a couple of changes to the click help messages.

I do think we should add paramiko to the setup.py file, maybe under the optional name ssh. What do you think?

[meeuw]

Yes, it's a good idea to add an optional name in setup.py for ssh, just committed that.
I only see this as a convenience feature, I'll definately keep using my own tunnel script to reuse the same ssh connection.