Allow configuring a command to be automatically run when disconnecting from VPN

jherland commented 3 years ago

I configure my SSH with ControlMaster connections that must be closed when I disconnect from VPN, otherwise they are left stale and existing and future SSH session are left hanging/wedged.

To accomodate this, the last patch in this series teaches openconnect-sso automatically run a configured command on VPN disconnection. In my case, I run a shell script that does ssh -O exit ... on my connections, although this doesn't matter from openconnect-sso's POV.

Otherwise the other patches are only tangentially related:

Patch#1 stops openconnect-sso from crashing when the config file cannot be written. It allows me to control the openconnect-sso configuration via home-manager (which stores a symlink to a read-only file in the Nix store).
Patch#2 fixes the control flow on Ctrl+C to run any except/finally clauses in coroutines, instead of aborting straight out of async mode into app.py:run(). The patch does this by using asyncio.run() (new in Python v3.7). There may be a different way to achieve this that retains v3.6-compatibility, but I could not easily find it.
Patch#3 is a merely a consequence of upping the minimum Python version from 3.6 to 3.7.

FWIW, I also have the same series rebased onto the develop branch in my fork.

vlaci commented 3 years ago

Very nice! I'd very much like to keep python 3.6 compatibility as I know a bunch of folks who still use it.

vlaci commented 3 years ago

It may not worth to run openconnect on the event loop. A traditional subprocess.run call may suffice. This would work around the quirks of asyncio in 3.6.

jherland commented 3 years ago

Yes, AFAICS we simply run openconnect at the end, and there's no concurrency or real asynchronicity remaining at that point, so it should be fairly straightforward to "leave" async mode before then.

jherland commented 3 years ago

Superseded by https://github.com/vlaci/openconnect-sso/pull/33

vlaci commented 3 years ago

You may force push to the existing branch you prepared the PR from, it automatically updates the PR itself. No need to create new pull requests in such cases.

vlaci / openconnect-sso

Allow configuring a command to be automatically run when disconnecting from VPN #32