Giving some love to Spot instances

[peterdeme]

Description of the change

I have looked into our launcher/worker code recently and I have noticed that it'd quite easy to detect Spot Instance interruption signals, so I implemented a graceful shutdown behavior in our code.

I thought I'll explicitly mention some details in our TF module as well. If it functions as I expect it to, I'll extend our official documentation as well.

edit: I was able to test it and it works :)

Type of change

• Bug fix (non-breaking change that fixes an issue);
• New feature (non-breaking change that adds functionality);
• Breaking change (fix or feature that would cause existing functionality to not work as expected);
• Documentation (a documentation or example fix not affecting the infrastructure managed by this module);

Checklists

Development

• All necessary variables have been defined, with defaults if applicable;
• The code is formatted properly;

Code review

• The module version is bumped accordingly;
• Spacelift tests are passing;
• This pull request has a descriptive title and information useful to a reviewer. There may be a screenshot or screencast attached;
• This pull request is no longer marked as "draft";
• Reviewers have been assigned;
• Changes have been reviewed by at least one other engineer;

[peterdeme]

This is a recent development in the worker code that I did last night. I'm still testing it.

[peterdeme]

just tested it and it works :)

[TheOutdoorProgrammer]

is this just the example and docs? where is the rest?

[peterdeme]

@Apollorion there is no rest, this is just documentation. we were always compatible with spot, we just never really recommended them.

[TheOutdoorProgrammer]

ah, I read this on my phone earlier and it looked like a variable was being added and not used. But now that Im looking at it on the computer this makes more sense.