Error when worker version doesn't match server #307

[fpiedrah]

Fixes #307

• Add turbina.__version__ to the TurbinaTask class as an attribute
• Validate versions in TurbiniaTask.run_wrapper() before TurbiniaTask.run() is ever ran

[googlebot]

Thanks for your pull request. It looks like this may be your first contribution to a Google open source project (if not, look below for help). Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

📝 Please visit https://cla.developers.google.com/ to sign.

Once you've signed (or fixed any issues), please reply here (e.g. I signed it!) and we'll verify it.

---

What to do if you already signed the CLA

Individual signers

• It's possible we don't have your GitHub username or you're using a different email address on your commit. Check your existing CLA data and verify that your email is set on your git commits.

Corporate signers

• Your company has a Point of Contact who decides which employees are authorized to participate. Ask your POC to be added to the group of authorized contributors. If you don't know who your Point of Contact is, direct the Google project maintainer to go/cla#troubleshoot (Public version).
• The email used to register you as an authorized contributor must be the email used for the Git commit. Check your existing CLA data and verify that your email is set on your git commits.
• The email used to register you as an authorized contributor must also be attached to your GitHub account.

[fpiedrah]

@aarontp Hi! I've been looking at the code and I've got new questions

1. I've added TurbiniaTask.turbina_version = turbina.__version__ this will give us the task version inside the class. I need to validate the matching server information in TurbiniaTask.run_wrapper() how would I get the server version from this task?
2. This validation should run before TurbiniaTask.run() once this mismatch is found the TurbiniaTask.run_wrapper() should yield an error?
3. Do I need to add version to the TurbiniaServer class?

Sorry for the amount of questions, but I rather understand the whole thing so I can be useful by contributing to other issues too. : )

[aarontp]

Hello: No worries, I think it's better to ask questions than get too far and have to change a bunch of code too, :)

1. The TurbiniaTask is actually created server side, so the version that is an attribute of that object will actually be the version that the server is running. Then the Worker can compare the task.version directly against turbinia.version (which should be the version that the Worker started with).

2. Yes, it will result in an error, but the way the error will be sent back to the server is by returning the error in the TurbiniaTaskResult object (should be self.result from the Task code). You can add it as an error, and also set a relevant status message (this status is what will bubble up to the user in a turbiniactl status command).

3. I don't think you'll need to add it there, but let me know if you have any other questions related to this.

[fpiedrah]

@aarontp I keep being confuse with some things

1. TurbiniaTask is the server side portion of the whole thing, but the remote execution happens with the Turbinia TaskManager does this mean that when I compare versions I should do that using the TurbiniaTaskResult object returned from running TurbiniaTask.setup() meaning that TurbiniaTaskResult should have a field with the version? I'm confuse because I don get from where I could get the remote objects version.

2. Now this is clear now, with the returned TurbiniaTaskResult, that will be the self.result, I'll have to add a meaningful TurbiniaTaskResult.status and TurbiniaTaskResult.error for the version mismatch.

Thanks for the help!

[aarontp]

Hello:

I've made a couple comments on the PR, and here are some responses to your earlier questions:

1. So the TurbiniaTask is created on the server, but it actually gets scheduled via a task scheduler to execute on a different worker. Since it gets created server-side, when you initially set the turbinia version in TurbiniaTask.__init__(), that will be the server version. Then, when the worker starts, it will have it's own turbinia.version variable that will be the Worker version, and that can be compared like you're doing in the run_wrapper(). The TurbiniaTaskResult() won't need to have the version as an attribute.
2. Yep, sounds good. I left comments on the code before I saw your comments, so I left a similar comment there.

TL;DR: I think you have the comparison correct, we just need to update it to return the results with the error (as you mention).

[fpiedrah]

I signed it!

[googlebot]

CLAs look good, thanks!

[aarontp]

LGTM, thanks!