feat(exclusive_route transform): implements new transform

[pront]

Summary

Introduces the new exclusive route transform. This is transform is very similar to the route transform but it acts like switch statement for routes (vs matching more than one route).

We did consider adding extra options to the existing route transform, but the route transform has an unordered list of routes and so we'd need to further complicate the UX of that transform by either adding a weight parameter to each route to order them (opening a question of what to do if the weights are the same for two routes) or by migrating the route configuration from a map to a list (while ideally maintaining backwards compatibility).

Change Type

• Bug fix
• New feature
• Non-functional (chore, refactoring, docs)
• Performance

Is this a breaking change?

• Yes
• No

How did you test this PR?

Does this PR include user facing changes?

• Yes. Please add a changelog fragment based on our guidelines.
• No. A maintainer will apply the "no-changelog" label to this PR.

Checklist

• Please read our Vector contributor resources.

References

• Closes: Add option to make routes exclusive #17040
• Ref: Mutually exclusive routing in the route transform #9100

[pront]

TODO: add CUE doc. Opening it up for comments.

[datadog-vectordotdev]

Datadog Report

Branch report: pront/exclusive-route-transform
Commit report: b0df5b1
Test service: vector

✅ 0 Failed, 7 Passed, 0 Skipped, 25.46s Total Time

[jszwedko]

Nice! I left a few comments below, but otherwise this looks good to me. I considered some other possible names for this transform (branch, switch, split, etc.) but I think the exclusive_route name makes its relationship to route clear.

[jszwedko]

Note that, in addition to the cue doc you mentioned is still TODO, you'll need to create a markdown file for the transform too.

[pront]

create a markdown file for the transform too.

Updated the PR with a lot of doc related changes. Not sure about this comment. Let me know if I missed something 🙏

[jszwedko]

I think you are still missing the markdown file so the new transform docs won't be rendered on the website. You'll need to create website/content/en/docs/reference/configuration/transforms/exclusive_route.md. Hugo uses that to generate the transform page (theoretically these pages could be generated from the cue docs, I think, but they currently aren't).

[jszwedko]

👍 appreciate you adding this at the same time.

[jszwedko]

I think you mentioned you'd be writing a blog post on this one. I think a release highlight might be appropriate too (or instead of the blog): https://vector.dev/highlights/.

[jszwedko]

Thanks for the updates!

It looks like website/cue/reference/components/transforms/exclusive_route.cue is empty 🤔

[jszwedko]

👍

[pront]

Thanks for the updates!

It looks like website/cue/reference/components/transforms/exclusive_route.cue is empty 🤔

ACK, I will add it soon.

[jorgehermo9]

have you thought about adding a exclusive: true | false flag to the existing route transform? is it worth to add a completely new one for this usecase?

[jszwedko]

have you thought about adding a exclusive: true | false flag to the existing route transform? is it worth to add a completely new one for this usecase?

We did consider that, but the existing route transform has an unordered list of routes and so we'd need to further complicate the UX of that transform by either adding a weight parameter to each route to order them (opening a question of what to do if the weights are the same for two routes) or by migrating the route configuration from a map to a list (while ideally maintaining backwards compatibility).

[pront]

have you thought about adding a exclusive: true | false flag to the existing route transform? is it worth to add a completely new one for this usecase?

We did consider that, but the existing route transform has an unordered list of routes and so we'd need to further complicate the UX of that transform by either adding a weight parameter to each route to order them (opening a question of what to do if the weights are the same for two routes) or by migrating the route configuration from a map to a list (while ideally maintaining backwards compatibility).

Well said, added this to the PR summary 👍