About breaking change in CLI `tetra version` from `--client` to `--server`

[lucasfcnunes]

What happened?

This commit introduces a change in the tetra CLI that makes it incompatible with cilium (v1, stable) that works with the cilium version --client pattern. This issue might be of use to future cilium v2 release.

*There wasn't a PR so I opened this issue.

from: https://github.com/cilium/tetragon/commit/4de6d5458e9a370d1113924276d6c96810465d37 to: https://github.com/cilium/tetragon/commit/ea1fdd60f52370fb5dfd0b189d64ae4061945ab0

Tetragon Version

0.11.0

Kernel Version

NA

Kubernetes Version

No response

Bugtool

No response

Relevant log output

No response

Anything else?

No response

[mtardy]

Indeed, I changed the behavior so that tetragon version is by default tetragon version --client. The old behavior is now tetragon version --server. I wasn't aware that this was related to cilium CLI, what's the incompatibility issue exactly?

[lucasfcnunes]

@mtardy Cilium has too the cilium version --client command.

Current behavior (after https://github.com/cilium/tetragon/commit/ea1fdd60f52370fb5dfd0b189d64ae4061945ab0):

# implicit (odd one and the cause of this issue)
cilium version          # server
tetra version           # client
# explicit
cilium version --client # client
tetra version --server  # server

[kkourt]

The fact that we ended up with a different behavior that the cilium CLI is unfortunate, but I'm not sure that it is a bug.

@lucasfcnunes is there a practical reason that for tetra to be consistent with the cilium cli? Feel free to submit a PR that addresses this.

[lucasfcnunes]

@kkourt I agree it's not a real bug. Guess I should've opened it as a blank issue. I opened this to try to reverse it on tetra v0 or change it in future cilium releases (v1 -> v2). This broke one of my CI/CD scripts so I thought of bringing it up to debate. The practical reason is having to guess how it all works. I personally only check for client version and I think the current behavior of tetra v0.11.0 is better and intuitive.

[kkourt]

@kkourt I agree it's not a real bug. Guess I should've opened it as a blank issue.

No worries, I just wanted to explain why I removed the label.

I opened this to try to reverse it on tetra v0 or change it in future cilium releases (v1 -> v2). This broke one of my CI/CD scripts so I thought of bringing it up to debate. The practical reason is having to guess how it all works. I personally only check for client version and I think the current behavior of tetra v0.11.0 is better and intuitive.

Thanks! FWIW, I don't have a strong opinion on the matter. For some context, my motivation for having both the client and the server version (in the old version) was to spot incompatibilities between client/server versions.

We have no guarantees for the stability of the tetra CLI, but we should maybe be more careful about introducing breaking changes in the future if we can avoid it.