3 ms·

While this is a very welcome improvement in terms of functionality, I can't help by feel that the re-use of "restartPolicy" to mean something similar, but diffe

While this is a very welcome improvement in terms of functionality, I can't help by feel that the re-use of "restartPolicy" to mean something similar, but different, when used in a different context, is a very poor decision. Kubernetes already has an issue with having a (perceived) high barrier to entry, and I'm not sure that "restartPolicy on a container means this, unless isn't used in this list of containers, in which case it means this". I would have preferred to see a separate attribute (such as `sidecar: true`), rather than overloading (and in my opinion, abusing) the existing `restartPolicy`.

deleted 3y ago
[deleted]
0xbadcafebee 3y ago
It's par for the course. Most of K8s's design has been shoving whatever crap they feel like in, regardless of confusion, difficulty, complexity, etc for the end user.
- perryizgr8 3y ago
  At some level it seems deliberate so that administration of the complexity can be sold to you for a price once you realise that you can't hack it on your own, but are now too invested to back out.
smarterclayton 3y ago
The challenge with a separate attribute is that it is not forward compatible with new features we might add to pods around ordering and lifecycle. If we used a simple boolean, eventually we’d have to have it interact with other fields and deal with conflicting behaviors between what “sidecar” means and more flexibility. The only difference today between init containers and regular containers is: a) init containers have an implicit default restart policy of OnFailure, and regular containers inherit the pods restartPolicy b) init containers are serial, regular containers are parallel We are leaving room for the possibility that init containers can fail the pod, and be parallelized, as well as regular containers having unique restartPolicies. Both of those would allow more control for workflow / job engines to break apart monolith containers and get better isolation. The key design point was that “sidecars aren’t special containers” - because we want to leave room for future growth.
c7DJTLrn 3y ago
I've been brushing up on my Kubernetes knowledge recently and came across so much gross stuff like this. "If field X is set to Y, then value Z for key V is invalid." Jesus christ. I wish they put more effort into approachability.

deleted 3y ago

[deleted]

0xbadcafebee 3y ago

It's par for the course. Most of K8s's design has been shoving whatever crap they feel like in, regardless of confusion, difficulty, complexity, etc for the end user.

perryizgr8 3y ago
At some level it seems deliberate so that administration of the complexity can be sold to you for a price once you realise that you can't hack it on your own, but are now too invested to back out.

smarterclayton 3y ago

The challenge with a separate attribute is that it is not forward compatible with new features we might add to pods around ordering and lifecycle. If we used a simple boolean, eventually we’d have to have it interact with other fields and deal with conflicting behaviors between what “sidecar” means and more flexibility. The only difference today between init containers and regular containers is: a) init containers have an implicit default restart policy of OnFailure, and regular containers inherit the pods restartPolicy b) init containers are serial, regular containers are parallel We are leaving room for the possibility that init containers can fail the pod, and be parallelized, as well as regular containers having unique restartPolicies. Both of those would allow more control for workflow / job engines to break apart monolith containers and get better isolation. The key design point was that “sidecars aren’t special containers” - because we want to leave room for future growth.

c7DJTLrn 3y ago

I've been brushing up on my Kubernetes knowledge recently and came across so much gross stuff like this. "If field X is set to Y, then value Z for key V is invalid." Jesus christ. I wish they put more effort into approachability.