Why is it that anytime I use a helm chart I get `[...
# generalc
cool-egg-852
10/17/2019, 7:46 PMWhy is it that anytime I use a helm chart I get
[Can't preview] all chart values must be known ahead of time to generate an accurate preview.c
creamy-potato-29402
10/17/2019, 7:49 PMchanging the chart values could change which resources get created and which don’t
c
cool-egg-852
10/17/2019, 7:49 PMRight. But shouldn’t pulumi run the template and see the result?
c
creamy-potato-29402
10/17/2019, 7:50 PMit can’t run it if you provide computed values
creamy-potato-29402
10/17/2019, 7:50 PMor really any references to any resources’s properties
creamy-potato-29402
10/17/2019, 7:50 PMyou can’t know those before you run the actual update.
c
cool-egg-852
10/17/2019, 7:51 PMIt really renders preview 100% useless for helm charts which is a big issue.
c
creamy-potato-29402
10/17/2019, 7:51 PMI agree.
creamy-potato-29402
10/17/2019, 7:52 PMcc @gorgeous-egg-16927 @microscopic-florist-22719
c
cool-egg-852
10/17/2019, 7:52 PMIn this particular case, I really can’t trust the helm chart as it is, because I believe it’ll cause an issue due to istio. So without the preview, I have to kind of risk it and hope for the best.
cool-egg-852
10/17/2019, 7:53 PMc
creamy-potato-29402
10/17/2019, 8:21 PMa not-great solution is to render the charts ahead of time, or not use any references to the actual properties of other resources
c
cool-egg-852
10/17/2019, 8:23 PMI think that any of the values it would use wouldn’t have an impact on how the chart behaves. Unless you do something like
someResource.someValue == 'something' ? 'value' : 'value2'cool-egg-852
10/17/2019, 8:23 PMBut this goes back to my original thought that preview should have the final values always.
upcool-egg-852
10/17/2019, 8:24 PMWhereas they seem to be separate systems and redo a lot of the same calculations.
m
microscopic-florist-22719
10/17/2019, 8:50 PM
They are separate systems. A preview can’t always generate final values, as many values are not known until resource operations are actually performed. We are working at making previews as accurate as possible, and we also have some work in the pipeline that would allow the operations performed by an update to be constrained by those proposed by a preview.
c
cool-egg-852
10/17/2019, 10:19 PMI get what you are saying. Wasn’t thinking about some scenarios. In most of ours where we run into this issue, they are generally known I think, or easy to figure out.
cool-egg-852
10/17/2019, 10:19 PMJust seems like preview has become less and less useful to the point where it’s rarely useful these days.
w
worried-city-86458
10/19/2019, 12:41 AMI've seen this when I was doing something as simple as passing a namespace resource output into the helm chart namespace parameter. I ended up having to use a constant.
s
stocky-island-3676
11/08/2019, 3:32 PMJust seems like preview has become less and less useful to the point where it’s rarely useful these days.I can second this regarding Helm charts. Even if I’ve just stumbled upon the simple
helm.v2.Chart("a",{namespace: namespace.metadata.name})2 Views