Release.Namespace and Release.Time in charts repo but missing from Helm v3

[mattfarina]

The dev-v3 branch, as of c62a3a4, no longer has .Release.Namespace and .Release.Time available in templates. It appears this was changed in aa859e3 in order to "make template rendering discrete and repeatable".

There are some problems with this.

1. Charts in the charts repo use both of these features. See .Release.Time here and .Release.Namespace here. These charts won't work with Helm v3
2. .Release.Namespace is needed for RBAC. Removing it hinders the ability of a chart to create RBAC config. See the comment on the commit and how it's used in the charts repo. Removal of namespace limits what charts can be used for

This was referenced in #4255 (comment) where @adamreese said it would be added back.

cc @bacongobbler @adamreese

[technosophos]

So .Release.Time is effectively the same as calling now as a template function. And when I looked at the use cases, most might be better served by calling a random function instead. I am in favor of not putting that one back in if we can get away with it.

.Release.Namespace got merged back in on #5737 (as a result of this issue). So basically, if we can decide on .Release.Time, that's all that is left for this issue.

[mattfarina]

There aren't many public uses of .Release.Time from what I can tell. I would suggest:

1. We update the cases in the charts repo to use the template function instead
2. We document the use of the template function instead as part of the 2->3 docs

Once we do those two things we can close this out unless I missed something.

[mattfarina]

@technosophos So... everyone is using .Release.Time.Seconds which is seconds in UTC since the unix epoch. There is no golang format pattern to get this. So, we need a different way to handle this.

If we add a function to sprig there will be many using a version of Helm that doesn't support this. Sadly, lots of people use old helm versions. Not sure if they are using this part of release.

I created Masterminds/sprig#164 to give sprig the ability to do this.

[bacongobbler]

Are there action items we should be addressing for Helm 3, or is this safe to close with the sprig bump?

[bacongobbler]

perhaps this should be closed in favour of #5733 if that's the last action item to close this one out.

[bacongobbler]

closing in favour of #5733.

[KIVagant]

So .Release.Time is effectively the same as calling now as a template function.

@technosophos, but isn't there a risk that now can return 1 second difference if it is called in several templates when Helm is processing them very close to a second end? This tiny difference could result in a deployment that could not be able to find it's pod because a label is +/-1 second different?

Was not the .Release.Time calling time.Now() only once and then every subsequent call would return 100% the same number?

[KIVagant]

Also, is there a way of getting a consistent random value that would work equally through all templates (without writing a new helper and defining variables in global scope)?