Walking skeleton pulling strategies

[benoitf]

Description

I noticed that with the sample workspace skeleton, the wsskeleton/che-hello is always pulled

here is a run 10mn after

while Theia image is loaded from the cache (already present on the machine)
both of them are described in plug-ins

Reproduction Steps

Create a workspace with workspace.next plug-ins

[benoitf]

related to #11030

[garagatyi]

I investigated this issue and found out:

• we do not set explicitly pull policy
• if pull policy is not set and image tag is latest: OS uses default policy Always
• if pull policy is not set and image tag is not latest, e.g. nightly: OS uses default policy IfNotPresent

So we need to explicitly set pull policy in sidecar containers to Always

[benoitf]

Can it be a parameter ? instead of Always so I can tweak it do IfNotPresent on demand

When I try locally ws.next if I download each image at each workspace restart I have to wait a very long time with my internet connection.

[garagatyi]

@benoitf sure

[mshaposhnik]

Done in #11536