Get rid of versionInfo based templating. Get rid of versionInfo field from tasks and experiment.spec.

[sriumcp]

Is your feature request related to a problem? Please describe the problem.
Templating in experiment is complicated. Templating based on version specific information takes this complication to a higher level and makes it really complicated.

Describe the feature/solution you'd like
Drop versionInfo based templating. Drop versionInfo field from all tasks and experiment spec. Version info is still required for metrics as described in #942; this is ok since we are not planning to use it for version specific templating within metrics.

Will this feature/solution bring new benefits for Iter8 users? What are they?
Makes experiments less voodoo and more easy to read/write.

Will this feature/solution bring new benefits for Iter8 developers? What are they?

• Makes tutorials less voodoo and more easy to read/write.
• Makes task development less complicated. Templates will not have version-specific variables. They can still interpolate based on experiment-level variables / functions.

Does this issue require a design doc/discussion? If there is a link to the design document/discussions, please provide it below.
Yes, see above. The main disadvantage of this approach is that it can make common/bash tasks and individual metrics longer and repetitive. For common/bash, this may not be such a big disadvantage if it is short to begin with. Enhancements like #954 should make things even more compact. For metrics, we are giving up brevity for the sake of explicitness / ease of understanding. Metrics is one of the harder things for users to get right to begin with; ease of understanding is more important to have here compared to brevity.

As discussed in #941, experiment.spec will now have a versionNames field which is simply a list of version names (strings).

How will this feature be tested?

• Existing tests need to work (and may need to be restructured)

How will this feature be documented?

• iter8.tools documentation to be updated.

[sriumcp]

Note: Please see #942

[sriumcp]

with condition

- if: WinnerFound()
  run: kubectl apply -f https://baseline.com.yaml
- if: not WinnerFound()
  run: kubectl apply -f https://candidate.com.yaml

---

with version info

run: kubectl apply -f https://{{ WinnerOrFirst | manifest }}.com.yaml
versionInfo:
- manifest: baseline
- candidate: candidate

We will start with conditions. We will always have the option of introducing versionInfo as above, through non version-breaking CRD changes.

[sriumcp]

{{ .Name }}
{{ .Namespace }}
{{ .Status.winner.whatever }} # this will fail with template execution error

[sriumcp]

We want Secret method as part of template execution.

# better errors bacause you can customize it within the Secret method
run: git clone https://sriumcp:{{ .Secret 'token' }}@github.com/iter8-tools/myrepo.git

[sriumcp]

go Struct embedding to achieve the above ...

type ExperimentWithSecret struct {
  Experiment
  Secret
}

[kalantar]

An implication of this issue is the use of tasks to get and set weights in tasks. Is that correct? This was described in the now closed issue #941.

[sriumcp]

Yes, this is correct.

We can reopen a separate issue for this task.

[kalantar]

An implication of this issue is the use of tasks to get and set weights in tasks. Is that correct?

Yes, this is correct.

Created issue #970 for this.