Allow pillar relative includes

[waynew]

What does this PR do?

Implements longstanding request #8875 - allows for pillar relative includes

What issues does this PR fix or reference?

#8875 - there are probably others

Previous Behavior

A leading dot in a pillar include was a nop. If you had a pillar like:

foo/bar/baz.sls

include:
  - .bang

That would not refer to foo/bar/bang.sls, but bang.sls at the pillar root.

New Behavior

Now leading dots in includes refer to relative imports 🎉

Tests written?

Yes

Commits signed with GPG?

Yes

---

I'm operating under the assumption that #52008 will be merged.. forward?

[mchugh19]

Can/should this be added to release notes?

[max-arnold]

@waynew It would be nice if this feature worked exactly as in states, i.e. multiple dots should work too: https://docs.saltstack.com/en/latest/ref/states/include.html#relative-include

include:
  - ..http
  - ...base

Also, no docs at all 😞

[waynew]

@max-arnold Do pillar relative includes work that way?

[max-arnold]

@waynew

Do pillar relative includes work that way?

No, pillar includes do not work that way, but it makes sense to implement because state includes support this, and feature symmetry is generally a good thing. See the states doc I mentioned earlier: https://docs.saltstack.com/en/latest/ref/states/include.html#relative-include

In Salt 2015.8, the ability to include SLS formulas which are relative to the parents of the running SLS formula was added. In order to achieve this, precede the formula name with more than one . (dot). Much like Python's relative import abilities, two or more leading dots represent a relative include of the parent or parents of the current package, with each . representing one level after the first.

[waynew]

Wow, I'm not sure at all what I meant there 🙃

I think it's probably worth creating an issue/feature request. I don't know if it's significant enough to create a SEP, but I agree with the feature symmetry point.

[waynew]

When porting this to master it should be noted that it closes #56186