refactor(map): use config.get instead of pillar.get

[myii]

We've had some discussions in Slack/IRC/Matrix about moving on from pillar.get to config.get. libtofs.jinja is already using the latter. Selected WIP for this PR since this is something to consider across all formulas. The intention here is to open up the discussion about going forward with this.

CC: @gtmanfred.

[gtmanfred]

i like this, because it allows pulling from grains as well as resolves sdb:// uris, so if someone wants to store the data in sdb, they can.

[daks]

For now, I don't really see the use case for config.get instead of pillar.get. I read that it's to reduce load on busy masters, but I'm still not confronted to this problem.
And today all salt docs and 'litterature' (blog posts, ...) talk about pillar and none talk about anything else, like sdb. So I'm not sure if we already know what will replace pillars and there is no documentation.

In theory this has no impact because config.get also read pillars. But in reality I'm pretty sure that requet will take longer if all your data stays in pillars.

My 2 cents :)

in summary: I'm not opposed to this change even if this subject is still quite obscure for me, and I think we (and users above all) miss information about to do things differently.

[gtmanfred]

The time difference is negligible, since it just does a lookup for the key in the __grains__ __opts__ or __pillar__ object, and bails to the next one if it doesn't find it in the first.

[vutny]

I like config.get.

[daks]

The time difference is negligible, since it just does a lookup for the key in the __grains__ __opts__ or __pillar__ object, and bails to the next one if it doesn't find it in the first.

Good to know @gtmanfred

[myii]

Thanks everyone for your feedback. I've merged this PR.

[saltstack-formulas-travis]

🎉 This PR is included in version 2.0.4 🎉

The release is available on GitHub release

Your semantic-release bot 📦🚀

[myii]

This commit may need to be reverted. config.get and pillar.get aren't 100% interchangeable, for example merge=True isn't available for the former. So if the result of the final config.get is an empty dict, the entire map ends up as an empty dict.

I've tried a workaround using defaults.merge again but I'm running into another problem:

TypeError: Cannot update using non-dict types in dictupdate.update()

Anyone know of how this can be resolved? Or is the only option to return back to pillar.get, for the time being at least?

[myii]

Update: I've been able to find a solution to this by building upon the defaults.merge strategy we used to use earlier on. The problem with this is that this doesn't work for salt-ssh users. So the dilemma:

1. Use config.get via. defaults.merge -- get the benefit but leave salt-ssh behind.
2. Use pillar.get -- works for everyone but limited to pillar only.