Added ValidateVSchema

[makinje16]

Signed-off-by: Malcolm Akinje makinje@slack-corp.com

Description

This PR adds in ValidateVSchema. ValidateSchemaShard now uses this method as a helper when includeVSchema is provided to it. This also gives the oppourtunity to validate that a shards schema is equivalent to the vschema in other areas besides the aforementioned method like when we create a resharding workflow.

Related Issue(s)

Checklist

• Tests were added or are not required
• Documentation was added or is not required

Deployment Notes

[ajm188]

Almost there, I think. I think the current refactor makes the ValidateSchemaShard a little overloaded, and pulling out the vschema validation to its own function will make this a bit clearer.

[ajm188]

We should add a flag to this command (and probably ValidateSchemaShard, sorry for not pointing that out earlier) to be able to pass true through here.

[ajm188]

Everything I have is pretty minor changes; I think Rafa was saying he had other thoughts so we should wait for him as well.

[ajm188]

nit: should be false?

[makinje16]

changed 👍

[ajm188]

You shouldn't need to pass a reference to the recorder here; it's in scope in the closure of the goroutine (similar to how you're using the wait group).

[makinje16]

I actually got linting errors when I did not pass in the recorder or shard which is why I passed them in

Linting go/vt/wrangler
go/vt/wrangler/schema.go:289:45: loopclosure: loop variable shard captured by func literal (govet)
			si, err := wr.ts.GetShard(ctx, keyspace, shard)
			                                         ^
go/vt/wrangler/schema.go:291:83: loopclosure: loop variable shard captured by func literal (govet)
				shardFailures.RecordError(fmt.Errorf("GetShard(%v, %v) failed: %v", keyspace, shard, err))
				                                                                              ^
go/vt/wrangler/schema.go:297:45: loopclosure: loop variable shard captured by func literal (govet)
					excludeTables, includeViews, keyspace, shard, err,
					                                       ^

[ajm188]

Those lint errors are complaining about the shard variable specifically (which is a correct error). I'm talking about just the shardFailures variable which isn't part of the range loop.

To illustrate what the linter is warning about, check out the difference between these two loops: https://play.golang.org/p/eQtSzSI60lR

[ajm188]

I think this is unused?

[makinje16]

This is unused currently but thought that this functionality may be needed at some point. Instead of requiring the caller to pass in all shard names to ValidateVSchema we can use this. In the two instances in which I've seen us validate the vschema we also have had the shards we are trying to validate so I understand if we should remove this.

[ajm188]

Yeah I think if we don't need it now (and we don't expect to immediately need it in the short-term), then we should hold off. We can always add it back later!

[ajm188]

unused?

[makinje16]

removed

[rafael]

Thank you for addressing all the comments. This looks good to me.

[ajm188]

looks good to me! thanks Malcolm ❤️