Add revision to reads in TXN to robustness test and add regression test

[serathius]

What would you like to be added?

Issue #18667 was not detected by robustness test because TXN we generate don't set revision in range. We should fix this gap.

TODO:

• Add randomly adding revision to generating multiTXNOps

  etcd/tests/robustness/traffic/etcd.go

  Lines 301 to 332 in 448fb7e

  	func (c etcdTrafficClient) pickMultiTxnOps() (ops []clientv3.Op) {
  	keys := rand.Perm(c.keyCount)
  	opTypes := make([]model.OperationType, 4)
  	atLeastOnePut := false
  	for i := 0; i < MultiOpTxnOpCount; i++ {
  	opTypes[i] = c.pickOperationType()
  	if opTypes[i] == model.PutOperation {
  	atLeastOnePut = true
  	}
  	}
  	// Ensure at least one put to make operation unique
  	if !atLeastOnePut {
  	opTypes[0] = model.PutOperation
  	}
  	for i, opType := range opTypes {
  	key := c.key(keys[i])
  	switch opType {
  	case model.RangeOperation:
  	ops = append(ops, clientv3.OpGet(key))
  	case model.PutOperation:
  	value := fmt.Sprintf("%d", c.idProvider.NewRequestID())
  	ops = append(ops, clientv3.OpPut(key, value))
  	case model.DeleteOperation:
  	ops = append(ops, clientv3.OpDelete(key))
  	default:
  	panic("unsuported choice type")
  	}
  	}
  	return ops
  	}

• Add regression test make test-robustness-issue18667 like in https://github.com/etcd-io/etcd/pull/17680/files

Note, until fix for #18667 is merged, we cannot enable running this test by default. Might need to make setting revision optional and only run it as regression test, only later enabling it by default.

As discussed on Slack @henrybear327 volunteered to work on it.

Why is this needed?

Cover detect and prevent #18667

[serathius]

Any progress?

[serathius]

ping @henrybear327