From bd6b7ad1623084cee83fe1423c11c7db8680ab02 Mon Sep 17 00:00:00 2001
From: Kyle Havlovitz <kylehav@gmail.com>
Date: Sun, 2 Dec 2018 23:11:48 -0800
Subject: [PATCH] txn: add pre-check operations to txn endpoint

---
 agent/consul/catalog_endpoint.go | 11 ++++++++---
 agent/consul/state/catalog.go    |  2 +-
 agent/consul/txn_endpoint.go     |  5 ++++-
 3 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/agent/consul/catalog_endpoint.go b/agent/consul/catalog_endpoint.go
index da13abf6c..447a6f38f 100644
--- a/agent/consul/catalog_endpoint.go
+++ b/agent/consul/catalog_endpoint.go
@@ -20,6 +20,13 @@ type Catalog struct {
 	srv *Server
 }
 
+// checkPreApply does the verification of a check before it is applied to Raft.
+func checkPreApply(check *structs.HealthCheck) {
+	if check.CheckID == "" && check.Name != "" {
+		check.CheckID = types.CheckID(check.Name)
+	}
+}
+
 // Register is used register that a node is providing a given service.
 func (c *Catalog) Register(args *structs.RegisterRequest, reply *struct{}) error {
 	if done, err := c.srv.forward("Catalog.Register", args, args, reply); done {
@@ -96,12 +103,10 @@ func (c *Catalog) Register(args *structs.RegisterRequest, reply *struct{}) error
 		args.Check = nil
 	}
 	for _, check := range args.Checks {
-		if check.CheckID == "" && check.Name != "" {
-			check.CheckID = types.CheckID(check.Name)
-		}
 		if check.Node == "" {
 			check.Node = args.Node
 		}
+		checkPreApply(check)
 	}
 
 	// Check the complete register request against the given ACL policy.
diff --git a/agent/consul/state/catalog.go b/agent/consul/state/catalog.go
index 1114cd2e3..89d21a267 100644
--- a/agent/consul/state/catalog.go
+++ b/agent/consul/state/catalog.go
@@ -1592,7 +1592,7 @@ func (s *Store) DeleteCheck(idx uint64, node string, checkID types.CheckID) erro
 }
 
 // deleteCheckCASTxn is used to try doing a check delete operation with a given
-// raft index. If the CAS index specified is not equal to the last bserved index for
+// raft index. If the CAS index specified is not equal to the last observed index for
 // the given check, then the call is a noop, otherwise a normal check delete is invoked.
 func (s *Store) deleteCheckCASTxn(tx *memdb.Txn, idx, cidx uint64, node string, checkID types.CheckID) (bool, error) {
 	// Try to retrieve the existing health check.
diff --git a/agent/consul/txn_endpoint.go b/agent/consul/txn_endpoint.go
index 236d4da9b..785beadf0 100644
--- a/agent/consul/txn_endpoint.go
+++ b/agent/consul/txn_endpoint.go
@@ -21,7 +21,8 @@ func (t *Txn) preCheck(authorizer acl.Authorizer, ops structs.TxnOps) structs.Tx
 
 	// Perform the pre-apply checks for any KV operations.
 	for i, op := range ops {
-		if op.KV != nil {
+		switch {
+		case op.KV != nil:
 			ok, err := kvsPreApply(t.srv, authorizer, op.KV.Verb, &op.KV.DirEnt)
 			if err != nil {
 				errors = append(errors, &structs.TxnError{
@@ -35,6 +36,8 @@ func (t *Txn) preCheck(authorizer acl.Authorizer, ops structs.TxnOps) structs.Tx
 					What:    err.Error(),
 				})
 			}
+		case op.Check != nil:
+			checkPreApply(&op.Check.Check)
 		}
 	}