Fix CAS operations for put

command/kv_put.go

@@ -92,7 +92,6 @@ func (c *KVPutCommand) Run(args []string) int {
 	httpAddr := HTTPAddrFlag(cmdFlags)
 	datacenter := cmdFlags.String("datacenter", "", "")
 	token := cmdFlags.String("token", "", "")
-	stale := cmdFlags.Bool("stale", false, "")
 	cas := cmdFlags.Bool("cas", false, "")
 	flags := cmdFlags.Uint64("flags", 0, "")
 	modifyIndex := cmdFlags.Uint64("modify-index", 0, "")
@@ -111,11 +110,18 @@ func (c *KVPutCommand) Run(args []string) int {
 		return 1
 	}
 
+	// Session is reauired for release or acquire
 	if (*release || *acquire) && *session == "" {
 		c.Ui.Error("Error! Missing -session (required with -acquire and -release)")
 		return 1
 	}
 
+	// ModifyIndex is required for CAS
+	if *cas && *modifyIndex == 0 {
+		c.Ui.Error("Must specify -modify-index with -cas!")
+		return 1
+	}
+
 	// Create and test the HTTP client
 	conf := api.DefaultConfig()
 	conf.Address = *httpAddr
@@ -141,23 +147,6 @@ func (c *KVPutCommand) Run(args []string) int {
 
 	switch {
 	case *cas:
-		// If the user did not supply a -modify-index, but wants a check-and-set,
-		// grab the current modify index and store that on the key.
-		if pair.ModifyIndex == 0 {
-			currentPair, _, err := client.KV().Get(key, &api.QueryOptions{
-				Datacenter: *datacenter,
-				Token:      *token,
-				AllowStale: *stale,
-			})
-			if err != nil {
-				c.Ui.Error(fmt.Sprintf("Error! Could not get current key: %s", err))
-				return 1
-			}
-			if currentPair != nil {
-				pair.ModifyIndex = currentPair.ModifyIndex
-			}
-		}
-
 		ok, _, err := client.KV().CAS(pair, wo)
 		if err != nil {
 			c.Ui.Error(fmt.Sprintf("Error! Did not write to %s: %s", key, err))

command/kv_put_test.go

@@ -37,6 +37,10 @@ func TestKVPutCommand_Validation(t *testing.T) {
 			[]string{"-release", "foo"},
 			"Missing -session",
 		},
+		"-cas no -modify-index": {
+			[]string{"-cas", "foo"},
+			"Must specify -modify-index",
+		},
 		"no key": {
 			[]string{},
 			"Missing KEY argument",
@@ -224,35 +228,6 @@ func TestKVPutCommand_CAS(t *testing.T) {
 	defer srv.Shutdown()
 	waitForLeader(t, srv.httpAddr)
 
-	ui := new(cli.MockUi)
-	c := &KVPutCommand{Ui: ui}
-
-	args := []string{
-		"-http-addr=" + srv.httpAddr,
-		"-cas",
-		"foo", "a",
-	}
-
-	code := c.Run(args)
-	if code != 0 {
-		t.Fatalf("bad: %d. %#v", code, ui.ErrorWriter.String())
-	}
-
-	data, _, err := client.KV().Get("foo", nil)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	if !bytes.Equal(data.Value, []byte("a")) {
-		t.Errorf("bad: %#v", data.Value)
-	}
-}
-
-func TestKVPutCommand_CASModifyIndex(t *testing.T) {
-	srv, client := testAgentWithAPIClient(t)
-	defer srv.Shutdown()
-	waitForLeader(t, srv.httpAddr)
-
 	// Create the initial pair so it has a ModifyIndex.
 	pair := &api.KVPair{
 		Key:   "foo",

website/source/docs/commands/kv/put.html.markdown.erb

@@ -10,8 +10,8 @@ Command: `consul kv put`
 
 The `kv put` command writes the data to the given path in the key-value store.
 The data can be of any type, but it will be transported as a base64-encoded
-string for safe transport. The client will transparently handle the encoding
-and decoding of these values.
+string for safe transport during reads. The client will transparently handle the
+encoding and decoding of these values.
 
 ## Usage
 
@@ -36,8 +36,7 @@ Usage: `consul kv put [options] KEY [DATA]`
   for their use case. The default value is 0 (no flags).
 
 * `-modify-index=<int>` - Unsigned integer representing the ModifyIndex of the
-  key. This is often combined with the -cas flag, but it can be specified for
-  any key. The default value is 0.
+  key. This is used in combination with the -cas flag.
 
 * `-release` - Forfeit the lock on the key at the givne path. This requires the
   -session flag to be set. The key must be held by the session in order to be
@@ -107,15 +106,6 @@ $ consul kv put -cas -modify-index=456 redis/config/connections 10
 Success! Data written to: redis/config/connections
 ```
 
-It is also possible to have Consul fetch the current ModifyIndex before making
-the query, by omitting the `-modify-index` flag. If the data is changed between
-the initial read and the write, the operation will fail.
-
-```
-$ consul kv put -cas redis/config/connections 10
-Success! Data written to: redis/config/connections
-```
-
 To specify flags on the key, use the `-flags` option. These flags are completely
 controlled by the user: