Fix rkt volumes

CHANGELOG.md

@@ -1,11 +1,15 @@
 ## 0.5.1 (Unreleased)
 
+IMPROVEMENTS:
+  * driver/rkt: Support rkt's `--dns=host` and `--dns=none` options [GH-2028]
+
 BUG FIXES:
   * agent/config: Fix use of IPv6 addresses [GH-2036]
   * cli: Improve parsing error when a job without a name is specified [GH-2030]
   * client: Fix race on StreamFramer Destroy which would cause a panic [GH-2007]
   * driver/docker: Make container exist errors non-retriable by task runner
     [GH-2033]
+  * driver/rkt: Fix validation of rkt volumes [GH-2027]
 
 ## 0.5.0 (November 16, 2016)
 

client/driver/rkt.go

@@ -136,6 +136,9 @@ func (d *RktDriver) Validate(config map[string]interface{}) error {
 			"debug": &fields.FieldSchema{
 				Type: fields.TypeBool,
 			},
+			"volumes": &fields.FieldSchema{
+				Type: fields.TypeArray,
+			},
 		},
 	}
 
@@ -306,13 +309,18 @@ func (d *RktDriver) Start(ctx *ExecContext, task *structs.Task) (DriverHandle, e
 	cmdArgs = append(cmdArgs, fmt.Sprintf("--cpu=%vm", int64(task.Resources.CPU)))
 
 	// Add DNS servers
-	for _, ip := range driverConfig.DNSServers {
-		if err := net.ParseIP(ip); err == nil {
-			msg := fmt.Errorf("invalid ip address for container dns server %q", ip)
-			d.logger.Printf("[DEBUG] driver.rkt: %v", msg)
-			return nil, msg
-		} else {
-			cmdArgs = append(cmdArgs, fmt.Sprintf("--dns=%s", ip))
+	if len(driverConfig.DNSServers) == 1 && (driverConfig.DNSServers[0] == "host" || driverConfig.DNSServers[0] == "none") {
+		// Special case single item lists with the special values "host" or "none"
+		cmdArgs = append(cmdArgs, fmt.Sprintf("--dns=%s", driverConfig.DNSServers[0]))
+	} else {
+		for _, ip := range driverConfig.DNSServers {
+			if err := net.ParseIP(ip); err == nil {
+				msg := fmt.Errorf("invalid ip address for container dns server %q", ip)
+				d.logger.Printf("[DEBUG] driver.rkt: %v", msg)
+				return nil, msg
+			} else {
+				cmdArgs = append(cmdArgs, fmt.Sprintf("--dns=%s", ip))
+			}
 		}
 	}