Block deployment if the driver is configured to use a RedHat 6 or 7 OS image (#6).

Author: tintoy

README.md

@@ -40,7 +40,7 @@ Environment: `MCP_REGION`.
 * `ddcloud-vlan` - The name of the target CloudControl VLAN.
 * `ddcloud-image-name` - The name of the OS image used to create the target machine.  
 Note that only OS images are supported for now, not customer images.  
-Additionally, the OS must be a Linux distribution supported by docker-machine (Ubuntu 14.04 and above work, but Red Hat 7 has issues due to iptables configuration).
+Additionally, the OS must be a Linux distribution supported by docker-machine (Ubuntu 12.04 and above are supported, but RedHat 6 and 7 are not supported due to iptables configuration issues).
 * `ddcloud-ssh-user` - The SSH username to use.  
 Default: "root".  
 Environment: `MCP_SSH_USER`

driver.go

@@ -233,12 +233,9 @@ func (driver *Driver) PreCreateCheck() error {
 	switch driver.ImageOSType {
 	case "REDHAT664":
 	case "REDHAT764":
-		log.Warnf("Image '%s' is RedHat 6 or 7 (64-bit).",
+		return fmt.Errorf("Image '%s' is not currently supported because the CloudControl images based on RedHat 6 and 7 are known to have problems with Docker Machine.",
 			driver.ImageName,
 		)
-		log.Warnf("This image is known to have problems with Docker Machine (the ddcloud driver will need to clear the server's iptables configuration when it is provisioned).")
-
-		break
 	}
 
 	return nil
@@ -298,17 +295,6 @@ func (driver *Driver) Create() error {
 		return err
 	}
 
-	switch driver.ImageOSType {
-	case "REDHAT664":
-	case "REDHAT764":
-		err = driver.clearIPTablesConfiguration()
-		if err != nil {
-			return err
-		}
-
-		break
-	}
-
 	log.Infof("Server '%s' has been successfully created.", server.Name)
 
 	return nil