Network (Neutron)
Neutron is the Network service for OpenStack. Unlike Nova Networking, Neutron allows you to configure advanced virtual network topologies. An example of this is per-tenant private networks.
Neutron is broken up into the following abstractions: Networks, Subnets and Routers. Each has functionality that mimics the physical layers.
Networks
A network represents a slice of the outside network. Networks contain subnets, and routers to route traffic between different subnets and networks.
Create a Network
Network network = os.networking().network()
.create(Builders.network().name("ext_network").tenantId(tenant.getId()).build());
Querying for Networks
// List the networks which the current tenant has access to
List<? extends Network> networks = os.networking().network().list();
// Get a network by ID
Network network = os.networking().network().get("networkId");
Delete a Network
os.networking().network().delete("networkId");
Subnets
A subnet is a subdivision of an IP Network. The examples below will cover basic subnet management and how we leverage them using OpenStack4j.
Create a Subnet
Subnet subnet = os.networking().subnet().create(Builders.subnet()
.name("MySubnet")
.networkId("networkId")
.tenantId("tenantId")
.addPool("192.168.0.1", "192.168.0.254")
.ipVersion(IPVersionType.V4)
.cidr("192.168.0.0/24")
.build());
Querying for Subnets
// List all subnets which the current authorized tenant has access to
List<? extends Subnet> subnets = os.networking().subnet().list();
// Get a Subnet by ID
Subnet subnet = os.networking().subnet().get("subnetId");
Delete a Subnet
os.networking().subnet().delete("subnetId");
Ports
A port is exactly what you think it is. It mimics a physical port which is tied to a network
and can be allocated a fixed ip from a subnet
.
Create a Port
In the example below we will create a new port and assign it a fixed IP Address from the subnet we defined in the above examples.
Port port = os.networking().port().create(Builders.port()
.name("port-1")
.networkId("networkId")
.fixedIp("192.168.0.101", "subnetId")
.build());
Updating the Port
Port updatedPort = os.networking().port().update(port.builder().name("port-1-1").build());
Querying for Ports
// List all Ports which the current authorized tenant has access to
List<? extends Port> ports = os.networking().port().list();
// Get a Port by ID
Port port = os.networking().port().get("portId");
Delete a Port
os.networking().port().delete("portId");
Routers
For outside networks to access VMs, routers between subnets are needed. Each router has one gateway that is connected to a network and many interfaces that are connected to various subnets. Like a real world physical router, subnets can access machines on other subnets that are connected to the same router. More information about routers can be found at Neutron Concepts
Create a Router
Router router = os.networking().router().create(Builders.router()
.name("ext_net")
.adminStateUp(true)
.externalGateway("networkId")
.route("192.168.0.0/24", "10.20.20.1")
.build());
Update a Router
router = os.networking().router().update(router.toBuilder().name("ext_net2").build());
Toggle Administrative State
Router router = os.networking().router().toggleAdminStateUp("routerId", true);
Attaching / Detaching External Interfaces
// Attach an External Interface
RouterInterface iface = os.networking().router()
.attachInterface("routerId", AttachInterfaceType.SUBNET, "subnetId");
// Detach an External Interface
RouterInterface iface = os.networking().router()
.detachInterface("routerId", "subnetId", null);
Delete a Router
os.networking().router().delete("routerId");
Querying for Routers
List<Router> = os.networking().router().list();
// Get a Router by ID
Router router = os.networking().router().get("routerId");