net

Documentation

Index

• Constants
• func EnableForwarding() error
• func EnsurePodMasq(ipt iptables.Interface, mainNic, podIP string) error
• func GetPrimaryNetworkInterface() (string, error)
• func SetupNetNamespace(podIP string) (string, string, string, error)
• type NetNamespacer
  • func NewNoopNetNamespacer() NetNamespacer
  • func NewOSNetNamespacer(nsname string) NetNamespacer
• type NoopNetNamespacer
  • func (n *NoopNetNamespacer) Create() error
  • func (n *NoopNetNamespacer) CreateVeth(ipaddr string) error
  • func (n *NoopNetNamespacer) WithNetNamespace(cb func() error) error
• type OSNetNamespacer
  • func (n *OSNetNamespacer) Create() error
  • func (n *OSNetNamespacer) CreateVeth(ipaddr string) error
  • func (n *OSNetNamespacer) WithNetNamespace(cb func() error) error

Constants

const (
	NetnsPath = "/var/run/netns"
	Veth0     = "veth0"
	Veth1     = "veth1"
)

const (
	PodNetNamespaceName = "pod"
)

Functions

func EnableForwarding

func EnableForwarding() error

func EnsurePodMasq

func EnsurePodMasq(ipt iptables.Interface, mainNic, podIP string) error

Enable SNAT so the pod can communicate with the public internet. E.g. if the pod IP is 10.0.30.14:

iptables -t nat -N POD_MASQ_CHAIN
iptables -t nat -A POSTROUTING -j POD_MASQ_CHAIN
iptables -t nat -A POD_MASQ_CHAIN ! -o eth0 -j RETURN
iptables -t nat -A POD_MASQ_CHAIN ! -s 10.0.30.14 -j RETURN
iptables -t nat -A POD_MASQ_CHAIN -d 10.0.0.0/8 -j RETURN
iptables -t nat -A POD_MASQ_CHAIN -d 172.16.0.0/12 -j RETURN
iptables -t nat -A POD_MASQ_CHAIN -d 192.168.0.0/16 -j RETURN
iptables -t nat -A POD_MASQ_CHAIN -j MASQUERADE

func GetPrimaryNetworkInterface

func GetPrimaryNetworkInterface() (string, error)

func SetupNetNamespace

func SetupNetNamespace(podIP string) (string, string, string, error)

Types

type NetNamespacer

type NetNamespacer interface {
	Create() error
	WithNetNamespace(cb func() error) error
	CreateVeth(ipaddr string) error
}

func NewNoopNetNamespacer

func NewNoopNetNamespacer() NetNamespacer

func NewOSNetNamespacer

func NewOSNetNamespacer(nsname string) NetNamespacer

type NoopNetNamespacer

type NoopNetNamespacer struct {
}

func (*NoopNetNamespacer) Create

func (n *NoopNetNamespacer) Create() error

func (*NoopNetNamespacer) CreateVeth

func (n *NoopNetNamespacer) CreateVeth(ipaddr string) error

func (*NoopNetNamespacer) WithNetNamespace

func (n *NoopNetNamespacer) WithNetNamespace(cb func() error) error

type OSNetNamespacer

type OSNetNamespacer struct {
	NSName string
}

func (*OSNetNamespacer) Create

func (n *OSNetNamespacer) Create() error

Start a new net namespace, and ensure it persists via creating a bind mount to it. We use NetnsPath to ensure "ip netns" interoperability, so e.g. "ip netns exec <nsname> ip link ls" will work.

func (*OSNetNamespacer) CreateVeth

func (n *OSNetNamespacer) CreateVeth(ipaddr string) error

Create a veth pair, and move the second one into a net namespace.

func (*OSNetNamespacer) WithNetNamespace

func (n *OSNetNamespacer) WithNetNamespace(cb func() error) error

Change to a net namespace temporarily, call a function, and switch back.