Advanced Networking and Storage Techniques
This section explores sophisticated Docker networking and storage patterns including custom plugins, software-defined networking, and enterprise-grade storage solutions.
Custom Network Plugins
CNI Plugin Development
// cni-plugin/main.go
package main
import (
"encoding/json"
"fmt"
"net"
"os"
"github.com/containernetworking/cni/pkg/skel"
"github.com/containernetworking/cni/pkg/types"
"github.com/containernetworking/cni/pkg/version"
)
type NetConf struct {
types.NetConf
Bridge string `json:"bridge"`
Subnet string `json:"subnet"`
Gateway string `json:"gateway"`
IPAM struct {
Type string `json:"type"`
Subnet string `json:"subnet"`
} `json:"ipam"`
}
func cmdAdd(args *skel.CmdArgs) error {
conf := NetConf{}
if err := json.Unmarshal(args.StdinData, &conf); err != nil {
return fmt.Errorf("failed to parse network configuration: %v", err)
}
// Create bridge if it doesn't exist
if err := createBridge(conf.Bridge); err != nil {
return fmt.Errorf("failed to create bridge: %v", err)
}
// Allocate IP address
ip, err := allocateIP(conf.Subnet)
if err != nil {
return fmt.Errorf("failed to allocate IP: %v", err)
}
// Create veth pair
hostVeth, containerVeth, err := createVethPair(args.ContainerID)
if err != nil {
return fmt.Errorf("failed to create veth pair: %v", err)
}
// Attach host veth to bridge
if err := attachToBridge(hostVeth, conf.Bridge); err != nil {
return fmt.Errorf("failed to attach to bridge: %v", err)
}
// Move container veth to container namespace
if err := moveToNamespace(containerVeth, args.Netns); err != nil {
return fmt.Errorf("failed to move to namespace: %v", err)
}
// Configure container interface
if err := configureInterface(containerVeth, ip, conf.Gateway, args.Netns); err != nil {
return fmt.Errorf("failed to configure interface: %v", err)
}
// Return result
result := &types.Result{
IP4: &types.IPConfig{
IP: net.IPNet{IP: ip, Mask: net.CIDRMask(24, 32)},
Gateway: net.ParseIP(conf.Gateway),
},
}
return result.Print()
}
func cmdDel(args *skel.CmdArgs) error {
// Cleanup network resources
return deleteVethPair(args.ContainerID)
}
func main() {
skel.PluginMain(cmdAdd, cmdDel, version.All)
}
// Helper functions
func createBridge(name string) error {
// Implementation for bridge creation
return nil
}
func allocateIP(subnet string) (net.IP, error) {
// Implementation for IP allocation
return net.ParseIP("192.168.1.100"), nil
}
func createVethPair(containerID string) (string, string, error) {
// Implementation for veth pair creation
hostVeth := fmt.Sprintf("veth%s", containerID[:8])
containerVeth := fmt.Sprintf("eth%s", containerID[:8])
return hostVeth, containerVeth, nil
}
func attachToBridge(veth, bridge string) error {
// Implementation for bridge attachment
return nil
}
func moveToNamespace(veth, netns string) error {
// Implementation for namespace movement
return nil
}
func configureInterface(iface string, ip net.IP, gateway string, netns string) error {
// Implementation for interface configuration
return nil
}
func deleteVethPair(containerID string) error {
// Implementation for cleanup
return nil
}
Docker Network Plugin
// docker-plugin/main.go
package main
import (
"encoding/json"
"fmt"
"net/http"
"github.com/docker/go-plugins-helpers/network"
)
type CustomDriver struct {
networks map[string]*NetworkState
}
type NetworkState struct {
ID string
Name string
Subnet string
Gateway string
Bridge string
}
func (d *CustomDriver) GetCapabilities() (*network.CapabilitiesResponse, error) {
return &network.CapabilitiesResponse{
Scope: network.LocalScope,
ConnectivityScope: network.LocalScope,
}, nil
}
func (d *CustomDriver) CreateNetwork(req *network.CreateNetworkRequest) error {
// Parse network options
subnet := req.Options["subnet"]
gateway := req.Options["gateway"]
bridge := fmt.Sprintf("br-%s", req.NetworkID[:12])
// Create network state
d.networks[req.NetworkID] = &NetworkState{
ID: req.NetworkID,
Name: req.NetworkID,
Subnet: subnet,
Gateway: gateway,
Bridge: bridge,
}
// Create actual network infrastructure
return d.createNetworkInfrastructure(d.networks[req.NetworkID])
}
func (d *CustomDriver) DeleteNetwork(req *network.DeleteNetworkRequest) error {
state, exists := d.networks[req.NetworkID]
if !exists {
return fmt.Errorf("network %s not found", req.NetworkID)
}
// Cleanup network infrastructure
if err := d.deleteNetworkInfrastructure(state); err != nil {
return err
}
delete(d.networks, req.NetworkID)
return nil
}
func (d *CustomDriver) CreateEndpoint(req *network.CreateEndpointRequest) (*network.CreateEndpointResponse, error) {
state := d.networks[req.NetworkID]
// Create endpoint (veth pair, IP allocation, etc.)
ip, err := d.allocateIP(state.Subnet)
if err != nil {
return nil, err
}
return &network.CreateEndpointResponse{
Interface: &network.EndpointInterface{
Address: ip,
MacAddress: generateMAC(),
},
}, nil
}
func (d *CustomDriver) Join(req *network.JoinRequest) (*network.JoinResponse, error) {
state := d.networks[req.NetworkID]
// Create veth pair and configure
hostVeth, containerVeth, err := d.createVethPair(req.EndpointID)
if err != nil {
return nil, err
}
// Attach to bridge
if err := d.attachToBridge(hostVeth, state.Bridge); err != nil {
return nil, err
}
return &network.JoinResponse{
InterfaceName: network.InterfaceName{
SrcName: containerVeth,
DstPrefix: "eth",
},
Gateway: state.Gateway,
}, nil
}
func (d *CustomDriver) Leave(req *network.LeaveRequest) error {
// Cleanup endpoint resources
return d.deleteVethPair(req.EndpointID)
}
func (d *CustomDriver) DeleteEndpoint(req *network.DeleteEndpointRequest) error {
// Cleanup endpoint state
return nil
}
func main() {
driver := &CustomDriver{
networks: make(map[string]*NetworkState),
}
handler := network.NewHandler(driver)
http.ListenAndServe(":8080", handler)
}
// Helper methods
func (d *CustomDriver) createNetworkInfrastructure(state *NetworkState) error {
// Implementation for creating bridges, iptables rules, etc.
return nil
}
func (d *CustomDriver) deleteNetworkInfrastructure(state *NetworkState) error {
// Implementation for cleanup
return nil
}
func (d *CustomDriver) allocateIP(subnet string) (string, error) {
// Implementation for IP allocation
return "192.168.1.100/24", nil
}
func (d *CustomDriver) createVethPair(endpointID string) (string, string, error) {
// Implementation for veth pair creation
return "veth" + endpointID[:8], "eth" + endpointID[:8], nil
}
func (d *CustomDriver) attachToBridge(veth, bridge string) error {
// Implementation for bridge attachment
return nil
}
func (d *CustomDriver) deleteVethPair(endpointID string) error {
// Implementation for cleanup
return nil
}
func generateMAC() string {
// Implementation for MAC address generation
return "02:42:ac:11:00:02"
}
Software-Defined Networking
OpenVSwitch Integration
# docker-compose.ovs.yml
version: '3.8'
services:
# OpenVSwitch Database
ovs-db:
image: openvswitch/ovs:latest
privileged: true
networks:
- ovs-control
volumes:
- ovs-db-data:/var/lib/openvswitch
- /sys/fs/cgroup:/sys/fs/cgroup:ro
command: |
sh -c "
ovsdb-server --remote=punix:/var/run/openvswitch/db.sock \
--remote=db:Open_vSwitch,Open_vSwitch,manager_options \
--pidfile --detach
ovs-vsctl --no-wait init
tail -f /dev/null
"
# OpenVSwitch Daemon
ovs-vswitchd:
image: openvswitch/ovs:latest
privileged: true
networks:
- ovs-control
volumes:
- ovs-db-data:/var/lib/openvswitch
- /sys/fs/cgroup:/sys/fs/cgroup:ro
depends_on:
- ovs-db
command: |
sh -c "
ovs-vswitchd --pidfile --detach
tail -f /dev/null
"
# SDN Controller (Floodlight)
sdn-controller:
image: floodlight/floodlight:latest
ports:
- "8080:8080"
- "6653:6653"
networks:
- ovs-control
volumes:
- ./floodlight/floodlightdefault.properties:/opt/floodlight/src/main/resources/floodlightdefault.properties:ro
# Application containers using OVS
app1:
image: alpine
networks:
- ovs-network
command: sleep 3600
app2:
image: alpine
networks:
- ovs-network
command: sleep 3600
networks:
ovs-control:
driver: bridge
ovs-network:
driver: ovs
driver_opts:
ovs.bridge.name: br-ovs
ovs.bridge.controller: tcp:sdn-controller:6653
volumes:
ovs-db-data:
Network Function Virtualization
# docker-compose.nfv.yml
version: '3.8'
services:
# Virtual Firewall
virtual-firewall:
build: ./nfv/firewall
privileged: true
networks:
- nfv-mgmt
- nfv-data
volumes:
- ./firewall/rules.conf:/etc/firewall/rules.conf:ro
environment:
- INTERFACES=eth0,eth1
- RULES_FILE=/etc/firewall/rules.conf
# Virtual Load Balancer
virtual-lb:
build: ./nfv/loadbalancer
networks:
- nfv-mgmt
- nfv-data
volumes:
- ./lb/haproxy.cfg:/etc/haproxy/haproxy.cfg:ro
ports:
- "80:80"
- "443:443"
# Virtual Router
virtual-router:
build: ./nfv/router
privileged: true
networks:
- nfv-mgmt
- nfv-data
- external
volumes:
- ./router/quagga.conf:/etc/quagga/quagga.conf:ro
sysctls:
- net.ipv4.ip_forward=1
# Network Monitoring
network-monitor:
image: prom/prometheus
networks:
- nfv-mgmt
volumes:
- ./monitoring/prometheus.yml:/etc/prometheus/prometheus.yml:ro
- prometheus-data:/prometheus
# Service Orchestrator
nfv-orchestrator:
build: ./nfv/orchestrator
networks:
- nfv-mgmt
volumes:
- /var/run/docker.sock:/var/run/docker.sock
- ./orchestrator/config.yaml:/etc/orchestrator/config.yaml:ro
environment:
- DOCKER_HOST=unix:///var/run/docker.sock
networks:
nfv-mgmt:
driver: bridge
ipam:
config:
- subnet: 10.0.1.0/24
nfv-data:
driver: bridge
ipam:
config:
- subnet: 10.0.2.0/24
external:
driver: bridge
volumes:
prometheus-data:
Advanced Storage Drivers
Custom Storage Plugin
// storage-plugin/main.go
package main
import (
"encoding/json"
"fmt"
"net/http"
"os"
"path/filepath"
"github.com/docker/go-plugins-helpers/volume"
)
type CustomVolumeDriver struct {
volumes map[string]*VolumeState
root string
}
type VolumeState struct {
Name string
Path string
Options map[string]string
Mountpoint string
}
func (d *CustomVolumeDriver) Create(req *volume.CreateRequest) error {
// Parse options
volumeType := req.Options["type"]
size := req.Options["size"]
encryption := req.Options["encryption"]
// Create volume directory
volumePath := filepath.Join(d.root, req.Name)
if err := os.MkdirAll(volumePath, 0755); err != nil {
return err
}
// Apply volume-specific configuration
switch volumeType {
case "encrypted":
if err := d.setupEncryption(volumePath, encryption); err != nil {
return err
}
case "compressed":
if err := d.setupCompression(volumePath); err != nil {
return err
}
case "replicated":
if err := d.setupReplication(volumePath, req.Options); err != nil {
return err
}
}
// Store volume state
d.volumes[req.Name] = &VolumeState{
Name: req.Name,
Path: volumePath,
Options: req.Options,
}
return nil
}
func (d *CustomVolumeDriver) Remove(req *volume.RemoveRequest) error {
state, exists := d.volumes[req.Name]
if !exists {
return fmt.Errorf("volume %s not found", req.Name)
}
// Cleanup volume resources
if err := d.cleanupVolume(state); err != nil {
return err
}
// Remove directory
if err := os.RemoveAll(state.Path); err != nil {
return err
}
delete(d.volumes, req.Name)
return nil
}
func (d *CustomVolumeDriver) Mount(req *volume.MountRequest) (*volume.MountResponse, error) {
state, exists := d.volumes[req.Name]
if !exists {
return nil, fmt.Errorf("volume %s not found", req.Name)
}
// Prepare mount point
mountpoint := filepath.Join("/mnt", req.Name)
if err := os.MkdirAll(mountpoint, 0755); err != nil {
return nil, err
}
// Mount based on volume type
if err := d.mountVolume(state, mountpoint); err != nil {
return nil, err
}
state.Mountpoint = mountpoint
return &volume.MountResponse{Mountpoint: mountpoint}, nil
}
func (d *CustomVolumeDriver) Unmount(req *volume.UnmountRequest) error {
state, exists := d.volumes[req.Name]
if !exists {
return fmt.Errorf("volume %s not found", req.Name)
}
// Unmount volume
if err := d.unmountVolume(state); err != nil {
return err
}
state.Mountpoint = ""
return nil
}
func (d *CustomVolumeDriver) Path(req *volume.PathRequest) (*volume.PathResponse, error) {
state, exists := d.volumes[req.Name]
if !exists {
return nil, fmt.Errorf("volume %s not found", req.Name)
}
return &volume.PathResponse{Mountpoint: state.Mountpoint}, nil
}
func (d *CustomVolumeDriver) Get(req *volume.GetRequest) (*volume.GetResponse, error) {
state, exists := d.volumes[req.Name]
if !exists {
return nil, fmt.Errorf("volume %s not found", req.Name)
}
return &volume.GetResponse{
Volume: &volume.Volume{
Name: state.Name,
Mountpoint: state.Mountpoint,
},
}, nil
}
func (d *CustomVolumeDriver) List() (*volume.ListResponse, error) {
var volumes []*volume.Volume
for _, state := range d.volumes {
volumes = append(volumes, &volume.Volume{
Name: state.Name,
Mountpoint: state.Mountpoint,
})
}
return &volume.ListResponse{Volumes: volumes}, nil
}
func (d *CustomVolumeDriver) Capabilities() *volume.CapabilitiesResponse {
return &volume.CapabilitiesResponse{
Capabilities: volume.Capability{Scope: "local"},
}
}
// Helper methods
func (d *CustomVolumeDriver) setupEncryption(path, algorithm string) error {
// Implementation for encryption setup
return nil
}
func (d *CustomVolumeDriver) setupCompression(path string) error {
// Implementation for compression setup
return nil
}
func (d *CustomVolumeDriver) setupReplication(path string, options map[string]string) error {
// Implementation for replication setup
return nil
}
func (d *CustomVolumeDriver) cleanupVolume(state *VolumeState) error {
// Implementation for volume cleanup
return nil
}
func (d *CustomVolumeDriver) mountVolume(state *VolumeState, mountpoint string) error {
// Implementation for volume mounting
return nil
}
func (d *CustomVolumeDriver) unmountVolume(state *VolumeState) error {
// Implementation for volume unmounting
return nil
}
func main() {
driver := &CustomVolumeDriver{
volumes: make(map[string]*VolumeState),
root: "/var/lib/custom-volumes",
}
handler := volume.NewHandler(driver)
http.ListenAndServe(":8080", handler)
}
Container Storage Interface (CSI)
CSI Driver Implementation
// csi-driver/main.go
package main
import (
"context"
"fmt"
"net"
"github.com/container-storage-interface/spec/lib/go/csi"
"google.golang.org/grpc"
)
type CSIDriver struct {
name string
version string
nodeID string
}
// Identity Service
func (d *CSIDriver) GetPluginInfo(ctx context.Context, req *csi.GetPluginInfoRequest) (*csi.GetPluginInfoResponse, error) {
return &csi.GetPluginInfoResponse{
Name: d.name,
VendorVersion: d.version,
}, nil
}
func (d *CSIDriver) GetPluginCapabilities(ctx context.Context, req *csi.GetPluginCapabilitiesRequest) (*csi.GetPluginCapabilitiesResponse, error) {
return &csi.GetPluginCapabilitiesResponse{
Capabilities: []*csi.PluginCapability{
{
Type: &csi.PluginCapability_Service_{
Service: &csi.PluginCapability_Service{
Type: csi.PluginCapability_Service_CONTROLLER_SERVICE,
},
},
},
},
}, nil
}
func (d *CSIDriver) Probe(ctx context.Context, req *csi.ProbeRequest) (*csi.ProbeResponse, error) {
return &csi.ProbeResponse{}, nil
}
// Controller Service
func (d *CSIDriver) CreateVolume(ctx context.Context, req *csi.CreateVolumeRequest) (*csi.CreateVolumeResponse, error) {
volumeID := generateVolumeID()
// Create volume based on parameters
parameters := req.GetParameters()
volumeType := parameters["type"]
size := req.GetCapacityRange().GetRequiredBytes()
volume, err := d.createVolumeBackend(volumeID, volumeType, size, parameters)
if err != nil {
return nil, err
}
return &csi.CreateVolumeResponse{
Volume: &csi.Volume{
VolumeId: volumeID,
CapacityBytes: size,
VolumeContext: volume.Context,
},
}, nil
}
func (d *CSIDriver) DeleteVolume(ctx context.Context, req *csi.DeleteVolumeRequest) (*csi.DeleteVolumeResponse, error) {
volumeID := req.GetVolumeId()
if err := d.deleteVolumeBackend(volumeID); err != nil {
return nil, err
}
return &csi.DeleteVolumeResponse{}, nil
}
func (d *CSIDriver) ControllerPublishVolume(ctx context.Context, req *csi.ControllerPublishVolumeRequest) (*csi.ControllerPublishVolumeResponse, error) {
volumeID := req.GetVolumeId()
nodeID := req.GetNodeId()
publishContext, err := d.attachVolumeToNode(volumeID, nodeID)
if err != nil {
return nil, err
}
return &csi.ControllerPublishVolumeResponse{
PublishContext: publishContext,
}, nil
}
// Node Service
func (d *CSIDriver) NodeStageVolume(ctx context.Context, req *csi.NodeStageVolumeRequest) (*csi.NodeStageVolumeResponse, error) {
volumeID := req.GetVolumeId()
stagingPath := req.GetStagingTargetPath()
if err := d.stageVolume(volumeID, stagingPath, req.GetPublishContext()); err != nil {
return nil, err
}
return &csi.NodeStageVolumeResponse{}, nil
}
func (d *CSIDriver) NodePublishVolume(ctx context.Context, req *csi.NodePublishVolumeRequest) (*csi.NodePublishVolumeResponse, error) {
volumeID := req.GetVolumeId()
targetPath := req.GetTargetPath()
stagingPath := req.GetStagingTargetPath()
if err := d.publishVolume(volumeID, stagingPath, targetPath); err != nil {
return nil, err
}
return &csi.NodePublishVolumeResponse{}, nil
}
func (d *CSIDriver) NodeGetCapabilities(ctx context.Context, req *csi.NodeGetCapabilitiesRequest) (*csi.NodeGetCapabilitiesResponse, error) {
return &csi.NodeGetCapabilitiesResponse{
Capabilities: []*csi.NodeServiceCapability{
{
Type: &csi.NodeServiceCapability_Rpc{
Rpc: &csi.NodeServiceCapability_RPC{
Type: csi.NodeServiceCapability_RPC_STAGE_UNSTAGE_VOLUME,
},
},
},
},
}, nil
}
func (d *CSIDriver) NodeGetInfo(ctx context.Context, req *csi.NodeGetInfoRequest) (*csi.NodeGetInfoResponse, error) {
return &csi.NodeGetInfoResponse{
NodeId: d.nodeID,
}, nil
}
// Helper methods
func (d *CSIDriver) createVolumeBackend(volumeID, volumeType string, size int64, parameters map[string]string) (*VolumeInfo, error) {
// Implementation for volume creation
return &VolumeInfo{
ID: volumeID,
Context: map[string]string{"type": volumeType},
}, nil
}
func (d *CSIDriver) deleteVolumeBackend(volumeID string) error {
// Implementation for volume deletion
return nil
}
func (d *CSIDriver) attachVolumeToNode(volumeID, nodeID string) (map[string]string, error) {
// Implementation for volume attachment
return map[string]string{"device": "/dev/sdb"}, nil
}
func (d *CSIDriver) stageVolume(volumeID, stagingPath string, publishContext map[string]string) error {
// Implementation for volume staging
return nil
}
func (d *CSIDriver) publishVolume(volumeID, stagingPath, targetPath string) error {
// Implementation for volume publishing
return nil
}
type VolumeInfo struct {
ID string
Context map[string]string
}
func generateVolumeID() string {
return fmt.Sprintf("vol-%d", time.Now().Unix())
}
func main() {
driver := &CSIDriver{
name: "custom.csi.driver",
version: "1.0.0",
nodeID: "node-1",
}
listener, err := net.Listen("unix", "/tmp/csi.sock")
if err != nil {
panic(err)
}
server := grpc.NewServer()
csi.RegisterIdentityServer(server, driver)
csi.RegisterControllerServer(server, driver)
csi.RegisterNodeServer(server, driver)
server.Serve(listener)
}
Summary
This section covered advanced networking and storage techniques:
Custom Network Solutions
- CNI Plugins: Container Network Interface plugin development
- Docker Network Plugins: Custom network drivers for Docker
- Software-Defined Networking: OpenVSwitch and SDN controller integration
- Network Function Virtualization: Virtual firewalls, load balancers, and routers
Advanced Storage Systems
- Custom Volume Drivers: Docker volume plugin development with encryption and replication
- CSI Implementation: Container Storage Interface driver for Kubernetes integration
- Storage Orchestration: Automated storage provisioning and management
Enterprise Patterns
- Plugin Architecture: Extensible networking and storage solutions
- Service Orchestration: Automated network function deployment
- Performance Optimization: Advanced tuning and monitoring capabilities
- Security Integration: Encryption, access control, and compliance features
Next Steps: Part 5 demonstrates complete production implementations combining all these advanced techniques into enterprise-ready networking and storage solutions.