moby/libnetwork/service.go

// FIXME(thaJeztah): remove once we are a module; the go:build directive prevents go from downgrading language version to go1.16:
//go:build go1.19

package libnetwork

import (
	"fmt"
	"net"
	"sync"

	"github.com/docker/docker/libnetwork/internal/setmatrix"
)

var (
	// A global monotonic counter to assign firewall marks to
	// services.
	fwMarkCtr   uint32 = 256
	fwMarkCtrMu sync.Mutex
)

type portConfigs []*PortConfig

func (p portConfigs) String() string {
	if len(p) == 0 {
		return ""
	}

	pc := p[0]
	str := fmt.Sprintf("%d:%d/%s", pc.PublishedPort, pc.TargetPort, PortConfig_Protocol_name[int32(pc.Protocol)])
	for _, pc := range p[1:] {
		str = str + fmt.Sprintf(",%d:%d/%s", pc.PublishedPort, pc.TargetPort, PortConfig_Protocol_name[int32(pc.Protocol)])
	}

	return str
}

type serviceKey struct {
	id    string
	ports string
}

type service struct {
	name string // Service Name
	id   string // Service ID

	// Map of loadbalancers for the service one-per attached
	// network. It is keyed with network ID.
	loadBalancers map[string]*loadBalancer

	// List of ingress ports exposed by the service
	ingressPorts portConfigs

	// Service aliases
	aliases []string

	// This maps tracks for each IP address the list of endpoints ID
	// associated with it. At stable state the endpoint ID expected is 1
	// but during transition and service change it is possible to have
	// temporary more than 1
	ipToEndpoint setmatrix.SetMatrix[string]

	deleted bool

	sync.Mutex
}

// assignIPToEndpoint inserts the mapping between the IP and the endpoint identifier
// returns true if the mapping was not present, false otherwise
// returns also the number of endpoints associated to the IP
func (s *service) assignIPToEndpoint(ip, eID string) (bool, int) {
	return s.ipToEndpoint.Insert(ip, eID)
}

// removeIPToEndpoint removes the mapping between the IP and the endpoint identifier
// returns true if the mapping was deleted, false otherwise
// returns also the number of endpoints associated to the IP
func (s *service) removeIPToEndpoint(ip, eID string) (bool, int) {
	return s.ipToEndpoint.Remove(ip, eID)
}

func (s *service) printIPToEndpoint(ip string) (string, bool) {
	return s.ipToEndpoint.String(ip)
}

type lbBackend struct {
	ip       net.IP
	disabled bool
}

type loadBalancer struct {
	vip    net.IP
	fwMark uint32

	// Map of backend IPs backing this loadbalancer on this
	// network. It is keyed with endpoint ID.
	backEnds map[string]*lbBackend

	// Back pointer to service to which the loadbalancer belongs.
	service *service
	sync.Mutex
}