Function buildPortsRelatedCreateEndpointOptions

daemon/network.go:1036–1106

buildPortsRelatedCreateEndpointOptions returns the appropriate endpoint options to apply config related to port mapping and exposed ports.

(c *container.Container, n *libnetwork.Network, sb *libnetwork.Sandbox)

// buildPortsRelatedCreateEndpointOptions returns the appropriate endpoint options to apply config related to port
// mapping and exposed ports.
func buildPortsRelatedCreateEndpointOptions(c *container.Container, n *libnetwork.Network, sb *libnetwork.Sandbox) ([]libnetwork.EndpointOption, error) {
	// Port-mapping rules belong to the container & applicable only to non-internal networks.
	//
	// TODO(thaJeztah): Look if we can provide a more minimal function for getPortMapInfo, as it does a lot, and we only need the "length".
	if n.Internal() || len(getPortMapInfo(sb)) > 0 {
		return nil, nil
	}

	var (
		exposedPorts   []lntypes.TransportPort
		publishedPorts []lntypes.PortBinding
	)

	ports := c.HostConfig.PortBindings
	if c.HostConfig.PublishAllPorts && len(c.Config.ExposedPorts) > 0 {
		// Add exposed ports to a copy of the map to make sure a "publishedPorts" entry is created
		// for each exposed port, even if there's no specific binding.
		ports = maps.Clone(c.HostConfig.PortBindings)
		if ports == nil {
			ports = networktypes.PortMap{}
		}
		for p := range c.Config.ExposedPorts {
			if _, exists := ports[p]; !exists {
				ports[p] = nil
			}
		}
	}

	for p, bindings := range ports {
		protocol := lntypes.ParseProtocol(string(p.Proto()))
		exposedPorts = append(exposedPorts, lntypes.TransportPort{
			Proto: protocol,
			Port:  p.Num(),
		})

		for _, binding := range bindings {
			var (
				portRange networktypes.PortRange
				err       error
			)

			// Empty HostPort means to map to an ephemeral port.
			if binding.HostPort != "" {
				portRange, err = networktypes.ParsePortRange(binding.HostPort)
				if err != nil {
					return nil, fmt.Errorf("error parsing HostPort value(%s):%v", binding.HostPort, err)
				}
			}

			publishedPorts = append(publishedPorts, lntypes.PortBinding{
				Proto:       protocol,
				Port:        p.Num(),
				HostIP:      binding.HostIP.AsSlice(),
				HostPort:    portRange.Start(),
				HostPortEnd: portRange.End(),
			})
		}