open-consul/agent/metadata/server.go

package metadata

import (
	"fmt"
	"net"
	"regexp"
	"strconv"
	"strings"

	"github.com/hashicorp/go-version"
	"github.com/hashicorp/serf/serf"
)

// Key is used in maps and for equality tests.  A key is based on endpoints.
type Key struct {
	name string
}

// Equal compares two Key objects
func (k *Key) Equal(x *Key) bool {
	return k.name == x.name
}

// Server is used to return details of a consul server
type Server struct {
	Name         string // <node>.<dc>
	ShortName    string // <node>
	ID           string
	Datacenter   string
	Segment      string
	Port         int
	SegmentAddrs map[string]string
	SegmentPorts map[string]int
	WanJoinPort  int
	LanJoinPort  int

	// TODO why are these ports needed? It looks like nothing is referencing them.
	ExternalGRPCPort    int
	ExternalGRPCTLSPort int

	Bootstrap    bool
	Expect       int
	Build        version.Version
	Version      int
	RaftVersion  int
	Addr         net.Addr
	Status       serf.MemberStatus
	ReadReplica  bool
	FeatureFlags map[string]int

	// If true, use TLS when connecting to this server
	UseTLS bool
}

// Key returns the corresponding Key
func (s *Server) Key() *Key {
	return &Key{
		name: s.Name,
	}
}

// String returns a string representation of Server
func (s *Server) String() string {
	var addrStr, networkStr string
	if s.Addr != nil {
		addrStr = s.Addr.String()
		networkStr = s.Addr.Network()
	}

	return fmt.Sprintf("%s (Addr: %s/%s) (DC: %s)", s.Name, networkStr, addrStr, s.Datacenter)
}

var versionFormat = regexp.MustCompile(`\d+\.\d+\.\d+`)

// IsConsulServer returns true if a serf member is a consul server
// agent. Returns a bool and a pointer to the Server.
func IsConsulServer(m serf.Member) (bool, *Server) {
	if m.Tags["role"] != "consul" {
		return false, nil
	}

	datacenter := m.Tags["dc"]
	segment := m.Tags["segment"]
	_, bootstrap := m.Tags["bootstrap"]
	_, useTLS := m.Tags["use_tls"]

	expect := 0
	expectStr, ok := m.Tags["expect"]
	var err error
	if ok {
		expect, err = strconv.Atoi(expectStr)
		if err != nil {
			return false, nil
		}
	}

	portStr := m.Tags["port"]
	port, err := strconv.Atoi(portStr)
	if err != nil {
		return false, nil
	}

	segmentAddrs := make(map[string]string)
	segmentPorts := make(map[string]int)
	featureFlags := make(map[string]int)
	for name, value := range m.Tags {
		if strings.HasPrefix(name, "sl_") {
			addr, port, err := net.SplitHostPort(value)
			if err != nil {
				return false, nil
			}
			segmentPort, err := strconv.Atoi(port)
			if err != nil {
				return false, nil
			}

			segmentName := strings.TrimPrefix(name, "sl_")
			segmentAddrs[segmentName] = addr
			segmentPorts[segmentName] = segmentPort
		} else if strings.HasPrefix(name, featureFlagPrefix) {
			featureName := strings.TrimPrefix(name, featureFlagPrefix)
			featureState, err := strconv.Atoi(value)
			if err != nil {
				return false, nil
			}
			featureFlags[featureName] = featureState
		}
	}

	buildVersion, err := Build(&m)
	if err != nil {
		return false, nil
	}

	wanJoinPort := 0
	wanJoinPortStr, ok := m.Tags["wan_join_port"]
	if ok {
		wanJoinPort, err = strconv.Atoi(wanJoinPortStr)
		if err != nil {
			return false, nil
		}
	}

	var externalGRPCPort, externalGRPCTLSPort int
	externalGRPCPortStr, foundGRPC := m.Tags["grpc_port"]
	externalGRPCTLSPortStr, foundGRPCTLS := m.Tags["grpc_tls_port"]
	if foundGRPC {
		externalGRPCPort, _ = strconv.Atoi(externalGRPCPortStr)
	}
	if foundGRPCTLS {
		externalGRPCTLSPort, _ = strconv.Atoi(externalGRPCTLSPortStr)
	}
	// If either port tag was found, check to ensure that at least one port was valid.
	if foundGRPC || foundGRPCTLS {
		if externalGRPCPort < 1 && externalGRPCTLSPort < 1 {
			return false, nil
		}
	}

	vsnStr := m.Tags["vsn"]
	vsn, err := strconv.Atoi(vsnStr)
	if err != nil {
		return false, nil
	}

	raftVsn := 0
	raftVsnStr, ok := m.Tags["raft_vsn"]
	if ok {
		raftVsn, err = strconv.Atoi(raftVsnStr)
		if err != nil {
			return false, nil
		}
	}

	// Check if the server is a non voter
	// DEPRECATED - remove looking for the nonvoter tag eventually once we don't have to support
	// read replicas running v1.8.x and below.
	_, nonVoter := m.Tags["nonvoter"]
	_, readReplica := m.Tags["read_replica"]

	addr := &net.TCPAddr{IP: m.Addr, Port: port}

	parts := &Server{
		Name:                m.Name,
		ShortName:           strings.TrimSuffix(m.Name, "."+datacenter),
		ID:                  m.Tags["id"],
		Datacenter:          datacenter,
		Segment:             segment,
		Port:                port,
		SegmentAddrs:        segmentAddrs,
		SegmentPorts:        segmentPorts,
		WanJoinPort:         wanJoinPort,
		LanJoinPort:         int(m.Port),
		ExternalGRPCPort:    externalGRPCPort,
		ExternalGRPCTLSPort: externalGRPCTLSPort,
		Bootstrap:           bootstrap,
		Expect:              expect,
		Addr:                addr,
		Build:               *buildVersion,
		Version:             vsn,
		RaftVersion:         raftVsn,
		Status:              m.Status,
		UseTLS:              useTLS,
		// DEPRECATED - remove nonVoter check once support for that tag is removed
		ReadReplica:  nonVoter || readReplica,
		FeatureFlags: featureFlags,
	}
	return true, parts
}

// TODO(ACL-Legacy-Compat): remove in phase 2
const TagACLs = "acls"

const featureFlagPrefix = "ft_"

// AddFeatureFlags to the tags. The tags map is expected to be a serf.Config.Tags.
// The feature flags are encoded in the tags so that IsConsulServer can decode them
// and populate the Server.FeatureFlags map.
func AddFeatureFlags(tags map[string]string, flags ...string) {
	for _, flag := range flags {
		tags[featureFlagPrefix+flag] = "1"
	}
}