open-consul/agent/agent.go
Frank Schroeder 226a5d3db4 agent: fix 'consul leave' shutdown race (#2880)
When the agent is triggered to shutdown via an external 'consul leave'
command delivered via the HTTP API then the client expects to receive a
response when the agent is down. This creates a race on when to shutdown
the agent itself like the RPC server, the checks and the state and the
external endpoints like DNS and HTTP. Ideally, the external endpoints
should be shutdown before the internal state but if the goal is to
respond reliably that the agent is down then this is not possible.

This patch splits the agent shutdown into two parts implemented in a
single method to keep it simple and unambiguos for the caller. The first
stage shuts down the internal state, checks, RPC server, ...
synchronously and then triggers the shutdown of the external endpoints
asychronously. This way the caller is guaranteed that the internal state
services are down when Shutdown returns and there remains enough time to
send a response.

Fixes #2880
2017-06-19 21:24:26 +02:00

2361 lines
67 KiB
Go

package agent
import (
"context"
"crypto/sha512"
"crypto/tls"
"encoding/json"
"errors"
"fmt"
"io"
"io/ioutil"
"log"
"net"
"net/http"
"os"
"path/filepath"
"reflect"
"regexp"
"strconv"
"strings"
"sync"
"time"
"github.com/hashicorp/consul/agent/consul"
"github.com/hashicorp/consul/agent/consul/state"
"github.com/hashicorp/consul/agent/consul/structs"
"github.com/hashicorp/consul/api"
"github.com/hashicorp/consul/ipaddr"
"github.com/hashicorp/consul/lib"
"github.com/hashicorp/consul/logger"
"github.com/hashicorp/consul/types"
"github.com/hashicorp/consul/watch"
multierror "github.com/hashicorp/go-multierror"
"github.com/hashicorp/go-sockaddr/template"
"github.com/hashicorp/go-uuid"
"github.com/hashicorp/raft"
"github.com/hashicorp/serf/coordinate"
"github.com/hashicorp/serf/serf"
"github.com/shirou/gopsutil/host"
)
const (
// Path to save agent service definitions
servicesDir = "services"
// Path to save local agent checks
checksDir = "checks"
checkStateDir = "checks/state"
// Default reasons for node/service maintenance mode
defaultNodeMaintReason = "Maintenance mode is enabled for this node, " +
"but no reason was provided. This is a default message."
defaultServiceMaintReason = "Maintenance mode is enabled for this " +
"service, but no reason was provided. This is a default message."
)
// dnsNameRe checks if a name or tag is dns-compatible.
var dnsNameRe = regexp.MustCompile(`^[a-zA-Z0-9\-]+$`)
// clientServer defines the interface shared by both
// consul.Client and consul.Server.
type clientServer interface {
Encrypted() bool
GetLANCoordinate() (*coordinate.Coordinate, error)
Leave() error
LANMembers() []serf.Member
LocalMember() serf.Member
JoinLAN(addrs []string) (n int, err error)
RemoveFailedNode(node string) error
RPC(method string, args interface{}, reply interface{}) error
SnapshotRPC(args *structs.SnapshotRequest, in io.Reader, out io.Writer, replyFn consul.SnapshotReplyFn) error
Shutdown() error
Stats() map[string]map[string]string
}
// The agent is the long running process that is run on every machine.
// It exposes an RPC interface that is used by the CLI to control the
// agent. The agent runs the query interfaces like HTTP, DNS, and RPC.
// However, it can run in either a client, or server mode. In server
// mode, it runs a full Consul server. In client-only mode, it only forwards
// requests to other Consul servers.
type Agent struct {
// config is the agent configuration.
config *Config
// Used for writing our logs
logger *log.Logger
// Output sink for logs
LogOutput io.Writer
// Used for streaming logs to
LogWriter *logger.LogWriter
// delegate is either a *consul.Server or *consul.Client
// depending on the configuration
delegate clientServer
// acls is an object that helps manage local ACL enforcement.
acls *aclManager
// state stores a local representation of the node,
// services and checks. Used for anti-entropy.
state localState
// checkReapAfter maps the check ID to a timeout after which we should
// reap its associated service
checkReapAfter map[types.CheckID]time.Duration
// checkMonitors maps the check ID to an associated monitor
checkMonitors map[types.CheckID]*CheckMonitor
// checkHTTPs maps the check ID to an associated HTTP check
checkHTTPs map[types.CheckID]*CheckHTTP
// checkTCPs maps the check ID to an associated TCP check
checkTCPs map[types.CheckID]*CheckTCP
// checkTTLs maps the check ID to an associated check TTL
checkTTLs map[types.CheckID]*CheckTTL
// checkDockers maps the check ID to an associated Docker Exec based check
checkDockers map[types.CheckID]*CheckDocker
// checkLock protects updates to the check* maps
checkLock sync.Mutex
// eventCh is used to receive user events
eventCh chan serf.UserEvent
// eventBuf stores the most recent events in a ring buffer
// using eventIndex as the next index to insert into. This
// is guarded by eventLock. When an insert happens, the
// eventNotify group is notified.
eventBuf []*UserEvent
eventIndex int
eventLock sync.RWMutex
eventNotify state.NotifyGroup
reloadCh chan chan error
shutdown bool
shutdownCh chan struct{}
shutdownLock sync.Mutex
// retryJoinCh transports errors from the retry join
// attempts.
retryJoinCh chan error
// endpoints lets you override RPC endpoints for testing. Not all
// agent methods use this, so use with care and never override
// outside of a unit test.
endpoints map[string]string
endpointsLock sync.RWMutex
// dnsAddr is the address the DNS server binds to
dnsAddrs []ProtoAddr
// dnsServer provides the DNS API
dnsServers []*DNSServer
// httpAddrs are the addresses per protocol the HTTP server binds to
httpAddrs []ProtoAddr
// httpServers provides the HTTP API on various endpoints
httpServers []*HTTPServer
// wgServers is the wait group for all HTTP and DNS servers
wgServers sync.WaitGroup
}
func New(c *Config) (*Agent, error) {
if c.Datacenter == "" {
return nil, fmt.Errorf("Must configure a Datacenter")
}
if c.DataDir == "" && !c.DevMode {
return nil, fmt.Errorf("Must configure a DataDir")
}
dnsAddrs, err := c.DNSAddrs()
if err != nil {
return nil, fmt.Errorf("Invalid DNS bind address: %s", err)
}
httpAddrs, err := c.HTTPAddrs()
if err != nil {
return nil, fmt.Errorf("Invalid HTTP bind address: %s", err)
}
acls, err := newACLManager(c)
if err != nil {
return nil, err
}
a := &Agent{
config: c,
acls: acls,
checkReapAfter: make(map[types.CheckID]time.Duration),
checkMonitors: make(map[types.CheckID]*CheckMonitor),
checkTTLs: make(map[types.CheckID]*CheckTTL),
checkHTTPs: make(map[types.CheckID]*CheckHTTP),
checkTCPs: make(map[types.CheckID]*CheckTCP),
checkDockers: make(map[types.CheckID]*CheckDocker),
eventCh: make(chan serf.UserEvent, 1024),
eventBuf: make([]*UserEvent, 256),
reloadCh: make(chan chan error),
retryJoinCh: make(chan error),
shutdownCh: make(chan struct{}),
endpoints: make(map[string]string),
dnsAddrs: dnsAddrs,
httpAddrs: httpAddrs,
}
if err := a.resolveTmplAddrs(); err != nil {
return nil, err
}
return a, nil
}
func (a *Agent) Start() error {
c := a.config
logOutput := a.LogOutput
if a.logger == nil {
if logOutput == nil {
logOutput = os.Stderr
}
a.logger = log.New(logOutput, "", log.LstdFlags)
}
// Retrieve or generate the node ID before setting up the rest of the
// agent, which depends on it.
if err := a.setupNodeID(c); err != nil {
return fmt.Errorf("Failed to setup node ID: %v", err)
}
// Initialize the local state.
a.state.Init(c, a.logger)
// Setup either the client or the server.
if c.Server {
server, err := a.makeServer()
if err != nil {
return err
}
a.delegate = server
a.state.SetIface(server)
// Automatically register the "consul" service on server nodes
consulService := structs.NodeService{
Service: consul.ConsulServiceName,
ID: consul.ConsulServiceID,
Port: c.Ports.Server,
Tags: []string{},
}
a.state.AddService(&consulService, c.GetTokenForAgent())
} else {
client, err := a.makeClient()
if err != nil {
return err
}
a.delegate = client
a.state.SetIface(client)
}
// Load checks/services/metadata.
if err := a.loadServices(c); err != nil {
return err
}
if err := a.loadChecks(c); err != nil {
return err
}
if err := a.loadMetadata(c); err != nil {
return err
}
// Start watching for critical services to deregister, based on their
// checks.
go a.reapServices()
// Start handling events.
go a.handleEvents()
// Start sending network coordinate to the server.
if !c.DisableCoordinates {
go a.sendCoordinate()
}
// Write out the PID file if necessary.
if err := a.storePid(); err != nil {
return err
}
// start DNS servers
if err := a.listenAndServeDNS(); err != nil {
return err
}
// create listeners and unstarted servers
// see comment on listenHTTP why we are doing this
httpln, err := a.listenHTTP(a.httpAddrs)
if err != nil {
return err
}
// start HTTP servers
for _, l := range httpln {
srv := NewHTTPServer(l.Addr().String(), a)
if err := a.serveHTTP(l, srv); err != nil {
return err
}
a.httpServers = append(a.httpServers, srv)
}
// register watches
if err := a.registerWatches(); err != nil {
return err
}
// start retry join
go a.retryJoin()
go a.retryJoinWan()
return nil
}
func (a *Agent) listenAndServeDNS() error {
notif := make(chan ProtoAddr, len(a.dnsAddrs))
for _, p := range a.dnsAddrs {
p := p // capture loop var
// create server
s, err := NewDNSServer(a)
if err != nil {
return err
}
a.dnsServers = append(a.dnsServers, s)
// start server
a.wgServers.Add(1)
go func() {
defer a.wgServers.Done()
err := s.ListenAndServe(p.Net, p.Addr, func() { notif <- p })
if err != nil && !strings.Contains(err.Error(), "accept") {
a.logger.Printf("[ERR] agent: Error starting DNS server %s (%s): %v", p.Addr, p.Net, err)
}
}()
}
// wait for servers to be up
timeout := time.After(time.Second)
for range a.dnsAddrs {
select {
case p := <-notif:
a.logger.Printf("[INFO] agent: Started DNS server %s (%s)", p.Addr, p.Net)
continue
case <-timeout:
return fmt.Errorf("agent: timeout starting DNS servers")
}
}
return nil
}
// listenHTTP binds listeners to the provided addresses and also returns
// pre-configured HTTP servers which are not yet started. The motivation is
// that in the current startup/shutdown setup we de-couple the listener
// creation from the server startup assuming that if any of the listeners
// cannot be bound we fail immediately and later failures do not occur.
// Therefore, starting a server with a running listener is assumed to not
// produce an error.
//
// The second motivation is that an HTTPS server needs to use the same TLSConfig
// on both the listener and the HTTP server. When listeners and servers are
// created at different times this becomes difficult to handle without keeping
// the TLS configuration somewhere or recreating it.
//
// This approach should ultimately be refactored to the point where we just
// start the server and any error should trigger a proper shutdown of the agent.
func (a *Agent) listenHTTP(addrs []ProtoAddr) ([]net.Listener, error) {
var ln []net.Listener
for _, p := range addrs {
var l net.Listener
var err error
switch {
case p.Net == "unix":
l, err = a.listenSocket(p.Addr, a.config.UnixSockets)
case p.Net == "tcp" && p.Proto == "http":
l, err = net.Listen("tcp", p.Addr)
case p.Net == "tcp" && p.Proto == "https":
var tlscfg *tls.Config
tlscfg, err = a.config.IncomingHTTPSConfig()
if err != nil {
break
}
l, err = tls.Listen("tcp", p.Addr, tlscfg)
default:
return nil, fmt.Errorf("%s:%s listener not supported", p.Net, p.Proto)
}
if err != nil {
for _, l := range ln {
l.Close()
}
return nil, err
}
if tcpl, ok := l.(*net.TCPListener); ok {
l = &tcpKeepAliveListener{tcpl}
}
ln = append(ln, l)
}
return ln, nil
}
// tcpKeepAliveListener sets TCP keep-alive timeouts on accepted
// connections. It's used by NewHttpServer so dead TCP connections
// eventually go away.
type tcpKeepAliveListener struct {
*net.TCPListener
}
func (ln tcpKeepAliveListener) Accept() (c net.Conn, err error) {
tc, err := ln.AcceptTCP()
if err != nil {
return
}
tc.SetKeepAlive(true)
tc.SetKeepAlivePeriod(30 * time.Second)
return tc, nil
}
func (a *Agent) listenSocket(path string, perm FilePermissions) (net.Listener, error) {
if _, err := os.Stat(path); !os.IsNotExist(err) {
a.logger.Printf("[WARN] agent: Replacing socket %q", path)
}
if err := os.Remove(path); err != nil && !os.IsNotExist(err) {
return nil, fmt.Errorf("error removing socket file: %s", err)
}
l, err := net.Listen("unix", path)
if err != nil {
return nil, err
}
if err := setFilePermissions(path, perm); err != nil {
return nil, fmt.Errorf("Failed setting up HTTP socket: %s", err)
}
return l, nil
}
func (a *Agent) serveHTTP(l net.Listener, srv *HTTPServer) error {
// https://github.com/golang/go/issues/20239
//
// In go.8.1 there is a race between Serve and Shutdown. If
// Shutdown is called before the Serve go routine was scheduled then
// the Serve go routine never returns. This deadlocks the agent
// shutdown for some tests since it will wait forever.
//
// Since we need to check for an unexported type (*tls.listener)
// we cannot just perform a type check since the compiler won't let
// us. We might be able to use reflection but the fmt.Sprintf() hack
// works just as well.
srv.proto = "http"
if strings.Contains("*tls.listener", fmt.Sprintf("%T", l)) {
srv.proto = "https"
}
notif := make(chan string)
a.wgServers.Add(1)
go func() {
defer a.wgServers.Done()
notif <- srv.Addr
err := srv.Serve(l)
if err != nil && err != http.ErrServerClosed {
a.logger.Print(err)
}
}()
select {
case addr := <-notif:
if srv.proto == "https" {
a.logger.Printf("[INFO] agent: Started HTTPS server on %s", addr)
} else {
a.logger.Printf("[INFO] agent: Started HTTP server on %s", addr)
}
return nil
case <-time.After(time.Second):
return fmt.Errorf("agent: timeout starting HTTP servers")
}
}
func (a *Agent) registerWatches() error {
if len(a.config.WatchPlans) == 0 {
return nil
}
addrs, err := a.config.HTTPAddrs()
if err != nil {
return err
}
if len(addrs) == 0 {
return fmt.Errorf("watch plans require an HTTP or HTTPS endpoint")
}
for _, wp := range a.config.WatchPlans {
go func(wp *watch.Plan) {
wp.Handler = makeWatchHandler(a.LogOutput, wp.Exempt["handler"])
wp.LogOutput = a.LogOutput
addr := addrs[0].String()
if addrs[0].Net == "unix" {
addr = "unix://" + addr
}
if err := wp.Run(addr); err != nil {
a.logger.Println("[ERR] Failed to run watch: %v", err)
}
}(wp)
}
return nil
}
// consulConfig is used to return a consul configuration
func (a *Agent) consulConfig() (*consul.Config, error) {
// Start with the provided config or default config
base := consul.DefaultConfig()
if a.config.ConsulConfig != nil {
base = a.config.ConsulConfig
}
// This is set when the agent starts up
base.NodeID = a.config.NodeID
// Apply dev mode
base.DevMode = a.config.DevMode
// Apply performance factors
if a.config.Performance.RaftMultiplier > 0 {
base.ScaleRaft(a.config.Performance.RaftMultiplier)
}
// Override with our config
if a.config.Datacenter != "" {
base.Datacenter = a.config.Datacenter
}
if a.config.DataDir != "" {
base.DataDir = a.config.DataDir
}
if a.config.NodeName != "" {
base.NodeName = a.config.NodeName
}
if a.config.Ports.SerfLan != 0 {
base.SerfLANConfig.MemberlistConfig.BindPort = a.config.Ports.SerfLan
base.SerfLANConfig.MemberlistConfig.AdvertisePort = a.config.Ports.SerfLan
}
if a.config.Ports.SerfWan != 0 {
base.SerfWANConfig.MemberlistConfig.BindPort = a.config.Ports.SerfWan
base.SerfWANConfig.MemberlistConfig.AdvertisePort = a.config.Ports.SerfWan
}
if a.config.BindAddr != "" {
bindAddr := &net.TCPAddr{
IP: net.ParseIP(a.config.BindAddr),
Port: a.config.Ports.Server,
}
base.RPCAddr = bindAddr
// Set the Serf configs using the old default behavior, we may
// override these in the code right below.
base.SerfLANConfig.MemberlistConfig.BindAddr = a.config.BindAddr
base.SerfWANConfig.MemberlistConfig.BindAddr = a.config.BindAddr
}
if a.config.SerfLanBindAddr != "" {
base.SerfLANConfig.MemberlistConfig.BindAddr = a.config.SerfLanBindAddr
}
if a.config.SerfWanBindAddr != "" {
base.SerfWANConfig.MemberlistConfig.BindAddr = a.config.SerfWanBindAddr
}
// Try to get an advertise address
switch {
case a.config.AdvertiseAddr != "":
ipStr, err := parseSingleIPTemplate(a.config.AdvertiseAddr)
if err != nil {
return nil, fmt.Errorf("Advertise address resolution failed: %v", err)
}
if net.ParseIP(ipStr) == nil {
return nil, fmt.Errorf("Failed to parse advertise address: %v", ipStr)
}
a.config.AdvertiseAddr = ipStr
case a.config.BindAddr != "" && !ipaddr.IsAny(a.config.BindAddr):
a.config.AdvertiseAddr = a.config.BindAddr
default:
ip, err := consul.GetPrivateIP()
if ipaddr.IsAnyV6(a.config.BindAddr) {
ip, err = consul.GetPublicIPv6()
}
if err != nil {
return nil, fmt.Errorf("Failed to get advertise address: %v", err)
}
a.config.AdvertiseAddr = ip.String()
}
// Try to get an advertise address for the wan
if a.config.AdvertiseAddrWan != "" {
ipStr, err := parseSingleIPTemplate(a.config.AdvertiseAddrWan)
if err != nil {
return nil, fmt.Errorf("Advertise WAN address resolution failed: %v", err)
}
if net.ParseIP(ipStr) == nil {
return nil, fmt.Errorf("Failed to parse advertise address for WAN: %v", ipStr)
}
a.config.AdvertiseAddrWan = ipStr
} else {
a.config.AdvertiseAddrWan = a.config.AdvertiseAddr
}
// Create the default set of tagged addresses.
a.config.TaggedAddresses = map[string]string{
"lan": a.config.AdvertiseAddr,
"wan": a.config.AdvertiseAddrWan,
}
if a.config.AdvertiseAddr != "" {
base.SerfLANConfig.MemberlistConfig.AdvertiseAddr = a.config.AdvertiseAddr
base.SerfWANConfig.MemberlistConfig.AdvertiseAddr = a.config.AdvertiseAddr
if a.config.AdvertiseAddrWan != "" {
base.SerfWANConfig.MemberlistConfig.AdvertiseAddr = a.config.AdvertiseAddrWan
}
base.RPCAdvertise = &net.TCPAddr{
IP: net.ParseIP(a.config.AdvertiseAddr),
Port: a.config.Ports.Server,
}
}
if a.config.AdvertiseAddrs.SerfLan != nil {
base.SerfLANConfig.MemberlistConfig.AdvertiseAddr = a.config.AdvertiseAddrs.SerfLan.IP.String()
base.SerfLANConfig.MemberlistConfig.AdvertisePort = a.config.AdvertiseAddrs.SerfLan.Port
}
if a.config.AdvertiseAddrs.SerfWan != nil {
base.SerfWANConfig.MemberlistConfig.AdvertiseAddr = a.config.AdvertiseAddrs.SerfWan.IP.String()
base.SerfWANConfig.MemberlistConfig.AdvertisePort = a.config.AdvertiseAddrs.SerfWan.Port
}
if a.config.ReconnectTimeoutLan != 0 {
base.SerfLANConfig.ReconnectTimeout = a.config.ReconnectTimeoutLan
}
if a.config.ReconnectTimeoutWan != 0 {
base.SerfWANConfig.ReconnectTimeout = a.config.ReconnectTimeoutWan
}
if a.config.EncryptVerifyIncoming != nil {
base.SerfWANConfig.MemberlistConfig.GossipVerifyIncoming = *a.config.EncryptVerifyIncoming
base.SerfLANConfig.MemberlistConfig.GossipVerifyIncoming = *a.config.EncryptVerifyIncoming
}
if a.config.EncryptVerifyOutgoing != nil {
base.SerfWANConfig.MemberlistConfig.GossipVerifyOutgoing = *a.config.EncryptVerifyOutgoing
base.SerfLANConfig.MemberlistConfig.GossipVerifyOutgoing = *a.config.EncryptVerifyOutgoing
}
if a.config.AdvertiseAddrs.RPC != nil {
base.RPCAdvertise = a.config.AdvertiseAddrs.RPC
}
if a.config.Bootstrap {
base.Bootstrap = true
}
if a.config.RejoinAfterLeave {
base.RejoinAfterLeave = true
}
if a.config.BootstrapExpect != 0 {
base.BootstrapExpect = a.config.BootstrapExpect
}
if a.config.Protocol > 0 {
base.ProtocolVersion = uint8(a.config.Protocol)
}
if a.config.RaftProtocol != 0 {
base.RaftConfig.ProtocolVersion = raft.ProtocolVersion(a.config.RaftProtocol)
}
if a.config.ACLToken != "" {
base.ACLToken = a.config.ACLToken
}
if a.config.ACLAgentToken != "" {
base.ACLAgentToken = a.config.ACLAgentToken
}
if a.config.ACLMasterToken != "" {
base.ACLMasterToken = a.config.ACLMasterToken
}
if a.config.ACLDatacenter != "" {
base.ACLDatacenter = a.config.ACLDatacenter
}
if a.config.ACLTTLRaw != "" {
base.ACLTTL = a.config.ACLTTL
}
if a.config.ACLDefaultPolicy != "" {
base.ACLDefaultPolicy = a.config.ACLDefaultPolicy
}
if a.config.ACLDownPolicy != "" {
base.ACLDownPolicy = a.config.ACLDownPolicy
}
if a.config.ACLReplicationToken != "" {
base.ACLReplicationToken = a.config.ACLReplicationToken
}
if a.config.ACLEnforceVersion8 != nil {
base.ACLEnforceVersion8 = *a.config.ACLEnforceVersion8
}
if a.config.SessionTTLMinRaw != "" {
base.SessionTTLMin = a.config.SessionTTLMin
}
if a.config.Autopilot.CleanupDeadServers != nil {
base.AutopilotConfig.CleanupDeadServers = *a.config.Autopilot.CleanupDeadServers
}
if a.config.Autopilot.LastContactThreshold != nil {
base.AutopilotConfig.LastContactThreshold = *a.config.Autopilot.LastContactThreshold
}
if a.config.Autopilot.MaxTrailingLogs != nil {
base.AutopilotConfig.MaxTrailingLogs = *a.config.Autopilot.MaxTrailingLogs
}
if a.config.Autopilot.ServerStabilizationTime != nil {
base.AutopilotConfig.ServerStabilizationTime = *a.config.Autopilot.ServerStabilizationTime
}
if a.config.NonVotingServer {
base.NonVoter = a.config.NonVotingServer
}
if a.config.Autopilot.RedundancyZoneTag != "" {
base.AutopilotConfig.RedundancyZoneTag = a.config.Autopilot.RedundancyZoneTag
}
if a.config.Autopilot.DisableUpgradeMigration != nil {
base.AutopilotConfig.DisableUpgradeMigration = *a.config.Autopilot.DisableUpgradeMigration
}
// make sure the advertise address is always set
if base.RPCAdvertise == nil {
base.RPCAdvertise = base.RPCAddr
}
// set the src address for outgoing rpc connections
// Use port 0 so that outgoing connections use a random port.
if !ipaddr.IsAny(base.RPCAddr.IP) {
base.RPCSrcAddr = &net.TCPAddr{IP: base.RPCAddr.IP}
}
// Format the build string
revision := a.config.Revision
if len(revision) > 8 {
revision = revision[:8]
}
base.Build = fmt.Sprintf("%s%s:%s", a.config.Version, a.config.VersionPrerelease, revision)
// Copy the TLS configuration
base.VerifyIncoming = a.config.VerifyIncoming || a.config.VerifyIncomingRPC
if a.config.CAPath != "" || a.config.CAFile != "" {
base.UseTLS = true
}
base.VerifyOutgoing = a.config.VerifyOutgoing
base.VerifyServerHostname = a.config.VerifyServerHostname
base.CAFile = a.config.CAFile
base.CAPath = a.config.CAPath
base.CertFile = a.config.CertFile
base.KeyFile = a.config.KeyFile
base.ServerName = a.config.ServerName
base.Domain = a.config.Domain
base.TLSMinVersion = a.config.TLSMinVersion
base.TLSCipherSuites = a.config.TLSCipherSuites
base.TLSPreferServerCipherSuites = a.config.TLSPreferServerCipherSuites
// Setup the ServerUp callback
base.ServerUp = a.state.ConsulServerUp
// Setup the user event callback
base.UserEventHandler = func(e serf.UserEvent) {
select {
case a.eventCh <- e:
case <-a.shutdownCh:
}
}
// Setup the loggers
base.LogOutput = a.LogOutput
return base, nil
}
// parseSingleIPTemplate is used as a helper function to parse out a single IP
// address from a config parameter.
func parseSingleIPTemplate(ipTmpl string) (string, error) {
out, err := template.Parse(ipTmpl)
if err != nil {
return "", fmt.Errorf("Unable to parse address template %q: %v", ipTmpl, err)
}
ips := strings.Split(out, " ")
switch len(ips) {
case 0:
return "", errors.New("No addresses found, please configure one.")
case 1:
return ips[0], nil
default:
return "", fmt.Errorf("Multiple addresses found (%q), please configure one.", out)
}
}
// resolveTmplAddrs iterates over the myriad of addresses in the agent's config
// and performs go-sockaddr/template Parse on each known address in case the
// user specified a template config for any of their values.
func (a *Agent) resolveTmplAddrs() error {
if a.config.AdvertiseAddr != "" {
ipStr, err := parseSingleIPTemplate(a.config.AdvertiseAddr)
if err != nil {
return fmt.Errorf("Advertise address resolution failed: %v", err)
}
a.config.AdvertiseAddr = ipStr
}
if a.config.Addresses.DNS != "" {
ipStr, err := parseSingleIPTemplate(a.config.Addresses.DNS)
if err != nil {
return fmt.Errorf("DNS address resolution failed: %v", err)
}
a.config.Addresses.DNS = ipStr
}
if a.config.Addresses.HTTP != "" {
ipStr, err := parseSingleIPTemplate(a.config.Addresses.HTTP)
if err != nil {
return fmt.Errorf("HTTP address resolution failed: %v", err)
}
a.config.Addresses.HTTP = ipStr
}
if a.config.Addresses.HTTPS != "" {
ipStr, err := parseSingleIPTemplate(a.config.Addresses.HTTPS)
if err != nil {
return fmt.Errorf("HTTPS address resolution failed: %v", err)
}
a.config.Addresses.HTTPS = ipStr
}
if a.config.AdvertiseAddrWan != "" {
ipStr, err := parseSingleIPTemplate(a.config.AdvertiseAddrWan)
if err != nil {
return fmt.Errorf("Advertise WAN address resolution failed: %v", err)
}
a.config.AdvertiseAddrWan = ipStr
}
if a.config.BindAddr != "" {
ipStr, err := parseSingleIPTemplate(a.config.BindAddr)
if err != nil {
return fmt.Errorf("Bind address resolution failed: %v", err)
}
a.config.BindAddr = ipStr
}
if a.config.ClientAddr != "" {
ipStr, err := parseSingleIPTemplate(a.config.ClientAddr)
if err != nil {
return fmt.Errorf("Client address resolution failed: %v", err)
}
a.config.ClientAddr = ipStr
}
if a.config.SerfLanBindAddr != "" {
ipStr, err := parseSingleIPTemplate(a.config.SerfLanBindAddr)
if err != nil {
return fmt.Errorf("Serf LAN Address resolution failed: %v", err)
}
a.config.SerfLanBindAddr = ipStr
}
if a.config.SerfWanBindAddr != "" {
ipStr, err := parseSingleIPTemplate(a.config.SerfWanBindAddr)
if err != nil {
return fmt.Errorf("Serf WAN Address resolution failed: %v", err)
}
a.config.SerfWanBindAddr = ipStr
}
// Parse all tagged addresses
for k, v := range a.config.TaggedAddresses {
ipStr, err := parseSingleIPTemplate(v)
if err != nil {
return fmt.Errorf("%s address resolution failed: %v", k, err)
}
a.config.TaggedAddresses[k] = ipStr
}
return nil
}
// makeServer creates a new consul server.
func (a *Agent) makeServer() (*consul.Server, error) {
config, err := a.consulConfig()
if err != nil {
return nil, err
}
if !a.config.DisableKeyringFile {
if err := a.setupKeyrings(config); err != nil {
return nil, fmt.Errorf("Failed to configure keyring: %v", err)
}
}
server, err := consul.NewServerLogger(config, a.logger)
if err != nil {
return nil, fmt.Errorf("Failed to start Consul server: %v", err)
}
return server, nil
}
// makeClient creates a new consul client.
func (a *Agent) makeClient() (*consul.Client, error) {
config, err := a.consulConfig()
if err != nil {
return nil, err
}
if !a.config.DisableKeyringFile {
if err := a.setupKeyrings(config); err != nil {
return nil, fmt.Errorf("Failed to configure keyring: %v", err)
}
}
client, err := consul.NewClientLogger(config, a.logger)
if err != nil {
return nil, fmt.Errorf("Failed to start Consul client: %v", err)
}
return client, nil
}
// makeRandomID will generate a random UUID for a node.
func (a *Agent) makeRandomID() (string, error) {
id, err := uuid.GenerateUUID()
if err != nil {
return "", err
}
a.logger.Printf("[DEBUG] Using random ID %q as node ID", id)
return id, nil
}
// makeNodeID will try to find a host-specific ID, or else will generate a
// random ID. The returned ID will always be formatted as a GUID. We don't tell
// the caller whether this ID is random or stable since the consequences are
// high for us if this changes, so we will persist it either way. This will let
// gopsutil change implementations without affecting in-place upgrades of nodes.
func (a *Agent) makeNodeID() (string, error) {
// If they've disabled host-based IDs then just make a random one.
if a.config.DisableHostNodeID {
return a.makeRandomID()
}
// Try to get a stable ID associated with the host itself.
info, err := host.Info()
if err != nil {
a.logger.Printf("[DEBUG] Couldn't get a unique ID from the host: %v", err)
return a.makeRandomID()
}
// Make sure the host ID parses as a UUID, since we don't have complete
// control over this process.
id := strings.ToLower(info.HostID)
if _, err := uuid.ParseUUID(id); err != nil {
a.logger.Printf("[DEBUG] Unique ID %q from host isn't formatted as a UUID: %v",
id, err)
return a.makeRandomID()
}
// Hash the input to make it well distributed. The reported Host UUID may be
// similar across nodes if they are on a cloud provider or on motherboards
// created from the same batch.
buf := sha512.Sum512([]byte(id))
id = fmt.Sprintf("%08x-%04x-%04x-%04x-%12x",
buf[0:4],
buf[4:6],
buf[6:8],
buf[8:10],
buf[10:16])
a.logger.Printf("[DEBUG] Using unique ID %q from host as node ID", id)
return id, nil
}
// setupNodeID will pull the persisted node ID, if any, or create a random one
// and persist it.
func (a *Agent) setupNodeID(config *Config) error {
// If they've configured a node ID manually then just use that, as
// long as it's valid.
if config.NodeID != "" {
config.NodeID = types.NodeID(strings.ToLower(string(config.NodeID)))
if _, err := uuid.ParseUUID(string(config.NodeID)); err != nil {
return err
}
return nil
}
// For dev mode we have no filesystem access so just make one.
if a.config.DevMode {
id, err := a.makeNodeID()
if err != nil {
return err
}
config.NodeID = types.NodeID(id)
return nil
}
// Load saved state, if any. Since a user could edit this, we also
// validate it.
fileID := filepath.Join(config.DataDir, "node-id")
if _, err := os.Stat(fileID); err == nil {
rawID, err := ioutil.ReadFile(fileID)
if err != nil {
return err
}
nodeID := strings.TrimSpace(string(rawID))
nodeID = strings.ToLower(nodeID)
if _, err := uuid.ParseUUID(nodeID); err != nil {
return err
}
config.NodeID = types.NodeID(nodeID)
}
// If we still don't have a valid node ID, make one.
if config.NodeID == "" {
id, err := a.makeNodeID()
if err != nil {
return err
}
if err := lib.EnsurePath(fileID, false); err != nil {
return err
}
if err := ioutil.WriteFile(fileID, []byte(id), 0600); err != nil {
return err
}
config.NodeID = types.NodeID(id)
}
return nil
}
// setupKeyrings is used to initialize and load keyrings during agent startup
func (a *Agent) setupKeyrings(config *consul.Config) error {
fileLAN := filepath.Join(a.config.DataDir, SerfLANKeyring)
fileWAN := filepath.Join(a.config.DataDir, SerfWANKeyring)
if a.config.EncryptKey == "" {
goto LOAD
}
if _, err := os.Stat(fileLAN); err != nil {
if err := initKeyring(fileLAN, a.config.EncryptKey); err != nil {
return err
}
}
if a.config.Server {
if _, err := os.Stat(fileWAN); err != nil {
if err := initKeyring(fileWAN, a.config.EncryptKey); err != nil {
return err
}
}
}
LOAD:
if _, err := os.Stat(fileLAN); err == nil {
config.SerfLANConfig.KeyringFile = fileLAN
}
if err := loadKeyringFile(config.SerfLANConfig); err != nil {
return err
}
if a.config.Server {
if _, err := os.Stat(fileWAN); err == nil {
config.SerfWANConfig.KeyringFile = fileWAN
}
if err := loadKeyringFile(config.SerfWANConfig); err != nil {
return err
}
}
// Success!
return nil
}
// RPC is used to make an RPC call to the Consul servers
// This allows the agent to implement the Consul.Interface
func (a *Agent) RPC(method string, args interface{}, reply interface{}) error {
return a.delegate.RPC(method, args, reply)
}
// SnapshotRPC performs the requested snapshot RPC against the Consul server in
// a streaming manner. The contents of in will be read and passed along as the
// payload, and the response message will determine the error status, and any
// return payload will be written to out.
func (a *Agent) SnapshotRPC(args *structs.SnapshotRequest, in io.Reader, out io.Writer,
replyFn consul.SnapshotReplyFn) error {
return a.delegate.SnapshotRPC(args, in, out, replyFn)
}
// Leave is used to prepare the agent for a graceful shutdown
func (a *Agent) Leave() error {
return a.delegate.Leave()
}
// Shutdown is used to hard stop the agent. Should be
// preceded by a call to Leave to do it gracefully.
func (a *Agent) Shutdown() error {
// Execute the shutdown in two stages since it may have been
// triggered through the HTTP server via 'consul leave'. In this
// case the HTTP server needs to be up after the agent is down in
// order to deliver the response. The 'consul leave' handler waits
// for the Shutdown() method to complete before delivering the
// response.
//
// This could also be implemented through multiple methods to
// decouple this in a different way but then this logic would have
// to be implemented everywhere. This way the logic remains in a
// single place.
a.shutdownLock.Lock()
defer a.shutdownLock.Unlock()
if a.shutdown {
return nil
}
a.logger.Println("[INFO] agent: Requesting shutdown")
// stage 1: shutdown agent w/o HTTP and DNS endpoints
// Stop all the checks
a.checkLock.Lock()
defer a.checkLock.Unlock()
for _, chk := range a.checkMonitors {
chk.Stop()
}
for _, chk := range a.checkTTLs {
chk.Stop()
}
for _, chk := range a.checkHTTPs {
chk.Stop()
}
for _, chk := range a.checkTCPs {
chk.Stop()
}
var err error
if a.delegate != nil {
err = a.delegate.Shutdown()
if _, ok := a.delegate.(*consul.Server); ok {
a.logger.Print("[INFO] agent: consul server down")
} else {
a.logger.Print("[INFO] agent: consul client down")
}
}
pidErr := a.deletePid()
if pidErr != nil {
a.logger.Println("[WARN] agent: could not delete pid file ", pidErr)
}
// stage 2: shutdown HTTP and DNS endpoints and trigger final shutdown notification
go func() {
// Stop all API endpoints
for _, srv := range a.dnsServers {
a.logger.Printf("[INFO] agent: Stopping DNS server %s (%s)", srv.Server.Addr, srv.Server.Net)
srv.Shutdown()
}
for _, srv := range a.httpServers {
a.logger.Printf("[INFO] agent: Stopping %s server %s", strings.ToUpper(srv.proto), srv.Addr)
ctx, cancel := context.WithTimeout(context.Background(), time.Second)
defer cancel()
srv.Shutdown(ctx)
if ctx.Err() == context.DeadlineExceeded {
a.logger.Printf("[WARN] agent: Timeout stopping %s server %s", strings.ToUpper(srv.proto), srv.Addr)
}
}
a.logger.Println("[INFO] agent: Waiting for endpoints to shut down")
a.wgServers.Wait()
a.logger.Print("[INFO] agent: Endpoints down")
a.logger.Println("[INFO] agent: shutdown complete")
close(a.shutdownCh)
}()
a.shutdown = true
return err
}
// ReloadCh is used to return a channel that can be
// used for triggering reloads and returning a response.
func (a *Agent) ReloadCh() chan chan error {
return a.reloadCh
}
// RetryJoinCh is a channel that transports errors
// from the retry join process.
func (a *Agent) RetryJoinCh() <-chan error {
return a.retryJoinCh
}
// ShutdownCh is used to return a channel that can be
// selected to wait for the agent to perform a shutdown.
func (a *Agent) ShutdownCh() <-chan struct{} {
return a.shutdownCh
}
// JoinLAN is used to have the agent join a LAN cluster
func (a *Agent) JoinLAN(addrs []string) (n int, err error) {
a.logger.Printf("[INFO] agent: (LAN) joining: %v", addrs)
n, err = a.delegate.JoinLAN(addrs)
a.logger.Printf("[INFO] agent: (LAN) joined: %d Err: %v", n, err)
return
}
// JoinWAN is used to have the agent join a WAN cluster
func (a *Agent) JoinWAN(addrs []string) (n int, err error) {
a.logger.Printf("[INFO] agent: (WAN) joining: %v", addrs)
if srv, ok := a.delegate.(*consul.Server); ok {
n, err = srv.JoinWAN(addrs)
} else {
err = fmt.Errorf("Must be a server to join WAN cluster")
}
a.logger.Printf("[INFO] agent: (WAN) joined: %d Err: %v", n, err)
return
}
// ForceLeave is used to remove a failed node from the cluster
func (a *Agent) ForceLeave(node string) (err error) {
a.logger.Printf("[INFO] Force leaving node: %v", node)
err = a.delegate.RemoveFailedNode(node)
if err != nil {
a.logger.Printf("[WARN] Failed to remove node: %v", err)
}
return err
}
// LocalMember is used to return the local node
func (a *Agent) LocalMember() serf.Member {
return a.delegate.LocalMember()
}
// LANMembers is used to retrieve the LAN members
func (a *Agent) LANMembers() []serf.Member {
return a.delegate.LANMembers()
}
// WANMembers is used to retrieve the WAN members
func (a *Agent) WANMembers() []serf.Member {
if srv, ok := a.delegate.(*consul.Server); ok {
return srv.WANMembers()
}
return nil
}
// StartSync is called once Services and Checks are registered.
// This is called to prevent a race between clients and the anti-entropy routines
func (a *Agent) StartSync() {
// Start the anti entropy routine
go a.state.antiEntropy(a.shutdownCh)
}
// PauseSync is used to pause anti-entropy while bulk changes are make
func (a *Agent) PauseSync() {
a.state.Pause()
}
// ResumeSync is used to unpause anti-entropy after bulk changes are make
func (a *Agent) ResumeSync() {
a.state.Resume()
}
// GetLANCoordinate returns the coordinate of this node in the local pool (assumes coordinates
// are enabled, so check that before calling).
func (a *Agent) GetLANCoordinate() (*coordinate.Coordinate, error) {
return a.delegate.GetLANCoordinate()
}
// sendCoordinate is a long-running loop that periodically sends our coordinate
// to the server. Closing the agent's shutdownChannel will cause this to exit.
func (a *Agent) sendCoordinate() {
for {
rate := a.config.SyncCoordinateRateTarget
min := a.config.SyncCoordinateIntervalMin
intv := lib.RateScaledInterval(rate, min, len(a.LANMembers()))
intv = intv + lib.RandomStagger(intv)
select {
case <-time.After(intv):
members := a.LANMembers()
grok, err := consul.CanServersUnderstandProtocol(members, 3)
if err != nil {
a.logger.Printf("[ERR] agent: failed to check servers: %s", err)
continue
}
if !grok {
a.logger.Printf("[DEBUG] agent: skipping coordinate updates until servers are upgraded")
continue
}
c, err := a.GetLANCoordinate()
if err != nil {
a.logger.Printf("[ERR] agent: failed to get coordinate: %s", err)
continue
}
req := structs.CoordinateUpdateRequest{
Datacenter: a.config.Datacenter,
Node: a.config.NodeName,
Coord: c,
WriteRequest: structs.WriteRequest{Token: a.config.GetTokenForAgent()},
}
var reply struct{}
if err := a.RPC("Coordinate.Update", &req, &reply); err != nil {
a.logger.Printf("[ERR] agent: coordinate update error: %s", err)
continue
}
case <-a.shutdownCh:
return
}
}
}
// reapServicesInternal does a single pass, looking for services to reap.
func (a *Agent) reapServicesInternal() {
reaped := make(map[string]struct{})
for checkID, check := range a.state.CriticalChecks() {
// There's nothing to do if there's no service.
if check.Check.ServiceID == "" {
continue
}
// There might be multiple checks for one service, so
// we don't need to reap multiple times.
serviceID := check.Check.ServiceID
if _, ok := reaped[serviceID]; ok {
continue
}
// See if there's a timeout.
a.checkLock.Lock()
timeout, ok := a.checkReapAfter[checkID]
a.checkLock.Unlock()
// Reap, if necessary. We keep track of which service
// this is so that we won't try to remove it again.
if ok && check.CriticalFor > timeout {
reaped[serviceID] = struct{}{}
a.RemoveService(serviceID, true)
a.logger.Printf("[INFO] agent: Check %q for service %q has been critical for too long; deregistered service",
checkID, serviceID)
}
}
}
// reapServices is a long running goroutine that looks for checks that have been
// critical too long and dregisters their associated services.
func (a *Agent) reapServices() {
for {
select {
case <-time.After(a.config.CheckReapInterval):
a.reapServicesInternal()
case <-a.shutdownCh:
return
}
}
}
// persistService saves a service definition to a JSON file in the data dir
func (a *Agent) persistService(service *structs.NodeService) error {
svcPath := filepath.Join(a.config.DataDir, servicesDir, stringHash(service.ID))
wrapped := persistedService{
Token: a.state.ServiceToken(service.ID),
Service: service,
}
encoded, err := json.Marshal(wrapped)
if err != nil {
return err
}
return writeFileAtomic(svcPath, encoded)
}
// purgeService removes a persisted service definition file from the data dir
func (a *Agent) purgeService(serviceID string) error {
svcPath := filepath.Join(a.config.DataDir, servicesDir, stringHash(serviceID))
if _, err := os.Stat(svcPath); err == nil {
return os.Remove(svcPath)
}
return nil
}
// persistCheck saves a check definition to the local agent's state directory
func (a *Agent) persistCheck(check *structs.HealthCheck, chkType *CheckType) error {
checkPath := filepath.Join(a.config.DataDir, checksDir, checkIDHash(check.CheckID))
// Create the persisted check
wrapped := persistedCheck{
Check: check,
ChkType: chkType,
Token: a.state.CheckToken(check.CheckID),
}
encoded, err := json.Marshal(wrapped)
if err != nil {
return err
}
return writeFileAtomic(checkPath, encoded)
}
// purgeCheck removes a persisted check definition file from the data dir
func (a *Agent) purgeCheck(checkID types.CheckID) error {
checkPath := filepath.Join(a.config.DataDir, checksDir, checkIDHash(checkID))
if _, err := os.Stat(checkPath); err == nil {
return os.Remove(checkPath)
}
return nil
}
// writeFileAtomic writes the given contents to a temporary file in the same
// directory, does an fsync and then renames the file to its real path
func writeFileAtomic(path string, contents []byte) error {
uuid, err := uuid.GenerateUUID()
if err != nil {
return err
}
tempPath := fmt.Sprintf("%s-%s.tmp", path, uuid)
if err := os.MkdirAll(filepath.Dir(path), 0700); err != nil {
return err
}
fh, err := os.OpenFile(tempPath, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0600)
if err != nil {
return err
}
if _, err := fh.Write(contents); err != nil {
return err
}
if err := fh.Sync(); err != nil {
return err
}
if err := fh.Close(); err != nil {
return err
}
return os.Rename(tempPath, path)
}
// AddService is used to add a service entry.
// This entry is persistent and the agent will make a best effort to
// ensure it is registered
func (a *Agent) AddService(service *structs.NodeService, chkTypes CheckTypes, persist bool, token string) error {
if service.Service == "" {
return fmt.Errorf("Service name missing")
}
if service.ID == "" && service.Service != "" {
service.ID = service.Service
}
for _, check := range chkTypes {
if !check.Valid() {
return fmt.Errorf("Check type is not valid")
}
}
// Warn if the service name is incompatible with DNS
if !dnsNameRe.MatchString(service.Service) {
a.logger.Printf("[WARN] Service name %q will not be discoverable "+
"via DNS due to invalid characters. Valid characters include "+
"all alpha-numerics and dashes.", service.Service)
}
// Warn if any tags are incompatible with DNS
for _, tag := range service.Tags {
if !dnsNameRe.MatchString(tag) {
a.logger.Printf("[DEBUG] Service tag %q will not be discoverable "+
"via DNS due to invalid characters. Valid characters include "+
"all alpha-numerics and dashes.", tag)
}
}
// Pause the service syncs during modification
a.PauseSync()
defer a.ResumeSync()
// Take a snapshot of the current state of checks (if any), and
// restore them before resuming anti-entropy.
snap := a.snapshotCheckState()
defer a.restoreCheckState(snap)
// Add the service
a.state.AddService(service, token)
// Persist the service to a file
if persist && !a.config.DevMode {
if err := a.persistService(service); err != nil {
return err
}
}
// Create an associated health check
for i, chkType := range chkTypes {
checkID := string(chkType.CheckID)
if checkID == "" {
checkID = fmt.Sprintf("service:%s", service.ID)
if len(chkTypes) > 1 {
checkID += fmt.Sprintf(":%d", i+1)
}
}
name := chkType.Name
if name == "" {
name = fmt.Sprintf("Service '%s' check", service.Service)
}
check := &structs.HealthCheck{
Node: a.config.NodeName,
CheckID: types.CheckID(checkID),
Name: name,
Status: api.HealthCritical,
Notes: chkType.Notes,
ServiceID: service.ID,
ServiceName: service.Service,
}
if chkType.Status != "" {
check.Status = chkType.Status
}
if err := a.AddCheck(check, chkType, persist, token); err != nil {
return err
}
}
return nil
}
// RemoveService is used to remove a service entry.
// The agent will make a best effort to ensure it is deregistered
func (a *Agent) RemoveService(serviceID string, persist bool) error {
// Protect "consul" service from deletion by a user
if _, ok := a.delegate.(*consul.Server); ok && serviceID == consul.ConsulServiceID {
return fmt.Errorf(
"Deregistering the %s service is not allowed",
consul.ConsulServiceID)
}
// Validate ServiceID
if serviceID == "" {
return fmt.Errorf("ServiceID missing")
}
// Remove service immediately
if err := a.state.RemoveService(serviceID); err != nil {
a.logger.Printf("[WARN] agent: Failed to deregister service %q: %s", serviceID, err)
return nil
}
// Remove the service from the data dir
if persist {
if err := a.purgeService(serviceID); err != nil {
return err
}
}
// Deregister any associated health checks
for checkID, health := range a.state.Checks() {
if health.ServiceID != serviceID {
continue
}
if err := a.RemoveCheck(checkID, persist); err != nil {
return err
}
}
log.Printf("[DEBUG] agent: removed service %q", serviceID)
return nil
}
// AddCheck is used to add a health check to the agent.
// This entry is persistent and the agent will make a best effort to
// ensure it is registered. The Check may include a CheckType which
// is used to automatically update the check status
func (a *Agent) AddCheck(check *structs.HealthCheck, chkType *CheckType, persist bool, token string) error {
if check.CheckID == "" {
return fmt.Errorf("CheckID missing")
}
if chkType != nil && !chkType.Valid() {
return fmt.Errorf("Check type is not valid")
}
if check.ServiceID != "" {
svc, ok := a.state.Services()[check.ServiceID]
if !ok {
return fmt.Errorf("ServiceID %q does not exist", check.ServiceID)
}
check.ServiceName = svc.Service
}
a.checkLock.Lock()
defer a.checkLock.Unlock()
// Check if already registered
if chkType != nil {
if chkType.IsTTL() {
if existing, ok := a.checkTTLs[check.CheckID]; ok {
existing.Stop()
}
ttl := &CheckTTL{
Notify: &a.state,
CheckID: check.CheckID,
TTL: chkType.TTL,
Logger: a.logger,
}
// Restore persisted state, if any
if err := a.loadCheckState(check); err != nil {
a.logger.Printf("[WARN] agent: failed restoring state for check %q: %s",
check.CheckID, err)
}
ttl.Start()
a.checkTTLs[check.CheckID] = ttl
} else if chkType.IsHTTP() {
if existing, ok := a.checkHTTPs[check.CheckID]; ok {
existing.Stop()
}
if chkType.Interval < MinInterval {
a.logger.Println(fmt.Sprintf("[WARN] agent: check '%s' has interval below minimum of %v",
check.CheckID, MinInterval))
chkType.Interval = MinInterval
}
http := &CheckHTTP{
Notify: &a.state,
CheckID: check.CheckID,
HTTP: chkType.HTTP,
Header: chkType.Header,
Method: chkType.Method,
Interval: chkType.Interval,
Timeout: chkType.Timeout,
Logger: a.logger,
TLSSkipVerify: chkType.TLSSkipVerify,
}
http.Start()
a.checkHTTPs[check.CheckID] = http
} else if chkType.IsTCP() {
if existing, ok := a.checkTCPs[check.CheckID]; ok {
existing.Stop()
}
if chkType.Interval < MinInterval {
a.logger.Println(fmt.Sprintf("[WARN] agent: check '%s' has interval below minimum of %v",
check.CheckID, MinInterval))
chkType.Interval = MinInterval
}
tcp := &CheckTCP{
Notify: &a.state,
CheckID: check.CheckID,
TCP: chkType.TCP,
Interval: chkType.Interval,
Timeout: chkType.Timeout,
Logger: a.logger,
}
tcp.Start()
a.checkTCPs[check.CheckID] = tcp
} else if chkType.IsDocker() {
if existing, ok := a.checkDockers[check.CheckID]; ok {
existing.Stop()
}
if chkType.Interval < MinInterval {
a.logger.Println(fmt.Sprintf("[WARN] agent: check '%s' has interval below minimum of %v",
check.CheckID, MinInterval))
chkType.Interval = MinInterval
}
dockerCheck := &CheckDocker{
Notify: &a.state,
CheckID: check.CheckID,
DockerContainerID: chkType.DockerContainerID,
Shell: chkType.Shell,
Script: chkType.Script,
Interval: chkType.Interval,
Logger: a.logger,
}
if err := dockerCheck.Init(); err != nil {
return err
}
dockerCheck.Start()
a.checkDockers[check.CheckID] = dockerCheck
} else if chkType.IsMonitor() {
if existing, ok := a.checkMonitors[check.CheckID]; ok {
existing.Stop()
}
if chkType.Interval < MinInterval {
a.logger.Println(fmt.Sprintf("[WARN] agent: check '%s' has interval below minimum of %v",
check.CheckID, MinInterval))
chkType.Interval = MinInterval
}
monitor := &CheckMonitor{
Notify: &a.state,
CheckID: check.CheckID,
Script: chkType.Script,
Interval: chkType.Interval,
Timeout: chkType.Timeout,
Logger: a.logger,
}
monitor.Start()
a.checkMonitors[check.CheckID] = monitor
} else {
return fmt.Errorf("Check type is not valid")
}
if chkType.DeregisterCriticalServiceAfter > 0 {
timeout := chkType.DeregisterCriticalServiceAfter
if timeout < a.config.CheckDeregisterIntervalMin {
timeout = a.config.CheckDeregisterIntervalMin
a.logger.Println(fmt.Sprintf("[WARN] agent: check '%s' has deregister interval below minimum of %v",
check.CheckID, a.config.CheckDeregisterIntervalMin))
}
a.checkReapAfter[check.CheckID] = timeout
} else {
delete(a.checkReapAfter, check.CheckID)
}
}
// Add to the local state for anti-entropy
a.state.AddCheck(check, token)
// Persist the check
if persist && !a.config.DevMode {
return a.persistCheck(check, chkType)
}
return nil
}
// RemoveCheck is used to remove a health check.
// The agent will make a best effort to ensure it is deregistered
func (a *Agent) RemoveCheck(checkID types.CheckID, persist bool) error {
// Validate CheckID
if checkID == "" {
return fmt.Errorf("CheckID missing")
}
// Add to the local state for anti-entropy
a.state.RemoveCheck(checkID)
a.checkLock.Lock()
defer a.checkLock.Unlock()
// Stop any monitors
delete(a.checkReapAfter, checkID)
if check, ok := a.checkMonitors[checkID]; ok {
check.Stop()
delete(a.checkMonitors, checkID)
}
if check, ok := a.checkHTTPs[checkID]; ok {
check.Stop()
delete(a.checkHTTPs, checkID)
}
if check, ok := a.checkTCPs[checkID]; ok {
check.Stop()
delete(a.checkTCPs, checkID)
}
if check, ok := a.checkTTLs[checkID]; ok {
check.Stop()
delete(a.checkTTLs, checkID)
}
if persist {
if err := a.purgeCheck(checkID); err != nil {
return err
}
if err := a.purgeCheckState(checkID); err != nil {
return err
}
}
a.logger.Printf("[DEBUG] agent: removed check %q", checkID)
return nil
}
// updateTTLCheck is used to update the status of a TTL check via the Agent API.
func (a *Agent) updateTTLCheck(checkID types.CheckID, status, output string) error {
a.checkLock.Lock()
defer a.checkLock.Unlock()
// Grab the TTL check.
check, ok := a.checkTTLs[checkID]
if !ok {
return fmt.Errorf("CheckID %q does not have associated TTL", checkID)
}
// Set the status through CheckTTL to reset the TTL.
check.SetStatus(status, output)
// We don't write any files in dev mode so bail here.
if a.config.DevMode {
return nil
}
// Persist the state so the TTL check can come up in a good state after
// an agent restart, especially with long TTL values.
if err := a.persistCheckState(check, status, output); err != nil {
return fmt.Errorf("failed persisting state for check %q: %s", checkID, err)
}
return nil
}
// persistCheckState is used to record the check status into the data dir.
// This allows the state to be restored on a later agent start. Currently
// only useful for TTL based checks.
func (a *Agent) persistCheckState(check *CheckTTL, status, output string) error {
// Create the persisted state
state := persistedCheckState{
CheckID: check.CheckID,
Status: status,
Output: output,
Expires: time.Now().Add(check.TTL).Unix(),
}
// Encode the state
buf, err := json.Marshal(state)
if err != nil {
return err
}
// Create the state dir if it doesn't exist
dir := filepath.Join(a.config.DataDir, checkStateDir)
if err := os.MkdirAll(dir, 0700); err != nil {
return fmt.Errorf("failed creating check state dir %q: %s", dir, err)
}
// Write the state to the file
file := filepath.Join(dir, checkIDHash(check.CheckID))
// Create temp file in same dir, to make more likely atomic
tempFile := file + ".tmp"
// persistCheckState is called frequently, so don't use writeFileAtomic to avoid calling fsync here
if err := ioutil.WriteFile(tempFile, buf, 0600); err != nil {
return fmt.Errorf("failed writing temp file %q: %s", tempFile, err)
}
if err := os.Rename(tempFile, file); err != nil {
return fmt.Errorf("failed to rename temp file from %q to %q: %s", tempFile, file, err)
}
return nil
}
// loadCheckState is used to restore the persisted state of a check.
func (a *Agent) loadCheckState(check *structs.HealthCheck) error {
// Try to read the persisted state for this check
file := filepath.Join(a.config.DataDir, checkStateDir, checkIDHash(check.CheckID))
buf, err := ioutil.ReadFile(file)
if err != nil {
if os.IsNotExist(err) {
return nil
}
return fmt.Errorf("failed reading file %q: %s", file, err)
}
// Decode the state data
var p persistedCheckState
if err := json.Unmarshal(buf, &p); err != nil {
a.logger.Printf("[ERR] agent: failed decoding check state: %s", err)
return a.purgeCheckState(check.CheckID)
}
// Check if the state has expired
if time.Now().Unix() >= p.Expires {
a.logger.Printf("[DEBUG] agent: check state expired for %q, not restoring", check.CheckID)
return a.purgeCheckState(check.CheckID)
}
// Restore the fields from the state
check.Output = p.Output
check.Status = p.Status
return nil
}
// purgeCheckState is used to purge the state of a check from the data dir
func (a *Agent) purgeCheckState(checkID types.CheckID) error {
file := filepath.Join(a.config.DataDir, checkStateDir, checkIDHash(checkID))
err := os.Remove(file)
if os.IsNotExist(err) {
return nil
}
return err
}
func (a *Agent) GossipEncrypted() bool {
return a.delegate.Encrypted()
}
// Stats is used to get various debugging state from the sub-systems
func (a *Agent) Stats() map[string]map[string]string {
toString := func(v uint64) string {
return strconv.FormatUint(v, 10)
}
stats := a.delegate.Stats()
stats["agent"] = map[string]string{
"check_monitors": toString(uint64(len(a.checkMonitors))),
"check_ttls": toString(uint64(len(a.checkTTLs))),
"checks": toString(uint64(len(a.state.checks))),
"services": toString(uint64(len(a.state.services))),
}
revision := a.config.Revision
if len(revision) > 8 {
revision = revision[:8]
}
stats["build"] = map[string]string{
"revision": revision,
"version": a.config.Version,
"prerelease": a.config.VersionPrerelease,
}
return stats
}
// storePid is used to write out our PID to a file if necessary
func (a *Agent) storePid() error {
// Quit fast if no pidfile
pidPath := a.config.PidFile
if pidPath == "" {
return nil
}
// Open the PID file
pidFile, err := os.OpenFile(pidPath, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0666)
if err != nil {
return fmt.Errorf("Could not open pid file: %v", err)
}
defer pidFile.Close()
// Write out the PID
pid := os.Getpid()
_, err = pidFile.WriteString(fmt.Sprintf("%d", pid))
if err != nil {
return fmt.Errorf("Could not write to pid file: %s", err)
}
return nil
}
// deletePid is used to delete our PID on exit
func (a *Agent) deletePid() error {
// Quit fast if no pidfile
pidPath := a.config.PidFile
if pidPath == "" {
return nil
}
stat, err := os.Stat(pidPath)
if err != nil {
return fmt.Errorf("Could not remove pid file: %s", err)
}
if stat.IsDir() {
return fmt.Errorf("Specified pid file path is directory")
}
err = os.Remove(pidPath)
if err != nil {
return fmt.Errorf("Could not remove pid file: %s", err)
}
return nil
}
// loadServices will load service definitions from configuration and persisted
// definitions on disk, and load them into the local agent.
func (a *Agent) loadServices(conf *Config) error {
// Register the services from config
for _, service := range conf.Services {
ns := service.NodeService()
chkTypes := service.CheckTypes()
if err := a.AddService(ns, chkTypes, false, service.Token); err != nil {
return fmt.Errorf("Failed to register service '%s': %v", service.ID, err)
}
}
// Load any persisted services
svcDir := filepath.Join(a.config.DataDir, servicesDir)
files, err := ioutil.ReadDir(svcDir)
if err != nil {
if os.IsNotExist(err) {
return nil
}
return fmt.Errorf("Failed reading services dir %q: %s", svcDir, err)
}
for _, fi := range files {
// Skip all dirs
if fi.IsDir() {
continue
}
// Open the file for reading
file := filepath.Join(svcDir, fi.Name())
fh, err := os.Open(file)
if err != nil {
return fmt.Errorf("failed opening service file %q: %s", file, err)
}
// Read the contents into a buffer
buf, err := ioutil.ReadAll(fh)
fh.Close()
if err != nil {
return fmt.Errorf("failed reading service file %q: %s", file, err)
}
// Try decoding the service definition
var p persistedService
if err := json.Unmarshal(buf, &p); err != nil {
// Backwards-compatibility for pre-0.5.1 persisted services
if err := json.Unmarshal(buf, &p.Service); err != nil {
return fmt.Errorf("failed decoding service file %q: %s", file, err)
}
}
serviceID := p.Service.ID
if _, ok := a.state.services[serviceID]; ok {
// Purge previously persisted service. This allows config to be
// preferred over services persisted from the API.
a.logger.Printf("[DEBUG] agent: service %q exists, not restoring from %q",
serviceID, file)
if err := a.purgeService(serviceID); err != nil {
return fmt.Errorf("failed purging service %q: %s", serviceID, err)
}
} else {
a.logger.Printf("[DEBUG] agent: restored service definition %q from %q",
serviceID, file)
if err := a.AddService(p.Service, nil, false, p.Token); err != nil {
return fmt.Errorf("failed adding service %q: %s", serviceID, err)
}
}
}
return nil
}
// unloadServices will deregister all services other than the 'consul' service
// known to the local agent.
func (a *Agent) unloadServices() error {
for _, service := range a.state.Services() {
if service.ID == consul.ConsulServiceID {
continue
}
if err := a.RemoveService(service.ID, false); err != nil {
return fmt.Errorf("Failed deregistering service '%s': %v", service.ID, err)
}
}
return nil
}
// loadChecks loads check definitions and/or persisted check definitions from
// disk and re-registers them with the local agent.
func (a *Agent) loadChecks(conf *Config) error {
// Register the checks from config
for _, check := range conf.Checks {
health := check.HealthCheck(conf.NodeName)
chkType := check.CheckType()
if err := a.AddCheck(health, chkType, false, check.Token); err != nil {
return fmt.Errorf("Failed to register check '%s': %v %v", check.Name, err, check)
}
}
// Load any persisted checks
checkDir := filepath.Join(a.config.DataDir, checksDir)
files, err := ioutil.ReadDir(checkDir)
if err != nil {
if os.IsNotExist(err) {
return nil
}
return fmt.Errorf("Failed reading checks dir %q: %s", checkDir, err)
}
for _, fi := range files {
// Ignore dirs - we only care about the check definition files
if fi.IsDir() {
continue
}
// Open the file for reading
file := filepath.Join(checkDir, fi.Name())
fh, err := os.Open(file)
if err != nil {
return fmt.Errorf("Failed opening check file %q: %s", file, err)
}
// Read the contents into a buffer
buf, err := ioutil.ReadAll(fh)
fh.Close()
if err != nil {
return fmt.Errorf("failed reading check file %q: %s", file, err)
}
// Decode the check
var p persistedCheck
if err := json.Unmarshal(buf, &p); err != nil {
return fmt.Errorf("Failed decoding check file %q: %s", file, err)
}
checkID := p.Check.CheckID
if _, ok := a.state.checks[checkID]; ok {
// Purge previously persisted check. This allows config to be
// preferred over persisted checks from the API.
a.logger.Printf("[DEBUG] agent: check %q exists, not restoring from %q",
checkID, file)
if err := a.purgeCheck(checkID); err != nil {
return fmt.Errorf("Failed purging check %q: %s", checkID, err)
}
} else {
// Default check to critical to avoid placing potentially unhealthy
// services into the active pool
p.Check.Status = api.HealthCritical
if err := a.AddCheck(p.Check, p.ChkType, false, p.Token); err != nil {
// Purge the check if it is unable to be restored.
a.logger.Printf("[WARN] agent: Failed to restore check %q: %s",
checkID, err)
if err := a.purgeCheck(checkID); err != nil {
return fmt.Errorf("Failed purging check %q: %s", checkID, err)
}
}
a.logger.Printf("[DEBUG] agent: restored health check %q from %q",
p.Check.CheckID, file)
}
}
return nil
}
// unloadChecks will deregister all checks known to the local agent.
func (a *Agent) unloadChecks() error {
for _, check := range a.state.Checks() {
if err := a.RemoveCheck(check.CheckID, false); err != nil {
return fmt.Errorf("Failed deregistering check '%s': %s", check.CheckID, err)
}
}
return nil
}
// snapshotCheckState is used to snapshot the current state of the health
// checks. This is done before we reload our checks, so that we can properly
// restore into the same state.
func (a *Agent) snapshotCheckState() map[types.CheckID]*structs.HealthCheck {
return a.state.Checks()
}
// restoreCheckState is used to reset the health state based on a snapshot.
// This is done after we finish the reload to avoid any unnecessary flaps
// in health state and potential session invalidations.
func (a *Agent) restoreCheckState(snap map[types.CheckID]*structs.HealthCheck) {
for id, check := range snap {
a.state.UpdateCheck(id, check.Status, check.Output)
}
}
// loadMetadata loads node metadata fields from the agent config and
// updates them on the local agent.
func (a *Agent) loadMetadata(conf *Config) error {
a.state.Lock()
defer a.state.Unlock()
for key, value := range conf.Meta {
a.state.metadata[key] = value
}
a.state.changeMade()
return nil
}
// unloadMetadata resets the local metadata state
func (a *Agent) unloadMetadata() {
a.state.Lock()
defer a.state.Unlock()
a.state.metadata = make(map[string]string)
}
// serviceMaintCheckID returns the ID of a given service's maintenance check
func serviceMaintCheckID(serviceID string) types.CheckID {
return types.CheckID(structs.ServiceMaintPrefix + serviceID)
}
// EnableServiceMaintenance will register a false health check against the given
// service ID with critical status. This will exclude the service from queries.
func (a *Agent) EnableServiceMaintenance(serviceID, reason, token string) error {
service, ok := a.state.Services()[serviceID]
if !ok {
return fmt.Errorf("No service registered with ID %q", serviceID)
}
// Check if maintenance mode is not already enabled
checkID := serviceMaintCheckID(serviceID)
if _, ok := a.state.Checks()[checkID]; ok {
return nil
}
// Use default notes if no reason provided
if reason == "" {
reason = defaultServiceMaintReason
}
// Create and register the critical health check
check := &structs.HealthCheck{
Node: a.config.NodeName,
CheckID: checkID,
Name: "Service Maintenance Mode",
Notes: reason,
ServiceID: service.ID,
ServiceName: service.Service,
Status: api.HealthCritical,
}
a.AddCheck(check, nil, true, token)
a.logger.Printf("[INFO] agent: Service %q entered maintenance mode", serviceID)
return nil
}
// DisableServiceMaintenance will deregister the fake maintenance mode check
// if the service has been marked as in maintenance.
func (a *Agent) DisableServiceMaintenance(serviceID string) error {
if _, ok := a.state.Services()[serviceID]; !ok {
return fmt.Errorf("No service registered with ID %q", serviceID)
}
// Check if maintenance mode is enabled
checkID := serviceMaintCheckID(serviceID)
if _, ok := a.state.Checks()[checkID]; !ok {
return nil
}
// Deregister the maintenance check
a.RemoveCheck(checkID, true)
a.logger.Printf("[INFO] agent: Service %q left maintenance mode", serviceID)
return nil
}
// EnableNodeMaintenance places a node into maintenance mode.
func (a *Agent) EnableNodeMaintenance(reason, token string) {
// Ensure node maintenance is not already enabled
if _, ok := a.state.Checks()[structs.NodeMaint]; ok {
return
}
// Use a default notes value
if reason == "" {
reason = defaultNodeMaintReason
}
// Create and register the node maintenance check
check := &structs.HealthCheck{
Node: a.config.NodeName,
CheckID: structs.NodeMaint,
Name: "Node Maintenance Mode",
Notes: reason,
Status: api.HealthCritical,
}
a.AddCheck(check, nil, true, token)
a.logger.Printf("[INFO] agent: Node entered maintenance mode")
}
// DisableNodeMaintenance removes a node from maintenance mode
func (a *Agent) DisableNodeMaintenance() {
if _, ok := a.state.Checks()[structs.NodeMaint]; !ok {
return
}
a.RemoveCheck(structs.NodeMaint, true)
a.logger.Printf("[INFO] agent: Node left maintenance mode")
}
// InjectEndpoint overrides the given endpoint with a substitute one. Note
// that not all agent methods use this mechanism, and that is should only
// be used for testing.
func (a *Agent) InjectEndpoint(endpoint string, handler interface{}) error {
srv, ok := a.delegate.(*consul.Server)
if !ok {
return fmt.Errorf("agent must be a server")
}
if err := srv.InjectEndpoint(handler); err != nil {
return err
}
name := reflect.Indirect(reflect.ValueOf(handler)).Type().Name()
a.endpointsLock.Lock()
a.endpoints[endpoint] = name
a.endpointsLock.Unlock()
a.logger.Printf("[WARN] agent: endpoint injected; this should only be used for testing")
return nil
}
// getEndpoint returns the endpoint name to use for the given endpoint,
// which may be overridden.
func (a *Agent) getEndpoint(endpoint string) string {
a.endpointsLock.RLock()
defer a.endpointsLock.RUnlock()
if override, ok := a.endpoints[endpoint]; ok {
return override
}
return endpoint
}
func (a *Agent) ReloadConfig(newCfg *Config) (bool, error) {
var errs error
// Bulk update the services and checks
a.PauseSync()
defer a.ResumeSync()
// Snapshot the current state, and restore it afterwards
snap := a.snapshotCheckState()
defer a.restoreCheckState(snap)
// First unload all checks, services, and metadata. This lets us begin the reload
// with a clean slate.
if err := a.unloadServices(); err != nil {
errs = multierror.Append(errs, fmt.Errorf("Failed unloading services: %s", err))
return false, errs
}
if err := a.unloadChecks(); err != nil {
errs = multierror.Append(errs, fmt.Errorf("Failed unloading checks: %s", err))
return false, errs
}
a.unloadMetadata()
// Reload service/check definitions and metadata.
if err := a.loadServices(newCfg); err != nil {
errs = multierror.Append(errs, fmt.Errorf("Failed reloading services: %s", err))
return false, errs
}
if err := a.loadChecks(newCfg); err != nil {
errs = multierror.Append(errs, fmt.Errorf("Failed reloading checks: %s", err))
return false, errs
}
if err := a.loadMetadata(newCfg); err != nil {
errs = multierror.Append(errs, fmt.Errorf("Failed reloading metadata: %s", err))
return false, errs
}
// Get the new client listener addr
httpAddr, err := newCfg.ClientListener(a.config.Addresses.HTTP, a.config.Ports.HTTP)
if err != nil {
errs = multierror.Append(errs, fmt.Errorf("Failed to determine HTTP address: %v", err))
}
// Deregister the old watches
for _, wp := range a.config.WatchPlans {
wp.Stop()
}
// Register the new watches
for _, wp := range newCfg.WatchPlans {
go func(wp *watch.Plan) {
wp.Handler = makeWatchHandler(a.LogOutput, wp.Exempt["handler"])
wp.LogOutput = a.LogOutput
if err := wp.Run(httpAddr.String()); err != nil {
errs = multierror.Append(errs, fmt.Errorf("Error running watch: %v", err))
}
}(wp)
}
return true, errs
}