Fixing merge conflict

command/agent/agent.go

@@ -2,15 +2,16 @@ package agent
 
 import (
 	"fmt"
-	"github.com/hashicorp/consul/consul"
-	"github.com/hashicorp/consul/consul/structs"
-	"github.com/hashicorp/serf/serf"
 	"io"
 	"log"
 	"net"
 	"os"
 	"strconv"
 	"sync"
+
+	"github.com/hashicorp/consul/consul"
+	"github.com/hashicorp/consul/consul/structs"
+	"github.com/hashicorp/serf/serf"
 )
 
 /*
@@ -174,6 +175,9 @@ func (a *Agent) consulConfig() *consul.Config {
 	if a.config.RejoinAfterLeave {
 		base.RejoinAfterLeave = true
 	}
+	if a.config.Expect != 0 {
+		base.Expect = a.config.Expect
+	}
 	if a.config.Protocol > 0 {
 		base.ProtocolVersion = uint8(a.config.Protocol)
 	}

command/agent/command.go

@@ -3,10 +3,6 @@ package agent
 import (
 	"flag"
 	"fmt"
-	"github.com/armon/go-metrics"
-	"github.com/hashicorp/go-syslog"
-	"github.com/hashicorp/logutils"
-	"github.com/mitchellh/cli"
 	"io"
 	"net"
 	"os"
@@ -16,6 +12,11 @@ import (
 	"strings"
 	"syscall"
 	"time"
+
+	"github.com/armon/go-metrics"
+	"github.com/hashicorp/go-syslog"
+	"github.com/hashicorp/logutils"
+	"github.com/mitchellh/cli"
 )
 
 // gracefulTimeout controls how long we wait before forcefully terminating
@@ -62,6 +63,7 @@ func (c *Command) readConfig() *Config {
 
 	cmdFlags.BoolVar(&cmdConfig.Server, "server", false, "run agent as server")
 	cmdFlags.BoolVar(&cmdConfig.Bootstrap, "bootstrap", false, "enable server bootstrap mode")
+	cmdFlags.IntVar(&cmdConfig.Expect, "expect", 0, "enable automatic bootstrap via expect mode")
 
 	cmdFlags.StringVar(&cmdConfig.ClientAddr, "client", "", "address to bind client listeners to (DNS, HTTP, RPC)")
 	cmdFlags.StringVar(&cmdConfig.BindAddr, "bind", "", "address to bind server listeners to")
@@ -127,6 +129,30 @@ func (c *Command) readConfig() *Config {
 		return nil
 	}
 
+	// Expect can only work when acting as a server
+	if config.Expect != 0 && !config.Server {
+		c.Ui.Error("Expect mode cannot be enabled when server mode is not enabled")
+		return nil
+	}
+
+	// Expect & Bootstrap are mutually exclusive
+	if config.Expect != 0 && config.Bootstrap {
+		c.Ui.Error("Bootstrap cannot be provided with an expected server count")
+		return nil
+	}
+
+	// Warn if we are in expect mode
+	if config.Expect != 0 {
+		if config.Expect == 1 {
+			// just use bootstrap mode
+			c.Ui.Error("WARNING: Expect Mode is specified as 1; this is the same as Bootstrap mode.")
+			config.Expect = 0
+			config.Bootstrap = true
+		} else {
+			c.Ui.Error(fmt.Sprintf("WARNING: Expect Mode enabled, looking for %v servers!", config.Expect))
+		}
+	}
+
 	// Warn if we are in bootstrap mode
 	if config.Bootstrap {
 		c.Ui.Error("WARNING: Bootstrap mode enabled! Do not enable unless necessary")
@@ -524,6 +550,7 @@ Options:
                            order.
   -data-dir=path           Path to a data directory to store agent state
   -dc=east-aws             Datacenter of the agent
+  -expect=0                Sets server to expect bootstrap mode.
   -join=1.2.3.4            Address of an agent to join at start time.
                            Can be specified multiple times.
   -log-level=info          Log level of the agent.

command/agent/config.go

@@ -4,8 +4,6 @@ import (
 	"encoding/base64"
 	"encoding/json"
 	"fmt"
-	"github.com/hashicorp/consul/consul"
-	"github.com/mitchellh/mapstructure"
 	"io"
 	"net"
 	"os"
@@ -13,6 +11,9 @@ import (
 	"sort"
 	"strings"
 	"time"
+
+	"github.com/hashicorp/consul/consul"
+	"github.com/mitchellh/mapstructure"
 )
 
 // Ports is used to simplify the configuration by
@@ -64,6 +65,10 @@ type Config struct {
 	// permits that node to elect itself leader
 	Bootstrap bool `mapstructure:"bootstrap"`
 
+	// Expect tries to automatically bootstrap the Consul cluster,
+	// by witholding peers until enough servers join.
+	Expect int `mapstructure:"expect"`
+
 	// Server controls if this agent acts like a Consul server,
 	// or merely as a client. Servers have more state, take part
 	// in leader election, etc.
@@ -219,6 +224,7 @@ type dirEnts []os.FileInfo
 func DefaultConfig() *Config {
 	return &Config{
 		Bootstrap:  false,
+		Expect:     0,
 		Server:     false,
 		Datacenter: consul.DefaultDC,
 		Domain:     "consul.",
@@ -449,6 +455,9 @@ func MergeConfig(a, b *Config) *Config {
 	if b.Bootstrap {
 		result.Bootstrap = true
 	}
+	if b.Expect != 0 {
+		result.Expect = b.Expect
+	}
 	if b.Datacenter != "" {
 		result.Datacenter = b.Datacenter
 	}

command/agent/config_test.go

@@ -93,6 +93,21 @@ func TestDecodeConfig(t *testing.T) {
 		t.Fatalf("bad: %#v", config)
 	}
 
+	// Expect bootstrap
+	input = `{"server": true, "expect": 3}`
+	config, err = DecodeConfig(bytes.NewReader([]byte(input)))
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	if !config.Server {
+		t.Fatalf("bad: %#v", config)
+	}
+
+	if config.Expect != 3 {
+		t.Fatalf("bad: %#v", config)
+	}
+
 	// DNS setup
 	input = `{"ports": {"dns": 8500}, "recursor": "8.8.8.8", "domain": "foobar"}`
 	config, err = DecodeConfig(bytes.NewReader([]byte(input)))
@@ -426,6 +441,7 @@ func TestDecodeConfig_Check(t *testing.T) {
 func TestMergeConfig(t *testing.T) {
 	a := &Config{
 		Bootstrap:              false,
+		Expect:                 0,
 		Datacenter:             "dc1",
 		DataDir:                "/tmp/foo",
 		DNSRecursor:            "127.0.0.1:1001",
@@ -444,6 +460,7 @@ func TestMergeConfig(t *testing.T) {
 
 	b := &Config{
 		Bootstrap:   true,
+		Expect:      3,
 		Datacenter:  "dc2",
 		DataDir:     "/tmp/bar",
 		DNSRecursor: "127.0.0.2:1001",

consul/config.go

@@ -44,6 +44,11 @@ type Config struct {
 	// other nodes being present
 	Bootstrap bool
 
+	// Expect mode is used to automatically bring up a collection of
+	// Consul servers. This can be used to automatically bring up a collection
+	// of nodes.
+	Expect int
+
 	// Datacenter is the datacenter this Consul server represents
 	Datacenter string
 

consul/leader.go

@@ -1,13 +1,14 @@
 package consul
 
 import (
+	"net"
+	"strconv"
+	"time"
+
 	"github.com/armon/go-metrics"
 	"github.com/hashicorp/consul/consul/structs"
 	"github.com/hashicorp/raft"
 	"github.com/hashicorp/serf/serf"
-	"net"
-	"strconv"
-	"time"
 )
 
 const (

consul/serf.go

@@ -1,8 +1,10 @@
 package consul
 
 import (
-	"github.com/hashicorp/serf/serf"
+	"net"
 	"strings"
+
+	"github.com/hashicorp/serf/serf"
 )
 
 const (
@@ -149,6 +151,41 @@ func (s *Server) nodeJoin(me serf.MemberEvent, wan bool) {
 			s.localConsuls[parts.Addr.String()] = parts
 			s.localLock.Unlock()
 		}
+
+		// If we're still expecting, and they are too, check servers.
+		if s.config.Expect != 0 && parts.Expect != 0 {
+			index, err := s.raftStore.LastIndex()
+			if err == nil && index == 0 {
+				members := s.serfLAN.Members()
+				addrs := make([]net.Addr, 0)
+				for _, member := range members {
+					valid, p := isConsulServer(member)
+					if valid && p.Datacenter == parts.Datacenter {
+						if p.Expect != parts.Expect {
+							s.logger.Printf("[ERR] consul: '%v' and '%v' have different expect values. All expect nodes should have the same value, will never leave expect mode", m.Name, member.Name)
+							return
+						} else {
+							addrs = append(addrs, &net.TCPAddr{IP: member.Addr, Port: p.Port})
+						}
+					}
+				}
+
+				if len(addrs) >= s.config.Expect {
+					// we have enough nodes, set peers.
+
+					future := s.raft.SetPeers(addrs)
+
+					if err := future.Error(); err != nil {
+						s.logger.Printf("[ERR] consul: failed to leave expect mode and set peers: %v", err)
+					} else {
+						// we've left expect mode, don't enter this again
+						s.config.Expect = 0
+					}
+				}
+			} else if err != nil {
+				s.logger.Printf("[ERR] consul: error retrieving index: %v", err)
+			}
+		}
 	}
 }
 

consul/server.go

@@ -4,9 +4,6 @@ import (
 	"crypto/tls"
 	"errors"
 	"fmt"
-	"github.com/hashicorp/raft"
-	"github.com/hashicorp/raft-mdb"
-	"github.com/hashicorp/serf/serf"
 	"log"
 	"net"
 	"net/rpc"
@@ -17,6 +14,10 @@ import (
 	"strconv"
 	"sync"
 	"time"
+
+	"github.com/hashicorp/raft"
+	"github.com/hashicorp/raft-mdb"
+	"github.com/hashicorp/serf/serf"
 )
 
 // These are the protocol versions that Consul can _understand_. These are
@@ -233,6 +234,9 @@ func (s *Server) setupSerf(conf *serf.Config, ch chan serf.Event, path string, w
 	if s.config.Bootstrap {
 		conf.Tags["bootstrap"] = "1"
 	}
+	if s.config.Expect != 0 {
+		conf.Tags["expect"] = fmt.Sprintf("%d", s.config.Expect)
+	}
 	conf.MemberlistConfig.LogOutput = s.config.LogOutput
 	conf.LogOutput = s.config.LogOutput
 	conf.EventCh = ch

consul/server_test.go

@@ -3,12 +3,13 @@ package consul
 import (
 	"errors"
 	"fmt"
-	"github.com/hashicorp/consul/testutil"
 	"io/ioutil"
 	"net"
 	"os"
 	"testing"
 	"time"
+
+	"github.com/hashicorp/consul/testutil"
 )
 
 var nextPort = 15000
@@ -87,6 +88,19 @@ func testServerDCBootstrap(t *testing.T, dc string, bootstrap bool) (string, *Se
 	return dir, server
 }
 
+func testServerDCExpect(t *testing.T, dc string, expect int) (string, *Server) {
+	name := fmt.Sprintf("Node %d", getPort())
+	dir, config := testServerConfig(t, name)
+	config.Datacenter = dc
+	config.Bootstrap = false
+	config.Expect = expect
+	server, err := NewServer(config)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	return dir, server
+}
+
 func TestServer_StartStop(t *testing.T) {
 	dir := tmpDir(t)
 	defer os.RemoveAll(dir)
@@ -304,3 +318,147 @@ func TestServer_JoinLAN_TLS(t *testing.T) {
 		t.Fatalf("no peer established")
 	})
 }
+
+func TestServer_Expect(t *testing.T) {
+	// all test servers should be in expect=3 mode
+	dir1, s1 := testServerDCExpect(t, "dc1", 3)
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+
+	dir2, s2 := testServerDCExpect(t, "dc1", 3)
+	defer os.RemoveAll(dir2)
+	defer s2.Shutdown()
+
+	dir3, s3 := testServerDCExpect(t, "dc1", 3)
+	defer os.RemoveAll(dir3)
+	defer s3.Shutdown()
+
+	// Try to join
+	addr := fmt.Sprintf("127.0.0.1:%d",
+		s1.config.SerfLANConfig.MemberlistConfig.BindPort)
+	if _, err := s2.JoinLAN([]string{addr}); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	var p1 []net.Addr
+	var p2 []net.Addr
+
+	// should have no peers yet
+	testutil.WaitForResult(func() (bool, error) {
+		p1, _ = s1.raftPeers.Peers()
+		return len(p1) == 0, errors.New(fmt.Sprintf("%v", p1))
+	}, func(err error) {
+		t.Fatalf("should have 0 peers: %v", err)
+	})
+
+	testutil.WaitForResult(func() (bool, error) {
+		p2, _ = s2.raftPeers.Peers()
+		return len(p2) == 0, errors.New(fmt.Sprintf("%v", p2))
+	}, func(err error) {
+		t.Fatalf("should have 0 peers: %v", err)
+	})
+
+	// join the third node
+	if _, err := s3.JoinLAN([]string{addr}); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	var p3 []net.Addr
+
+	// should now have all three peers
+	testutil.WaitForResult(func() (bool, error) {
+		p1, _ = s1.raftPeers.Peers()
+		return len(p1) == 3, errors.New(fmt.Sprintf("%v", p1))
+	}, func(err error) {
+		t.Fatalf("should have 3 peers: %v", err)
+	})
+
+	testutil.WaitForResult(func() (bool, error) {
+		p2, _ = s2.raftPeers.Peers()
+		return len(p2) == 3, errors.New(fmt.Sprintf("%v", p2))
+	}, func(err error) {
+		t.Fatalf("should have 3 peers: %v", err)
+	})
+
+	testutil.WaitForResult(func() (bool, error) {
+		p3, _ = s3.raftPeers.Peers()
+		return len(p3) == 3, errors.New(fmt.Sprintf("%v", p3))
+	}, func(err error) {
+		t.Fatalf("should have 3 peers: %v", err)
+	})
+
+	// check if there is one leader now
+	testutil.WaitForLeader(t, s1.RPC, "dc1")
+}
+
+func TestServer_BadExpect(t *testing.T) {
+	// this one is in expect=3 mode
+	dir1, s1 := testServerDCExpect(t, "dc1", 3)
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+
+	// this one is in expect=2 mode
+	dir2, s2 := testServerDCExpect(t, "dc1", 2)
+	defer os.RemoveAll(dir2)
+	defer s2.Shutdown()
+
+	// and this one is in expect=3 mode
+	dir3, s3 := testServerDCExpect(t, "dc1", 3)
+	defer os.RemoveAll(dir3)
+	defer s3.Shutdown()
+
+	// Try to join
+	addr := fmt.Sprintf("127.0.0.1:%d",
+		s1.config.SerfLANConfig.MemberlistConfig.BindPort)
+	if _, err := s2.JoinLAN([]string{addr}); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	var p1 []net.Addr
+	var p2 []net.Addr
+
+	// should have no peers yet
+	testutil.WaitForResult(func() (bool, error) {
+		p1, _ = s1.raftPeers.Peers()
+		return len(p1) == 0, errors.New(fmt.Sprintf("%v", p1))
+	}, func(err error) {
+		t.Fatalf("should have 0 peers: %v", err)
+	})
+
+	testutil.WaitForResult(func() (bool, error) {
+		p2, _ = s2.raftPeers.Peers()
+		return len(p2) == 0, errors.New(fmt.Sprintf("%v", p2))
+	}, func(err error) {
+		t.Fatalf("should have 0 peers: %v", err)
+	})
+
+	// join the third node
+	if _, err := s3.JoinLAN([]string{addr}); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	var p3 []net.Addr
+
+	// should still have no peers (because s2 is in expect=2 mode)
+	testutil.WaitForResult(func() (bool, error) {
+		p1, _ = s1.raftPeers.Peers()
+		return len(p1) == 0, errors.New(fmt.Sprintf("%v", p1))
+	}, func(err error) {
+		t.Fatalf("should have 0 peers: %v", err)
+	})
+
+	testutil.WaitForResult(func() (bool, error) {
+		p2, _ = s2.raftPeers.Peers()
+		return len(p2) == 0, errors.New(fmt.Sprintf("%v", p2))
+	}, func(err error) {
+		t.Fatalf("should have 0 peers: %v", err)
+	})
+
+	testutil.WaitForResult(func() (bool, error) {
+		p3, _ = s3.raftPeers.Peers()
+		return len(p3) == 0, errors.New(fmt.Sprintf("%v", p3))
+	}, func(err error) {
+		t.Fatalf("should have 0 peers: %v", err)
+	})
+
+}

consul/util.go

@@ -4,12 +4,13 @@ import (
 	crand "crypto/rand"
 	"encoding/binary"
 	"fmt"
-	"github.com/hashicorp/serf/serf"
 	"net"
 	"os"
 	"path/filepath"
 	"runtime"
 	"strconv"
+
+	"github.com/hashicorp/serf/serf"
 )
 
 /*
@@ -26,6 +27,7 @@ type serverParts struct {
 	Datacenter string
 	Port       int
 	Bootstrap  bool
+	Expect     int
 	Version    int
 	Addr       net.Addr
 }
@@ -84,6 +86,16 @@ func isConsulServer(m serf.Member) (bool, *serverParts) {
 	datacenter := m.Tags["dc"]
 	_, bootstrap := m.Tags["bootstrap"]
 
+	expect := 0
+	expect_str, ok := m.Tags["expect"]
+	var err error
+	if ok {
+		expect, err = strconv.Atoi(expect_str)
+		if err != nil {
+			return false, nil
+		}
+	}
+
 	port_str := m.Tags["port"]
 	port, err := strconv.Atoi(port_str)
 	if err != nil {
@@ -103,6 +115,7 @@ func isConsulServer(m serf.Member) (bool, *serverParts) {
 		Datacenter: datacenter,
 		Port:       port,
 		Bootstrap:  bootstrap,
+		Expect:     expect,
 		Addr:       addr,
 		Version:    vsn,
 	}

consul/util_test.go

@@ -1,10 +1,11 @@
 package consul
 
 import (
-	"github.com/hashicorp/serf/serf"
 	"net"
 	"regexp"
 	"testing"
+
+	"github.com/hashicorp/serf/serf"
 )
 
 func TestStrContains(t *testing.T) {
@@ -56,6 +57,9 @@ func TestIsConsulServer(t *testing.T) {
 	if parts.Bootstrap {
 		t.Fatalf("unexpected bootstrap")
 	}
+	if parts.Expect != 0 {
+		t.Fatalf("bad: %v", parts.Expect)
+	}
 	m.Tags["bootstrap"] = "1"
 	valid, parts = isConsulServer(m)
 	if !valid || !parts.Bootstrap {
@@ -67,6 +71,12 @@ func TestIsConsulServer(t *testing.T) {
 	if parts.Version != 1 {
 		t.Fatalf("bad: %v", parts)
 	}
+	m.Tags["expect"] = "3"
+	delete(m.Tags, "bootstrap")
+	valid, parts = isConsulServer(m)
+	if !valid || parts.Expect != 3 {
+		t.Fatalf("bad: %v", parts.Expect)
+	}
 }
 
 func TestIsConsulNode(t *testing.T) {