From 33afbfead648e04a9b86a996870d94140e75012f Mon Sep 17 00:00:00 2001
From: Xiang Li <xiang.li@coreos.com>
Date: Wed, 28 Jan 2015 14:07:07 -0800
Subject: [PATCH] etcdserver: remove the dep on metrics. first step towards
 removing metrics pkg from etcd.

---
 etcdserver/etcdhttp/client.go |  3 +--
 etcdserver/raft.go            | 17 +++++++++++++++++
 etcdserver/server.go          |  5 -----
 3 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/etcdserver/etcdhttp/client.go b/etcdserver/etcdhttp/client.go
index 39d0fadf0..2a393d336 100644
--- a/etcdserver/etcdhttp/client.go
+++ b/etcdserver/etcdhttp/client.go
@@ -35,7 +35,6 @@ import (
 	"github.com/coreos/etcd/etcdserver/etcdhttp/httptypes"
 	"github.com/coreos/etcd/etcdserver/etcdserverpb"
 	"github.com/coreos/etcd/etcdserver/stats"
-	"github.com/coreos/etcd/pkg/metrics"
 	"github.com/coreos/etcd/pkg/types"
 	"github.com/coreos/etcd/raft"
 	"github.com/coreos/etcd/store"
@@ -291,7 +290,7 @@ func serveStats(w http.ResponseWriter, r *http.Request) {
 	// TODO: getting one key or a prefix of keys based on path
 	fmt.Fprintf(w, "{\n")
 	first := true
-	metrics.Do(func(kv expvar.KeyValue) {
+	expvar.Do(func(kv expvar.KeyValue) {
 		if !first {
 			fmt.Fprintf(w, ",\n")
 		}
diff --git a/etcdserver/raft.go b/etcdserver/raft.go
index 0d7d5d001..02e8d61ec 100644
--- a/etcdserver/raft.go
+++ b/etcdserver/raft.go
@@ -16,6 +16,7 @@ package etcdserver
 
 import (
 	"encoding/json"
+	"expvar"
 	"log"
 	"os"
 	"sort"
@@ -31,6 +32,19 @@ import (
 	"github.com/coreos/etcd/wal/walpb"
 )
 
+var (
+	// indirection for expvar func interface
+	// expvar panics when publishing duplicate name
+	// expvar does not support remove a registered name
+	// so only register a func that calls raftStatus
+	// and change raftStatus as we need.
+	raftStatus func() raft.Status
+)
+
+func init() {
+	expvar.Publish("raft.status", expvar.Func(func() interface{} { return raftStatus() }))
+}
+
 type RaftTimer interface {
 	Index() uint64
 	Term() uint64
@@ -96,6 +110,7 @@ func startNode(cfg *ServerConfig, ids []types.ID) (id types.ID, n raft.Node, s *
 	log.Printf("etcdserver: start member %s in cluster %s", id, cfg.Cluster.ID())
 	s = raft.NewMemoryStorage()
 	n = raft.StartNode(uint64(id), peers, cfg.ElectionTicks, 1, s)
+	raftStatus = n.Status
 	return
 }
 
@@ -115,6 +130,7 @@ func restartNode(cfg *ServerConfig, snapshot *raftpb.Snapshot) (types.ID, raft.N
 	s.SetHardState(st)
 	s.Append(ents)
 	n := raft.RestartNode(uint64(id), cfg.ElectionTicks, 1, s, 0)
+	raftStatus = n.Status
 	return id, n, s, w
 }
 
@@ -156,6 +172,7 @@ func restartAsStandaloneNode(cfg *ServerConfig, snapshot *raftpb.Snapshot) (type
 	s.SetHardState(st)
 	s.Append(ents)
 	n := raft.RestartNode(uint64(id), cfg.ElectionTicks, 1, s, 0)
+	raftStatus = n.Status
 	return id, n, s, w
 }
 
diff --git a/etcdserver/server.go b/etcdserver/server.go
index cc8f527d5..8895d36cf 100644
--- a/etcdserver/server.go
+++ b/etcdserver/server.go
@@ -16,7 +16,6 @@ package etcdserver
 
 import (
 	"encoding/json"
-	"expvar"
 	"fmt"
 	"log"
 	"math/rand"
@@ -32,7 +31,6 @@ import (
 	"github.com/coreos/etcd/etcdserver/stats"
 	"github.com/coreos/etcd/pkg/fileutil"
 	"github.com/coreos/etcd/pkg/idutil"
-	"github.com/coreos/etcd/pkg/metrics"
 	"github.com/coreos/etcd/pkg/pbutil"
 	"github.com/coreos/etcd/pkg/timeutil"
 	"github.com/coreos/etcd/pkg/types"
@@ -277,7 +275,6 @@ func (s *EtcdServer) Start() {
 	s.start()
 	go s.publish(defaultPublishRetryInterval)
 	go s.purgeFile()
-	metrics.Publish("raft.status", expvar.Func(s.raftStatus))
 }
 
 // start prepares and starts server in a new goroutine. It is no longer safe to
@@ -540,8 +537,6 @@ func (s *EtcdServer) LeaderStats() []byte {
 
 func (s *EtcdServer) StoreStats() []byte { return s.store.JsonStats() }
 
-func (s *EtcdServer) raftStatus() interface{} { return s.r.Status() }
-
 func (s *EtcdServer) AddMember(ctx context.Context, memb Member) error {
 	// TODO: move Member to protobuf type
 	b, err := json.Marshal(memb)