discovery: add command line flag for discovery-proxy

discovery/discovery.go

@@ -22,7 +22,6 @@ import (
 	"log"
 	"net/http"
 	"net/url"
-	"os"
 	"path"
 	"sort"
 	"strconv"
@@ -46,16 +45,14 @@ var (
 )
 
 const (
-	// Environment variable used to configure an HTTP proxy for discovery
-	DiscoveryProxyEnv = "ETCD_DISCOVERY_PROXY"
 	// Number of retries discovery will attempt before giving up and erroring out.
 	nRetries = uint(3)
 )
 
 // JoinCluster will connect to the discovery service at the given url, and
 // register the server represented by the given id and config to the cluster
-func JoinCluster(durl string, id types.ID, config string) (string, error) {
-	d, err := newDiscovery(durl, id)
+func JoinCluster(durl, dproxyurl string, id types.ID, config string) (string, error) {
+	d, err := newDiscovery(durl, dproxyurl, id)
 	if err != nil {
 		return "", err
 	}
@@ -64,8 +61,8 @@ func JoinCluster(durl string, id types.ID, config string) (string, error) {
 
 // GetCluster will connect to the discovery service at the given url and
 // retrieve a string describing the cluster
-func GetCluster(durl string) (string, error) {
-	d, err := newDiscovery(durl, 0)
+func GetCluster(durl, dproxyurl string) (string, error) {
+	d, err := newDiscovery(durl, dproxyurl, 0)
 	if err != nil {
 		return "", err
 	}
@@ -82,11 +79,10 @@ type discovery struct {
 	clock clockwork.Clock
 }
 
-// proxyFuncFromEnv builds a proxy function if the appropriate environment
-// variable is set. It performs basic sanitization of the environment variable
-// and returns any error encountered.
-func proxyFuncFromEnv() (func(*http.Request) (*url.URL, error), error) {
-	proxy := os.Getenv(DiscoveryProxyEnv)
+// newProxyFunc builds a proxy function from the given string, which should
+// represent a URL that can be used as a proxy. It performs basic
+// sanitization of the URL and returns any error encountered.
+func newProxyFunc(proxy string) (func(*http.Request) (*url.URL, error), error) {
 	if proxy == "" {
 		return nil, nil
 	}
@@ -111,14 +107,14 @@ func proxyFuncFromEnv() (func(*http.Request) (*url.URL, error), error) {
 	return http.ProxyURL(proxyURL), nil
 }
 
-func newDiscovery(durl string, id types.ID) (*discovery, error) {
+func newDiscovery(durl, dproxyurl string, id types.ID) (*discovery, error) {
 	u, err := url.Parse(durl)
 	if err != nil {
 		return nil, err
 	}
 	token := u.Path
 	u.Path = ""
-	pf, err := proxyFuncFromEnv()
+	pf, err := newProxyFunc(dproxyurl)
 	if err != nil {
 		return nil, err
 	}

discovery/discovery_test.go

@@ -20,7 +20,6 @@ import (
 	"errors"
 	"math/rand"
 	"net/http"
-	"os"
 	"reflect"
 	"sort"
 	"strconv"
@@ -32,9 +31,8 @@ import (
 	"github.com/coreos/etcd/client"
 )
 
-func TestProxyFuncFromEnvUnset(t *testing.T) {
-	os.Setenv(DiscoveryProxyEnv, "")
-	pf, err := proxyFuncFromEnv()
+func TestNewProxyFuncUnset(t *testing.T) {
+	pf, err := newProxyFunc("")
 	if pf != nil {
 		t.Fatal("unexpected non-nil proxyFunc")
 	}
@@ -43,14 +41,13 @@ func TestProxyFuncFromEnvUnset(t *testing.T) {
 	}
 }
 
-func TestProxyFuncFromEnvBad(t *testing.T) {
+func TestNewProxyFuncBad(t *testing.T) {
 	tests := []string{
 		"%%",
 		"http://foo.com/%1",
 	}
 	for i, in := range tests {
-		os.Setenv(DiscoveryProxyEnv, in)
-		pf, err := proxyFuncFromEnv()
+		pf, err := newProxyFunc(in)
 		if pf != nil {
 			t.Errorf("#%d: unexpected non-nil proxyFunc", i)
 		}
@@ -60,14 +57,13 @@ func TestProxyFuncFromEnvBad(t *testing.T) {
 	}
 }
 
-func TestProxyFuncFromEnv(t *testing.T) {
+func TestNewProxyFunc(t *testing.T) {
 	tests := map[string]string{
 		"bar.com":              "http://bar.com",
 		"http://disco.foo.bar": "http://disco.foo.bar",
 	}
 	for in, w := range tests {
-		os.Setenv(DiscoveryProxyEnv, in)
-		pf, err := proxyFuncFromEnv()
+		pf, err := newProxyFunc(in)
 		if pf == nil {
 			t.Errorf("%s: unexpected nil proxyFunc", in)
 			continue

etcdmain/etcd.go

@@ -57,6 +57,7 @@ var (
 	name         = fs.String("name", "default", "Unique human-readable name for this node")
 	dir          = fs.String("data-dir", "", "Path to the data directory")
 	durl         = fs.String("discovery", "", "Discovery service used to bootstrap the cluster")
+	dproxy       = fs.String("discovery-proxy", "", "HTTP proxy to use for traffic to discovery service")
 	snapCount    = fs.Uint64("snapshot-count", etcdserver.DefaultSnapCount, "Number of committed transactions to trigger a snapshot")
 	printVersion = fs.Bool("version", false, "Print the version and exit")
 
@@ -259,14 +260,15 @@ func startEtcd() error {
 	}
 
 	cfg := &etcdserver.ServerConfig{
-		Name:         *name,
-		ClientURLs:   acurls,
-		DataDir:      *dir,
-		SnapCount:    *snapCount,
-		Cluster:      cls,
-		DiscoveryURL: *durl,
-		NewCluster:   clusterStateFlag.String() == clusterStateFlagNew,
-		Transport:    pt,
+		Name:           *name,
+		ClientURLs:     acurls,
+		DataDir:        *dir,
+		SnapCount:      *snapCount,
+		Cluster:        cls,
+		DiscoveryURL:   *durl,
+		DiscoveryProxy: *dproxy,
+		NewCluster:     clusterStateFlag.String() == clusterStateFlagNew,
+		Transport:      pt,
 	}
 	var s *etcdserver.EtcdServer
 	s, err = etcdserver.NewServer(cfg)
@@ -303,7 +305,7 @@ func startProxy() error {
 	}
 
 	if *durl != "" {
-		s, err := discovery.GetCluster(*durl)
+		s, err := discovery.GetCluster(*durl, *dproxy)
 		if err != nil {
 			return err
 		}

etcdserver/config.go

@@ -27,14 +27,15 @@ import (
 
 // ServerConfig holds the configuration of etcd as taken from the command line or discovery.
 type ServerConfig struct {
-	Name         string
-	DiscoveryURL string
-	ClientURLs   types.URLs
-	DataDir      string
-	SnapCount    uint64
-	Cluster      *Cluster
-	NewCluster   bool
-	Transport    *http.Transport
+	Name           string
+	DiscoveryURL   string
+	DiscoveryProxy string
+	ClientURLs     types.URLs
+	DataDir        string
+	SnapCount      uint64
+	Cluster        *Cluster
+	NewCluster     bool
+	Transport      *http.Transport
 }
 
 // VerifyBootstrapConfig sanity-checks the initial config and returns an error

etcdserver/server.go

@@ -204,7 +204,7 @@ func NewServer(cfg *ServerConfig) (*EtcdServer, error) {
 		}
 		m := cfg.Cluster.MemberByName(cfg.Name)
 		if cfg.ShouldDiscover() {
-			s, err := discovery.JoinCluster(cfg.DiscoveryURL, m.ID, cfg.Cluster.String())
+			s, err := discovery.JoinCluster(cfg.DiscoveryURL, cfg.DiscoveryProxy, m.ID, cfg.Cluster.String())
 			if err != nil {
 				return nil, err
 			}