make supported interfaces configurable

agent/cmd/cmd.go

@@ -39,14 +39,15 @@ import (
 
 // Flags defines agent CLI flags.
 type Flags struct {
- PeerIP string
- PeerPort int
- AgentServerPort int
- AgentRegistryPort int
- ConfigFile string
- Zone string
- KrakenCluster string
- SecretsFile string
+ PeerIP string
+ PeerPort int
+ AgentServerPort int
+ AgentRegistryPort int
+ ConfigFile string
+ Zone string
+ KrakenCluster string
+ SecretsFile string
+ SupportedInterfaces string
 }
 
 // ParseFlags parses agent CLI flags.
@@ -68,6 +69,9 @@ func ParseFlags() *Flags {
  &flags.KrakenCluster, "cluster", "", "cluster name (e.g. prod01-zone1)")
  flag.StringVar(
  &flags.SecretsFile, "secrets", "", "path to a secrets YAML file to load into configuration")
+ flag.StringVar(
+ &flags.SupportedInterfaces, "supported-interfaces", "eth0,ib0",
+ "an ordered csv list of ip interfaces from which host ip is determined (e.g. eth0,ib0)")
  flag.Parse()
  return &flags
 }
@@ -148,7 +152,11 @@ func Run(flags *Flags, opts ...Option) {
  go metrics.EmitVersion(stats)
 
  if flags.PeerIP == "" {
- localIP, err := netutil.GetLocalIP()
+ supportedInterfaces, err := configutil.ReadAsCSV(flags.SupportedInterfaces)
+ if err != nil {
+ log.Fatalf("Error parsing supported interfaces: %s", err)
+ }
+ localIP, err := netutil.GetLocalIP(supportedInterfaces)
  if err != nil {
  log.Fatalf("Error getting local ip: %s", err)
  }

origin/cmd/cmd.go

@@ -50,14 +50,15 @@ import (
 
 // Flags defines origin CLI flags.
 type Flags struct {
- PeerIP string
- PeerPort int
- BlobServerHostName string
- BlobServerPort int
- ConfigFile string
- Zone string
- KrakenCluster string
- SecretsFile string
+ PeerIP string
+ PeerPort int
+ BlobServerHostName string
+ BlobServerPort int
+ ConfigFile string
+ Zone string
+ KrakenCluster string
+ SecretsFile string
+ SupportedInterfaces string
 }
 
 // ParseFlags parses origin CLI flags.
@@ -79,6 +80,9 @@ func ParseFlags() *Flags {
  &flags.KrakenCluster, "cluster", "", "cluster name (e.g. prod01-zone1)")
  flag.StringVar(
  &flags.SecretsFile, "secrets", "", "path to a secrets YAML file to load into configuration")
+ flag.StringVar(
+ &flags.SupportedInterfaces, "supported-interfaces", "eth0,ib0",
+ "an ordered csv list of ip interfaces from which host ip is determined (e.g. eth0,ib0)")
  flag.Parse()
  return &flags
 }
@@ -168,7 +172,11 @@ func Run(flags *Flags, opts ...Option) {
  log.Infof("Configuring origin with hostname '%s'", hostname)
 
  if flags.PeerIP == "" {
- localIP, err := netutil.GetLocalIP()
+ supportedInterfaces, err := configutil.ReadAsCSV(flags.SupportedInterfaces)
+ if err != nil {
+ log.Fatalf("Error parsing supported interfaces: %s", err)
+ }
+ localIP, err := netutil.GetLocalIP(supportedInterfaces)
  if err != nil {
  log.Fatalf("Error getting local ip: %s", err)
  }
@@ -246,7 +254,11 @@ func Run(flags *Flags, opts ...Option) {
  if !hashRing.Contains(addr) {
  // When DNS is used for hash ring membership, the members will be IP
  // addresses instead of hostnames.
- ip, err := netutil.GetLocalIP()
+ supportedInterfaces, err := configutil.ReadAsCSV(flags.SupportedInterfaces)
+ if err != nil {
+ log.Fatalf("Error parsing supported interfaces: %s", err)
+ }
+ ip, err := netutil.GetLocalIP(supportedInterfaces)
  if err != nil {
  log.Fatalf("Error getting local ip: %s", err)
  }

utils/configutil/config.go

@@ -55,11 +55,13 @@ package configutil
 
 import (
  "bytes"
+ "encoding/csv"
  "errors"
  "fmt"
  "io/ioutil"
  "path"
  "path/filepath"
+ "strings"
 
  "github.com/uber/kraken/utils/stringset"
 
@@ -178,3 +180,13 @@ func loadFiles(config interface{}, fnames []string) error {
  }
  return nil
 }
+
+// ReadAsCSV reads a csv string and return the string slice.
+func ReadAsCSV(val string) ([]string, error) {
+ if val == "" {
+ return []string{}, nil
+ }
+ stringReader := strings.NewReader(val)
+ csvReader := csv.NewReader(stringReader)
+ return csvReader.Read()
+}

utils/netutil/netutil.go

@@ -20,10 +20,6 @@ import (
  "time"
 )
 
-// _supportedInterfaces is an ordered list of ip interfaces from which
-// host ip is determined.
-var _supportedInterfaces = []string{"eth0", "ib0"}
-
 func min(a, b time.Duration) time.Duration {
  if a < b {
  return a
@@ -65,7 +61,7 @@ func GetIP(host string) (net.IP, error) {
 }
 
 // GetLocalIP returns the ip address of the local machine.
-func GetLocalIP() (string, error) {
+func GetLocalIP(supportedInterfaces []string) (string, error) {
  ifaces, err := net.Interfaces()
  if err != nil {
  return "", fmt.Errorf("interfaces: %s", err)
@@ -95,7 +91,7 @@ func GetLocalIP() (string, error) {
  break
  }
  }
- for _, i := range _supportedInterfaces {
+ for _, i := range supportedInterfaces {
  if ip, ok := ips[i]; ok {
  return ip, nil
  }