etcd-agent: support rootless operation and configurable gofail ports

tools/functional-tester/etcd-agent/agent.go

@@ -39,36 +39,44 @@ type Agent struct {
 
 	cmd     *exec.Cmd
 	logfile *os.File
-	logDir  string
+
+	cfg AgentConfig
 }
 
-func newAgent(etcd, logDir string) (*Agent, error) {
+type AgentConfig struct {
+	EtcdPath      string
+	LogDir        string
+	FailpointAddr string
+	UseRoot       bool
+}
+
+func newAgent(cfg AgentConfig) (*Agent, error) {
 	// check if the file exists
-	_, err := os.Stat(etcd)
+	_, err := os.Stat(cfg.EtcdPath)
 	if err != nil {
 		return nil, err
 	}
 
-	c := exec.Command(etcd)
+	c := exec.Command(cfg.EtcdPath)
 
-	err = fileutil.TouchDirAll(logDir)
+	err = fileutil.TouchDirAll(cfg.LogDir)
 	if err != nil {
 		return nil, err
 	}
 
 	var f *os.File
-	f, err = os.Create(filepath.Join(logDir, "etcd.log"))
+	f, err = os.Create(filepath.Join(cfg.LogDir, "etcd.log"))
 	if err != nil {
 		return nil, err
 	}
 
-	return &Agent{state: stateUninitialized, cmd: c, logfile: f, logDir: logDir}, nil
+	return &Agent{state: stateUninitialized, cmd: c, logfile: f, cfg: cfg}, nil
 }
 
 // start starts a new etcd process with the given args.
 func (a *Agent) start(args ...string) error {
 	a.cmd = exec.Command(a.cmd.Path, args...)
-	a.cmd.Env = []string{"GOFAIL_HTTP=:2381"}
+	a.cmd.Env = []string{"GOFAIL_HTTP=" + a.cfg.FailpointAddr}
 	a.cmd.Stdout = a.logfile
 	a.cmd.Stderr = a.logfile
 	err := a.cmd.Start()
@@ -131,15 +139,15 @@ func (a *Agent) cleanup() error {
 	a.state = stateUninitialized
 
 	a.logfile.Close()
-	if err := archiveLogAndDataDir(a.logDir, a.dataDir()); err != nil {
+	if err := archiveLogAndDataDir(a.cfg.LogDir, a.dataDir()); err != nil {
 		return err
 	}
 
-	if err := fileutil.TouchDirAll(a.logDir); err != nil {
+	if err := fileutil.TouchDirAll(a.cfg.LogDir); err != nil {
 		return err
 	}
 
-	f, err := os.Create(filepath.Join(a.logDir, "etcd.log"))
+	f, err := os.Create(filepath.Join(a.cfg.LogDir, "etcd.log"))
 	if err != nil {
 		return err
 	}
@@ -170,14 +178,23 @@ func (a *Agent) terminate() error {
 }
 
 func (a *Agent) dropPort(port int) error {
+	if !a.cfg.UseRoot {
+		return nil
+	}
 	return netutil.DropPort(port)
 }
 
 func (a *Agent) recoverPort(port int) error {
+	if !a.cfg.UseRoot {
+		return nil
+	}
 	return netutil.RecoverPort(port)
 }
 
 func (a *Agent) setLatency(ms, rv int) error {
+	if !a.cfg.UseRoot {
+		return nil
+	}
 	if ms == 0 {
 		return netutil.RemoveLatency()
 	}

tools/functional-tester/etcd-agent/agent_test.go

@@ -79,7 +79,7 @@ func TestAgentTerminate(t *testing.T) {
 
 // newTestAgent creates a test agent and with a temp data directory.
 func newTestAgent(t *testing.T) (*Agent, string) {
-	a, err := newAgent(etcdPath, "etcd.log")
+	a, err := newAgent(AgentConfig{EtcdPath: etcdPath, LogDir: "etcd.log"})
 	if err != nil {
 		t.Fatal(err)
 	}

tools/functional-tester/etcd-agent/main.go

@@ -16,6 +16,7 @@ package main
 
 import (
 	"flag"
+	"fmt"
 	"os"
 	"path/filepath"
 
@@ -28,9 +29,26 @@ func main() {
 	etcdPath := flag.String("etcd-path", filepath.Join(os.Getenv("GOPATH"), "bin/etcd"), "the path to etcd binary")
 	etcdLogDir := flag.String("etcd-log-dir", "etcd-log", "directory to store etcd logs")
 	port := flag.String("port", ":9027", "port to serve agent server")
+	useRoot := flag.Bool("use-root", true, "use root permissions")
+	failpointAddr := flag.String("failpoint-addr", ":2381", "interface for gofail's HTTP server")
 	flag.Parse()
 
-	a, err := newAgent(*etcdPath, *etcdLogDir)
+	cfg := AgentConfig{
+		EtcdPath:      *etcdPath,
+		LogDir:        *etcdLogDir,
+		FailpointAddr: *failpointAddr,
+		UseRoot:       *useRoot,
+	}
+
+	if *useRoot && os.Getuid() != 0 {
+		fmt.Println("got --use-root=true but not root user")
+		os.Exit(1)
+	}
+	if *useRoot == false {
+		fmt.Println("root permissions disabled, agent will not modify network")
+	}
+
+	a, err := newAgent(cfg)
 	if err != nil {
 		plog.Fatal(err)
 	}

tools/functional-tester/etcd-agent/rpc_test.go

@@ -25,7 +25,7 @@ import (
 )
 
 func init() {
-	defaultAgent, err := newAgent(etcdPath, "etcd.log")
+	defaultAgent, err := newAgent(AgentConfig{EtcdPath: etcdPath, LogDir: "etcd.log"})
 	if err != nil {
 		log.Panic(err)
 	}