consul/command/connect/envoy/exec_test.go

174 lines
3.8 KiB
Go

// +build linux darwin
package envoy
import (
"encoding/json"
"fmt"
"io/ioutil"
"os"
"os/exec"
"testing"
"time"
"github.com/stretchr/testify/require"
)
func TestExecEnvoy(t *testing.T) {
require := require.New(t)
cmd, destroy := helperProcess("exec-fake-envoy")
defer destroy()
cmd.Stderr = os.Stderr
outBytes, err := cmd.Output()
if err != nil {
t.Fatalf("error launching child process: %v", err)
}
var got FakeEnvoyExecData
require.NoError(json.Unmarshal(outBytes, &got))
expectArgs := []string{
"--v2-config-only",
"--disable-hot-restart",
"--config-path",
"/dev/fd/3",
"--fake-envoy-arg",
}
expectConfigPath := "/dev/fd/3"
expectConfigData := fakeEnvoyTestData
require.Equal(expectArgs, got.Args)
require.Equal(expectConfigPath, got.ConfigPath)
require.Equal(expectConfigData, got.ConfigData)
}
type FakeEnvoyExecData struct {
Args []string `json:"args"`
ConfigPath string `json:"configPath"`
ConfigData string `json:"configData"`
}
// helperProcessSentinel is a sentinel value that is put as the first
// argument following "--" and is used to determine if TestHelperProcess
// should run.
const helperProcessSentinel = "GO_WANT_HELPER_PROCESS"
// helperProcess returns an *exec.Cmd that can be used to execute the
// TestHelperProcess function below. This can be used to test multi-process
// interactions.
func helperProcess(s ...string) (*exec.Cmd, func()) {
cs := []string{"-test.run=TestHelperProcess", "--", helperProcessSentinel}
cs = append(cs, s...)
cmd := exec.Command(os.Args[0], cs...)
destroy := func() {
if p := cmd.Process; p != nil {
p.Kill()
}
}
return cmd, destroy
}
const fakeEnvoyTestData = "pahx9eiPoogheb4haeb2abeem1QuireWahtah1Udi5ae4fuD0c"
// This is not a real test. This is just a helper process kicked off by tests
// using the helperProcess helper function.
func TestHelperProcess(t *testing.T) {
args := os.Args
for len(args) > 0 {
if args[0] == "--" {
args = args[1:]
break
}
args = args[1:]
}
if len(args) == 0 || args[0] != helperProcessSentinel {
return
}
defer os.Exit(0)
args = args[1:] // strip sentinel value
cmd, args := args[0], args[1:]
switch cmd {
case "exec-fake-envoy":
// this will just exec the "fake-envoy" flavor below
limitProcessLifetime(2 * time.Minute)
err := execEnvoy(
os.Args[0],
[]string{
"-test.run=TestHelperProcess",
"--",
helperProcessSentinel,
"fake-envoy",
},
[]string{"--fake-envoy-arg"},
[]byte(fakeEnvoyTestData),
)
if err != nil {
fmt.Fprintf(os.Stderr, "fake envoy process failed to exec: %v\n", err)
os.Exit(1)
}
case "fake-envoy":
// This subcommand is instrumented to verify some settings
// survived an exec.
limitProcessLifetime(2 * time.Minute)
data := FakeEnvoyExecData{
Args: args,
}
// Dump all of the args.
var captureNext bool
for _, arg := range args {
if arg == "--config-path" {
captureNext = true
} else if captureNext {
data.ConfigPath = arg
captureNext = false
}
}
if data.ConfigPath == "" {
fmt.Fprintf(os.Stderr, "did not detect a --config-path argument passed through\n")
os.Exit(1)
}
d, err := ioutil.ReadFile(data.ConfigPath)
if err != nil {
fmt.Fprintf(os.Stderr, "could not read provided --config-path file %q: %v\n", data.ConfigPath, err)
os.Exit(1)
}
data.ConfigData = string(d)
enc := json.NewEncoder(os.Stdout)
if err := enc.Encode(&data); err != nil {
fmt.Fprintf(os.Stderr, "could not dump results to stdout: %v", err)
os.Exit(1)
}
default:
fmt.Fprintf(os.Stderr, "Unknown command: %q\n", cmd)
os.Exit(2)
}
}
// limitProcessLifetime installs a background goroutine that self-exits after
// the specified duration elapses to prevent leaking processes from tests that
// may spawn them.
func limitProcessLifetime(dur time.Duration) {
go time.AfterFunc(dur, func() {
os.Exit(99)
})
}