package proxy import ( "fmt" "io/ioutil" "log" "os" "os/exec" "os/signal" "strconv" "syscall" "testing" "time" ) // testLogger is a logger that can be used by tests that require a // *log.Logger instance. var testLogger = log.New(os.Stderr, "logger: ", log.LstdFlags) // testTempDir returns a temporary directory and a cleanup function. func testTempDir(t *testing.T) (string, func()) { t.Helper() td, err := ioutil.TempDir("", "test-agent-proxy") if err != nil { t.Fatalf("err: %s", err) } return td, func() { if err := os.RemoveAll(td); err != nil { t.Fatalf("err: %s", err) } } } // helperProcessSentinel is a sentinel value that is put as the first // argument following "--" and is used to determine if TestHelperProcess // should run. const helperProcessSentinel = "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 { cs := []string{"-test.run=TestHelperProcess", "--", helperProcessSentinel} cs = append(cs, s...) cmd := exec.Command(os.Args[0], cs...) cmd.Stdout = os.Stdout cmd.Stderr = os.Stderr return cmd } // 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 { // While running, this creates a file in the given directory (args[0]) // and deletes it only when it is stopped. case "start-stop": ch := make(chan os.Signal, 1) signal.Notify(ch, os.Interrupt, syscall.SIGTERM) defer signal.Stop(ch) path := args[0] var data []byte data = append(data, []byte(os.Getenv(EnvProxyID))...) data = append(data, ':') data = append(data, []byte(os.Getenv(EnvProxyToken))...) if err := ioutil.WriteFile(path, data, 0644); err != nil { t.Fatalf("err: %s", err) } defer os.Remove(path) <-ch // Restart writes to a file and keeps running while that file still // exists. When that file is removed, this process exits. This can be // used to test restarting. case "restart": ch := make(chan os.Signal, 1) signal.Notify(ch, os.Interrupt) defer signal.Stop(ch) // Write the file path := args[0] if err := ioutil.WriteFile(path, []byte("hello"), 0644); err != nil { fmt.Fprintf(os.Stderr, "Error: %s\n", err) os.Exit(1) } // While the file still exists, do nothing. When the file no longer // exists, we exit. for { time.Sleep(25 * time.Millisecond) if _, err := os.Stat(path); os.IsNotExist(err) { break } select { case <-ch: // We received an interrupt, clean exit os.Remove(path) break default: } } case "stop-kill": // Setup listeners so it is ignored ch := make(chan os.Signal, 1) signal.Notify(ch, os.Interrupt) defer signal.Stop(ch) path := args[0] data := []byte(os.Getenv(EnvProxyToken)) for { if err := ioutil.WriteFile(path, data, 0644); err != nil { t.Fatalf("err: %s", err) } time.Sleep(25 * time.Millisecond) } case "output": fmt.Fprintf(os.Stdout, "hello stdout\n") fmt.Fprintf(os.Stderr, "hello stderr\n") // Sync to be sure it is written out of buffers os.Stdout.Sync() os.Stderr.Sync() // Output a file to signal we've written to stdout/err path := args[0] if err := ioutil.WriteFile(path, []byte("hello"), 0644); err != nil { fmt.Fprintf(os.Stderr, "Error: %s\n", err) os.Exit(1) } <-make(chan struct{}) // Parent runs the given process in a Daemon and then sleeps until the test // code kills it. It exists to test that the Daemon-managed child process // survives it's parent exiting which we can't test directly without exiting // the test process so we need an extra level of indirection. The test code // using this must pass a file path as the first argument for the child // processes PID to be written and then must take care to clean up that PID // later or the child will be left running forever. // // If the PID file already exists, it will "adopt" the child rather than // launch a new one. case "parent": // We will write the PID for the child to the file in the first argument // then pass rest of args through to command. pidFile := args[0] d := &Daemon{ Command: helperProcess(args[1:]...), Logger: testLogger, PidPath: pidFile, } _, err := os.Stat(pidFile) if err == nil { // pidFile exists, read it and "adopt" the process bs, err := ioutil.ReadFile(pidFile) if err != nil { log.Printf("Error: %s", err) os.Exit(1) } pid, err := strconv.Atoi(string(bs)) if err != nil { log.Printf("Error: %s", err) os.Exit(1) } // Make a fake snapshot to load snapshot := map[string]interface{}{ "Pid": pid, "CommandPath": d.Command.Path, "CommandArgs": d.Command.Args, "CommandDir": d.Command.Dir, "CommandEnv": d.Command.Env, "ProxyToken": "", } d.UnmarshalSnapshot(snapshot) } if err := d.Start(); err != nil { log.Printf("Error: %s", err) os.Exit(1) } log.Println("Started child") // Wait "forever" (calling test chooses when we exit with signal/Wait to // minimise coordination). for { time.Sleep(time.Hour) } default: fmt.Fprintf(os.Stderr, "Unknown command: %q\n", cmd) os.Exit(2) } }