mounts: test the clearing loop, the look's own clearing and a disk's presence; clear only a taken-over unit's earlier failure; clear and re-arm an automount that gave up; refuse a transient unit of the same name (review of #162)

modules/mounts/cmd/mounts/write_test.go

@@ -7,6 +7,7 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+	"sync"
 	"testing"
 	"time"
 )
@@ -16,6 +17,8 @@ const testPassword = "s3cr3t-Pa55"
 
 // fakeSystem is a machine under a temporary root with a recorded service manager.
 type fakeSystem struct {
+	// mu guards calls, units and reachable, for a test that runs RunApply beside itself.
+	mu    sync.Mutex
 	t     *testing.T
 	root  string
 	calls []string
@@ -55,6 +58,8 @@ func (f *fakeSystem) read(p string) string {
 }
 
 func (f *fakeSystem) run(_ context.Context, name string, args ...string) (string, error) {
+	f.mu.Lock()
+	defer f.mu.Unlock()
 	f.calls = append(f.calls, name+" "+strings.Join(args, " "))
 	if name != "systemctl" || len(args) == 0 {
 		return "", nil
@@ -77,6 +82,12 @@ func (f *fakeSystem) run(_ context.Context, name string, args ...string) (string
 	case "enable":
 		u := args[len(args)-1]
 		f.units[u] = map[string]string{"ActiveState": "active", "UnitFileState": "enabled"}
+	case "start":
+		u := args[len(args)-1]
+		if f.units[u] == nil {
+			f.units[u] = map[string]string{}
+		}
+		f.units[u]["ActiveState"], f.units[u]["Result"] = "active", "success"
 	case "reset-failed":
 		u := args[len(args)-1]
 		if f.units[u]["ActiveState"] == "failed" {
@@ -93,6 +104,8 @@ func (f *fakeSystem) machine() *Machine {
 func (f *fakeSystem) applier(now time.Time) *Applier {
 	return &Applier{M: f.machine(), Act: true, Judge: true,
 		Dial: func(addr string, _ time.Duration) error {
+			f.mu.Lock()
+			defer f.mu.Unlock()
 			if f.reachable[addr] {
 				return nil
 			}
@@ -104,6 +117,8 @@ func (f *fakeSystem) applier(now time.Time) *Applier {
 }
 
 func (f *fakeSystem) called(prefix string) bool {
+	f.mu.Lock()
+	defer f.mu.Unlock()
 	for _, c := range f.calls {
 		if strings.HasPrefix(c, prefix) {
 			return true
@@ -565,3 +580,10 @@ func TestApplyActsAndWatchJudgesAndNeitherDoesTheOthersWork(t *testing.T) {
 		t.Error("the password leaked")
 	}
 }
+
+// setUnit sets one unit's state as the service manager answers it, under the lock.
+func (f *fakeSystem) setUnit(unit string, state map[string]string) {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	f.units[unit] = state
+}