Add aTLS endpoint to KMS (#236)

* Move file watcher and validator to internal

* Add aTLS endpoint to KMS for Kubernetes external requests

* Update Go version in Dockerfiles

* Move most KMS packages to internal

Signed-off-by: Daniel Weiße <dw@edgeless.systems>

internal/watcher/watcher_test.go

@@ -0,0 +1,172 @@
+package watcher
+
+import (
+	"errors"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/edgelesssys/constellation/internal/logger"
+	"github.com/fsnotify/fsnotify"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestWatcher(t *testing.T) {
+	someErr := errors.New("error")
+
+	testCases := map[string]struct {
+		updater      *testUpdater
+		watcher      *testWatcher
+		events       []fsnotify.Event
+		watchErr     error
+		wantAddCalls int
+		wantErr      bool
+	}{
+		"success": {
+			updater: &testUpdater{},
+			watcher: &testWatcher{
+				events: make(chan fsnotify.Event, 1),
+				errors: make(chan error, 1),
+			},
+			events: []fsnotify.Event{
+				{Op: fsnotify.Write, Name: "test"},
+				{Op: fsnotify.Chmod, Name: "test"},
+				{Op: fsnotify.Create, Name: "test"},
+				{Op: fsnotify.Rename, Name: "test"},
+			},
+			wantAddCalls: 1,
+		},
+		"failing update does not interrupt execution": {
+			updater: &testUpdater{
+				err: someErr,
+			},
+			watcher: &testWatcher{
+				events: make(chan fsnotify.Event, 1),
+				errors: make(chan error, 1),
+			},
+			events: []fsnotify.Event{
+				{Op: fsnotify.Write, Name: "test"},
+				{Op: fsnotify.Write, Name: "test"},
+			},
+			wantAddCalls: 1,
+		},
+		"removed file gets re-added": {
+			updater: &testUpdater{},
+			watcher: &testWatcher{
+				events: make(chan fsnotify.Event, 1),
+				errors: make(chan error, 1),
+			},
+			events: []fsnotify.Event{
+				{Op: fsnotify.Write, Name: "test"},
+				{Op: fsnotify.Remove, Name: "test"},
+			},
+			wantAddCalls: 2,
+		},
+		"re-adding file fails": {
+			updater: &testUpdater{},
+			watcher: &testWatcher{
+				addErr: someErr,
+				events: make(chan fsnotify.Event, 1),
+				errors: make(chan error, 1),
+			},
+			events:       []fsnotify.Event{{Op: fsnotify.Remove, Name: "test"}},
+			wantAddCalls: 1,
+			wantErr:      true,
+		},
+		"add file fails": {
+			updater: &testUpdater{},
+			watcher: &testWatcher{
+				addErr: someErr,
+				events: make(chan fsnotify.Event, 1),
+				errors: make(chan error, 1),
+			},
+			wantAddCalls: 1,
+			wantErr:      true,
+		},
+		"error during watch": {
+			updater: &testUpdater{},
+			watcher: &testWatcher{
+				events: make(chan fsnotify.Event, 1),
+				errors: make(chan error, 1),
+			},
+			wantAddCalls: 1,
+			watchErr:     someErr,
+			wantErr:      true,
+		},
+	}
+
+	for name, tc := range testCases {
+		t.Run(name, func(t *testing.T) {
+			assert := assert.New(t)
+
+			watcher := &FileWatcher{
+				log:     logger.NewTest(t),
+				updater: tc.updater,
+				watcher: tc.watcher,
+				done:    make(chan struct{}, 1),
+			}
+
+			wg := sync.WaitGroup{}
+			wg.Add(1)
+			go func() {
+				defer wg.Done()
+				err := watcher.Watch("test")
+				if tc.wantErr {
+					assert.Error(err)
+					return
+				}
+				assert.NoError(err)
+			}()
+
+			time.Sleep(15 * time.Millisecond)
+
+			for _, event := range tc.events {
+				tc.watcher.events <- event
+			}
+
+			if tc.watchErr != nil {
+				tc.watcher.errors <- tc.watchErr
+			}
+
+			close(tc.watcher.events)
+			assert.NoError(watcher.Close())
+			wg.Wait()
+
+			// check that the watchers Add method was called the expected number of times
+			assert.Equal(tc.wantAddCalls, tc.watcher.addCalled)
+		})
+	}
+}
+
+type testUpdater struct {
+	err error
+}
+
+func (u *testUpdater) Update() error {
+	return u.err
+}
+
+type testWatcher struct {
+	addCalled int
+	addErr    error
+	closeErr  error
+	events    chan fsnotify.Event
+	errors    chan error
+}
+
+func (w *testWatcher) Add(path string) error {
+	w.addCalled++
+	return w.addErr
+}
+
+func (w *testWatcher) Close() error {
+	return w.closeErr
+}
+
+func (w *testWatcher) Events() <-chan fsnotify.Event {
+	return w.events
+}
+
+func (w *testWatcher) Errors() <-chan error {
+	return w.errors
+}