chore!(amneziawg): refactor to be separate from wireguard

- amneziawg is now a VPN protocol and no longer a Wireguard implementation
- Use it with VPN_TYPE=amneziawg
- document AMNEZIAWG_* options in Dockerfile
- document amneziawg support in readme
- separate amneziawg settings and code from wireguard
- re-use code from wireguard whenever possible

internal/cleanup/cleanup_test.go

@@ -0,0 +1,57 @@
+package cleanup
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/golang/mock/gomock"
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_Cleanups(t *testing.T) {
+	t.Parallel()
+
+	ctrl := gomock.NewController(t)
+
+	var ACloseCalled, BCloseCalled, CCloseCalled bool
+	var (
+		AErr error
+		BErr = errors.New("B failed")
+		CErr = errors.New("C failed")
+	)
+
+	var cleanups Cleanups
+	cleanups.Add("cleaning up A", 5, func() error {
+		ACloseCalled = true
+		return AErr
+	})
+
+	cleanups.Add("cleaning up B", 3, func() error {
+		BCloseCalled = true
+		return BErr
+	})
+
+	cleanups.Add("cleaning up C", 2, func() error {
+		CCloseCalled = true
+		return CErr
+	})
+
+	logger := NewMockLogger(ctrl)
+	prevCall := logger.EXPECT().Debug("cleaning up C...")
+	prevCall = logger.EXPECT().Error("failed cleaning up C: C failed").After(prevCall)
+	prevCall = logger.EXPECT().Debug("cleaning up B...").After(prevCall)
+	prevCall = logger.EXPECT().Error("failed cleaning up B: B failed").After(prevCall)
+	logger.EXPECT().Debug("cleaning up A...").After(prevCall)
+
+	cleanups.Cleanup(logger)
+
+	cleanups.Cleanup(logger) // run twice should not close already closed
+
+	for _, cleanup := range cleanups {
+		assert.True(t, cleanup.done)
+	}
+
+	assert.True(t, ACloseCalled)
+	assert.True(t, BCloseCalled)
+	assert.True(t, CCloseCalled)
+}