fix(systemd): unmask runtime units when mask=False

system/systemd_test.go

@@ -25,10 +25,10 @@ Address=10.209.171.177/19
 	}
 	defer os.RemoveAll(dir)
 
-	dst := UnitDestination(&u, dir)
+	dst := u.Destination(dir)
 	expectDst := path.Join(dir, "run", "systemd", "network", "50-eth0.network")
 	if dst != expectDst {
-		t.Fatalf("UnitDestination returned %s, expected %s", dst, expectDst)
+		t.Fatalf("unit.Destination returned %s, expected %s", dst, expectDst)
 	}
 
 	if err := PlaceUnit(&u, dst); err != nil {
@@ -69,18 +69,18 @@ func TestUnitDestination(t *testing.T) {
 		DropIn: false,
 	}
 
-	dst := UnitDestination(&u, dir)
+	dst := u.Destination(dir)
 	expectDst := path.Join(dir, "etc", "systemd", "system", "foobar.service")
 	if dst != expectDst {
-		t.Errorf("UnitDestination returned %s, expected %s", dst, expectDst)
+		t.Errorf("unit.Destination returned %s, expected %s", dst, expectDst)
 	}
 
 	u.DropIn = true
 
-	dst = UnitDestination(&u, dir)
+	dst = u.Destination(dir)
 	expectDst = path.Join(dir, "etc", "systemd", "system", "foobar.service.d", cloudConfigDropIn)
 	if dst != expectDst {
-		t.Errorf("UnitDestination returned %s, expected %s", dst, expectDst)
+		t.Errorf("unit.Destination returned %s, expected %s", dst, expectDst)
 	}
 }
 
@@ -100,10 +100,10 @@ Where=/media/state
 	}
 	defer os.RemoveAll(dir)
 
-	dst := UnitDestination(&u, dir)
+	dst := u.Destination(dir)
 	expectDst := path.Join(dir, "etc", "systemd", "system", "media-state.mount")
 	if dst != expectDst {
-		t.Fatalf("UnitDestination returned %s, expected %s", dst, expectDst)
+		t.Fatalf("unit.Destination returned %s, expected %s", dst, expectDst)
 	}
 
 	if err := PlaceUnit(&u, dst); err != nil {
@@ -156,7 +156,8 @@ func TestMaskUnit(t *testing.T) {
 	defer os.RemoveAll(dir)
 
 	// Ensure mask works with units that do not currently exist
-	if err := MaskUnit("foo.service", dir); err != nil {
+	uf := &Unit{Name: "foo.service"}
+	if err := MaskUnit(uf, dir); err != nil {
 		t.Fatalf("Unable to mask new unit: %v", err)
 	}
 	fooPath := path.Join(dir, "etc", "systemd", "system", "foo.service")
@@ -169,11 +170,12 @@ func TestMaskUnit(t *testing.T) {
 	}
 
 	// Ensure mask works with unit files that already exist
+	ub := &Unit{Name: "bar.service"}
 	barPath := path.Join(dir, "etc", "systemd", "system", "bar.service")
 	if _, err := os.Create(barPath); err != nil {
 		t.Fatalf("Error creating new unit file: %v", err)
 	}
-	if err := MaskUnit("bar.service", dir); err != nil {
+	if err := MaskUnit(ub, dir); err != nil {
 		t.Fatalf("Unable to mask existing unit: %v", err)
 	}
 	barTgt, err := os.Readlink(barPath)
@@ -184,3 +186,94 @@ func TestMaskUnit(t *testing.T) {
 		t.Fatalf("unit not masked, got unit target", barTgt)
 	}
 }
+
+func TestUnmaskUnit(t *testing.T) {
+	dir, err := ioutil.TempDir(os.TempDir(), "coreos-cloudinit-")
+	if err != nil {
+		t.Fatalf("Unable to create tempdir: %v", err)
+	}
+	defer os.RemoveAll(dir)
+
+	nilUnit := &Unit{Name: "null.service"}
+	if err := UnmaskUnit(nilUnit, dir); err != nil {
+		t.Errorf("unexpected error from unmasking nonexistent unit: %v", err)
+	}
+
+	uf := &Unit{Name: "foo.service", Content: "[Service]\nExecStart=/bin/true"}
+	dst := uf.Destination(dir)
+	if err := os.MkdirAll(path.Dir(dst), os.FileMode(0755)); err != nil {
+		t.Fatalf("Unable to create unit directory: %v", err)
+	}
+	if _, err := os.Create(dst); err != nil {
+		t.Fatalf("Unable to write unit file: %v", err)
+	}
+
+	if err := ioutil.WriteFile(dst, []byte(uf.Content), 700); err != nil {
+		t.Fatalf("Unable to write unit file: %v", err)
+	}
+	if err := UnmaskUnit(uf, dir); err != nil {
+		t.Errorf("unmask of non-empty unit returned unexpected error: %v", err)
+	}
+	got, _ := ioutil.ReadFile(dst)
+	if string(got) != uf.Content {
+		t.Errorf("unmask of non-empty unit mutated unit contents unexpectedly")
+	}
+
+	ub := &Unit{Name: "bar.service"}
+	dst = ub.Destination(dir)
+	if err := os.Symlink("/dev/null", dst); err != nil {
+		t.Fatalf("Unable to create masked unit: %v", err)
+	}
+	if err := UnmaskUnit(ub, dir); err != nil {
+		t.Errorf("unmask of unit returned unexpected error: %v", err)
+	}
+	if _, err := os.Stat(dst); !os.IsNotExist(err) {
+		t.Errorf("expected %s to not exist after unmask, but got err: %s", err)
+	}
+}
+
+func TestNullOrEmpty(t *testing.T) {
+	dir, err := ioutil.TempDir(os.TempDir(), "coreos-cloudinit-")
+	if err != nil {
+		t.Fatalf("Unable to create tempdir: %v", err)
+	}
+	defer os.RemoveAll(dir)
+
+	non := path.Join(dir, "does_not_exist")
+	ne, err := nullOrEmpty(non)
+	if !os.IsNotExist(err) {
+		t.Errorf("nullOrEmpty on nonexistent file returned bad error: %v", err)
+	}
+	if ne {
+		t.Errorf("nullOrEmpty returned true unxpectedly")
+	}
+
+	regEmpty := path.Join(dir, "regular_empty_file")
+	_, err = os.Create(regEmpty)
+	if err != nil {
+		t.Fatalf("Unable to create tempfile: %v", err)
+	}
+	gotNe, gotErr := nullOrEmpty(regEmpty)
+	if !gotNe || gotErr != nil {
+		t.Errorf("nullOrEmpty of regular empty file returned %t, %v - want true, nil", gotNe, gotErr)
+	}
+
+	reg := path.Join(dir, "regular_file")
+	if err := ioutil.WriteFile(reg, []byte("asdf"), 700); err != nil {
+		t.Fatalf("Unable to create tempfile: %v", err)
+	}
+	gotNe, gotErr = nullOrEmpty(reg)
+	if gotNe || gotErr != nil {
+		t.Errorf("nullOrEmpty of regular file returned %t, %v - want false, nil", gotNe, gotErr)
+	}
+
+	null := path.Join(dir, "null")
+	if err := os.Symlink(os.DevNull, null); err != nil {
+		t.Fatalf("Unable to create /dev/null link: %s", err)
+	}
+	gotNe, gotErr = nullOrEmpty(null)
+	if !gotNe || gotErr != nil {
+		t.Errorf("nullOrEmpty of null symlink returned %t, %v - want true, nil", gotNe, gotErr)
+	}
+
+}