Validate quote balance in installFlags (#556)

* Validate balanced quotes in installFlags

Signed-off-by: Kimmo Lehto <klehto@mirantis.com>

pkg/apis/k0sctl.k0sproject.io/v1beta1/cluster/host.go

@@ -77,6 +77,33 @@ func (h *Host) SetDefaults() {
 	}
 }
 
+func validateBalancedQuotes(val any) error {
+	s, ok := val.(string)
+	if !ok {
+		return fmt.Errorf("invalid type")
+	}
+
+	quoteCount := make(map[rune]int)
+
+	for i, ch := range s {
+		if i > 0 && s[i-1] == '\\' {
+			continue
+		}
+
+		if ch == '\'' || ch == '"' {
+			quoteCount[ch]++
+		}
+	}
+
+	for _, count := range quoteCount {
+		if count%2 != 0 {
+			return fmt.Errorf("unbalanced quotes in %s", s)
+		}
+	}
+
+	return nil
+}
+
 func (h *Host) Validate() error {
 	// For rig validation
 	v := validator.New()
@@ -89,6 +116,7 @@ func (h *Host) Validate() error {
 		validation.Field(&h.PrivateAddress, is.IP),
 		validation.Field(&h.Files),
 		validation.Field(&h.NoTaints, validation.When(h.Role != "controller+worker", validation.NotIn(true).Error("noTaints can only be true for controller+worker role"))),
+		validation.Field(&h.InstallFlags, validation.Each(validation.By(validateBalancedQuotes))),
 	)
 }
 

pkg/apis/k0sctl.k0sproject.io/v1beta1/cluster/host_test.go

@@ -119,3 +119,22 @@ func TestK0sInstallCommand(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, `k0s install worker --enable-cloud-provider --data-dir=/tmp/k0s --token-file "from-configurer"`, cmd)
 }
+
+func TestValidation(t *testing.T) {
+	t.Run("installFlags", func(t *testing.T) {
+		h := Host{
+			Role:         "worker",
+			InstallFlags: []string{"--foo"},
+		}
+		require.NoError(t, h.Validate())
+
+		h.InstallFlags = []string{`--foo=""`, `--bar=''`}
+		require.NoError(t, h.Validate())
+
+		h.InstallFlags = []string{`--foo="`, "--bar"}
+		require.ErrorContains(t, h.Validate(), "unbalanced quotes")
+
+		h.InstallFlags = []string{"--bar='"}
+		require.ErrorContains(t, h.Validate(), "unbalanced quotes")
+	})
+}