fix: add tag validation to MatchTags (#410)

this fixes a small oversight in #343 and actually validates the individual tags against what is accepted by the API

https://github.com/proxmox/pve-common/blob/master/src/PVE/JSONSchema.pm#L706

```
our $PVE_TAG_RE = qr/[a-z0-9_][a-z0-9_\-\+\.]*/i;
```

api/v1alpha1/proxmoxmachine_types.go

@@ -229,6 +229,8 @@ type TemplateSelector struct {
 	// Passed tags must be an exact 1:1 match with the tags on the template you want to use.
 	// If multiple VM templates with the same set of tags are found, provisioning will fail.
 	//
+	// +listType=set
+	// +kubebuilder:validation:items:Pattern=`^(?i)[a-z0-9_][a-z0-9_\-\+\.]*$`
 	// +kubebuilder:validation:MinItems=1
 	MatchTags []string `json:"matchTags"`
 }

api/v1alpha1/proxmoxmachine_types_test.go

@@ -18,6 +18,7 @@ package v1alpha1
 
 import (
 	"context"
+	"strconv"
 
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
@@ -86,6 +87,57 @@ var _ = Describe("ProxmoxMachine Test", func() {
 
 			Expect(k8sClient.Create(context.Background(), dm)).Should(MatchError(ContainSubstring("should have at least 1 items")))
 		})
+
+		It("Should only allow valid MatchTags", func() {
+			testCases := []struct {
+				tag          string
+				expectErrror bool
+				errorMessage string
+			}{
+				// Valid Tags
+				{"valid_tag", false, ""},
+				{"Valid-Tag", false, ""},
+				{"valid.tag", false, ""},
+				{"VALID+TAG", false, ""},
+				{"123tag", false, ""},
+				{"tag123", false, ""},
+				{"tag_with-hyphen", false, ""},
+				{"tag.with.plus+_and-hyphen", false, ""},
+				{"_tag_with_underscore", false, ""},
+
+				// Invalid Tags
+				{"", true, "in body should match"},         // Empty string
+				{"-invalid", true, "in body should match"}, // Starts with a hyphen
+				{"+invalid", true, "in body should match"}, // Starts with a plus
+				{".invalid", true, "in body should match"}, // Starts with a dot
+				{" invalid", true, "in body should match"}, // Starts with a space
+				{"invalid!", true, "in body should match"}, // Contains an exclamation mark
+				{"invalid@", true, "in body should match"}, // Contains an at symbol
+				{"invalid#", true, "in body should match"}, // Contains a hash symbol
+				{"inval id", true, "in body should match"}, // Contains a whitespace
+			}
+
+			// Iterate through each test case
+			for i, testCase := range testCases {
+				// Create a new ProxmoxMachine object for each test case
+				dm := defaultMachine()
+
+				// Set the name of the machine to a unique value based on the test case index
+				dm.ObjectMeta.Name = "test-machine-" + strconv.Itoa(i)
+
+				// Set the template selector to match the tag from the test case
+				dm.Spec.TemplateSource.SourceNode = ""
+				dm.Spec.TemplateSource.TemplateID = nil
+				dm.Spec.TemplateSelector = &TemplateSelector{MatchTags: []string{testCase.tag}}
+
+				// Run test
+				if !testCase.expectErrror {
+					Expect(k8sClient.Create(context.Background(), dm)).To(Succeed())
+				} else {
+					Expect(k8sClient.Create(context.Background(), dm)).Should(MatchError(ContainSubstring(testCase.errorMessage)))
+				}
+			}
+		})
 	})
 
 	Context("Disks", func() {

config/crd/bases/infrastructure.cluster.x-k8s.io_proxmoxclusters.yaml

@@ -569,9 +569,11 @@ spec:
                                 Passed tags must be an exact 1:1 match with the tags on the template you want to use.
                                 If multiple VM templates with the same set of tags are found, provisioning will fail.
                               items:
+                                pattern: ^(?i)[a-z0-9_][a-z0-9_\-\+\.]*$
                                 type: string
                               minItems: 1
                               type: array
+                              x-kubernetes-list-type: set
                           required:
                           - matchTags
                           type: object

config/crd/bases/infrastructure.cluster.x-k8s.io_proxmoxclustertemplates.yaml

@@ -610,9 +610,11 @@ spec:
                                         Passed tags must be an exact 1:1 match with the tags on the template you want to use.
                                         If multiple VM templates with the same set of tags are found, provisioning will fail.
                                       items:
+                                        pattern: ^(?i)[a-z0-9_][a-z0-9_\-\+\.]*$
                                         type: string
                                       minItems: 1
                                       type: array
+                                      x-kubernetes-list-type: set
                                   required:
                                   - matchTags
                                   type: object

config/crd/bases/infrastructure.cluster.x-k8s.io_proxmoxmachines.yaml

@@ -537,9 +537,11 @@ spec:
                       Passed tags must be an exact 1:1 match with the tags on the template you want to use.
                       If multiple VM templates with the same set of tags are found, provisioning will fail.
                     items:
+                      pattern: ^(?i)[a-z0-9_][a-z0-9_\-\+\.]*$
                       type: string
                     minItems: 1
                     type: array
+                    x-kubernetes-list-type: set
                 required:
                 - matchTags
                 type: object

config/crd/bases/infrastructure.cluster.x-k8s.io_proxmoxmachinetemplates.yaml

@@ -569,9 +569,11 @@ spec:
                               Passed tags must be an exact 1:1 match with the tags on the template you want to use.
                               If multiple VM templates with the same set of tags are found, provisioning will fail.
                             items:
+                              pattern: ^(?i)[a-z0-9_][a-z0-9_\-\+\.]*$
                               type: string
                             minItems: 1
                             type: array
+                            x-kubernetes-list-type: set
                         required:
                         - matchTags
                         type: object