unify regexp usage across codebase (gardener#8379)

* unify regexp usage across codebase

* address PR feedback

extensions/pkg/controller/healthcheck/general/managed_resource.go

@@ -62,6 +62,9 @@ func (healthChecker *ManagedResourceHealthChecker) DeepCopy() healthcheck.Health
 	return &shallowCopy
 }
 
+// configurationProblemRegex is used to check if a not healthy managed resource has a configuration problem.
+var configurationProblemRegex = regexp.MustCompile(`(?i)(error during apply of object .* is invalid:)`)
+
 // Check executes the health check
 func (healthChecker *ManagedResourceHealthChecker) Check(ctx context.Context, request types.NamespacedName) (*healthcheck.SingleCheckResult, error) {
 	mcmDeployment := &resourcesv1alpha1.ManagedResource{}
@@ -81,12 +84,8 @@ func (healthChecker *ManagedResourceHealthChecker) Check(ctx context.Context, re
 	if isHealthy, err := managedResourceIsHealthy(mcmDeployment); !isHealthy {
 		healthChecker.logger.Error(err, "Health check failed")
 
-		var (
-			errorCodes                 []gardencorev1beta1.ErrorCode
-			configurationProblemRegexp = regexp.MustCompile(`(?i)(error during apply of object .* is invalid:)`)
-		)
-
-		if configurationProblemRegexp.MatchString(err.Error()) {
+		var errorCodes []gardencorev1beta1.ErrorCode
+		if configurationProblemRegex.MatchString(err.Error()) {
 			errorCodes = append(errorCodes, gardencorev1beta1.ErrorConfigurationProblem)
 		}
 

extensions/pkg/controller/worker/machines.go

@@ -23,7 +23,6 @@ import (
 	machinev1alpha1 "github.com/gardener/machine-controller-manager/pkg/apis/machine/v1alpha1"
 	corev1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/util/intstr"
-	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
 
 	extensionscontroller "github.com/gardener/gardener/extensions/pkg/controller"
 	"github.com/gardener/gardener/extensions/pkg/util"
@@ -33,13 +32,7 @@ import (
 	"github.com/gardener/gardener/pkg/utils"
 )
 
-var diskSizeRegexp *regexp.Regexp
-
-func init() {
-	regexp, err := regexp.Compile(`^(\d+)`)
-	utilruntime.Must(err)
-	diskSizeRegexp = regexp
-}
+var diskSizeRegex = regexp.MustCompile(`^(\d+)`)
 
 // MachineDeployment holds information about the name, class, replicas of a MachineDeployment
 // managed by the machine-controller-manager.
@@ -237,7 +230,7 @@ func DistributePositiveIntOrPercent(zoneIndex int32, intOrPercent intstr.IntOrSt
 // DiskSize extracts the numerical component of DiskSize strings, i.e. strings like "10Gi" and
 // returns it as string, i.e. "10" will be returned.
 func DiskSize(size string) (int, error) {
-	i, err := strconv.Atoi(diskSizeRegexp.FindString(size))
+	i, err := strconv.Atoi(diskSizeRegex.FindString(size))
 	if err != nil {
 		return -1, err
 	}

extensions/pkg/terraformer/errors.go

@@ -20,14 +20,16 @@ import (
 	"strings"
 )
 
+var (
+	regexTerraformError = regexp.MustCompile(`(?:Error): *([\s\S]*)`)
+	regexUUID           = regexp.MustCompile(`(?i)[0-9a-f]{8}(?:-[0-9a-f]{4}){3}-[0-9a-f]{12}`)
+	regexMultiNewline   = regexp.MustCompile(`\n{2,}`)
+)
+
 // findTerraformErrors gets the <output> of a Terraform run and parses it to find the occurred
 // errors (which will be returned). If no errors occurred, an empty string will be returned.
 func findTerraformErrors(output string) string {
 	var (
-		regexTerraformError = regexp.MustCompile(`(?:Error): *([\s\S]*)`)
-		regexUUID           = regexp.MustCompile(`(?i)[0-9a-f]{8}(?:-[0-9a-f]{4}){3}-[0-9a-f]{12}`)
-		regexMultiNewline   = regexp.MustCompile(`\n{2,}`)
-
 		errorMessage = output
 		valid        []string
 	)

extensions/pkg/webhook/utils.go

@@ -42,10 +42,13 @@ func AppendUniqueUnit(units *[]extensionsv1alpha1.Unit, unit extensionsv1alpha1.
 	*units = append(*units, unit)
 }
 
+// splitCommandLineRegex is used to split command line arguments by white space or "\".
+var splitCommandLineRegex = regexp.MustCompile(`[\\\s]+`)
+
 // DeserializeCommandLine de-serializes the given string to a slice of command line elements by splitting it
 // on white space and the "\" character.
 func DeserializeCommandLine(s string) []string {
-	return regexp.MustCompile(`[\\\s]+`).Split(s, -1)
+	return splitCommandLineRegex.Split(s, -1)
 }
 
 // SerializeCommandLine serializes the given command line elements slice to a string by joining the first

pkg/apis/core/validation/cloudprofile.go

@@ -86,6 +86,9 @@ func ValidateCloudProfileSpec(spec *core.CloudProfileSpec, fldPath *field.Path)
 	return allErrs
 }
 
+// k8sVersionCPRegex is used to validate kubernetes versions in a cloud profile.
+var k8sVersionCPRegex = regexp.MustCompile(`^([0-9]+\.){2}[0-9]+$`)
+
 func validateKubernetesSettings(kubernetes core.KubernetesSettings, fldPath *field.Path) field.ErrorList {
 	allErrs := field.ErrorList{}
 	if len(kubernetes.Versions) == 0 {
@@ -100,11 +103,10 @@ func validateKubernetesSettings(kubernetes core.KubernetesSettings, fldPath *fie
 	}
 
 	versionsFound := sets.New[string]()
-	r, _ := regexp.Compile(`^([0-9]+\.){2}[0-9]+$`)
 	for i, version := range kubernetes.Versions {
 		idxPath := fldPath.Child("versions").Index(i)
-		if !r.MatchString(version.Version) {
-			allErrs = append(allErrs, field.Invalid(idxPath, version, fmt.Sprintf("all Kubernetes versions must match the regex %s", r)))
+		if !k8sVersionCPRegex.MatchString(version.Version) {
+			allErrs = append(allErrs, field.Invalid(idxPath, version, fmt.Sprintf("all Kubernetes versions must match the regex %s", k8sVersionCPRegex)))
 		} else if versionsFound.Has(version.Version) {
 			allErrs = append(allErrs, field.Duplicate(idxPath.Child("version"), version.Version))
 		} else {

pkg/apis/core/validation/shoot.go

@@ -1412,6 +1412,9 @@ const (
 	maxVolumeNameLength = 15
 )
 
+// volumeSizeRegex is used for volume size validation.
+var volumeSizeRegex = regexp.MustCompile(`^(\d)+Gi$`)
+
 // ValidateWorker validates the worker object.
 func ValidateWorker(worker core.Worker, kubernetes core.Kubernetes, fldPath *field.Path, inTemplate bool) field.ErrorList {
 	kubernetesVersion := kubernetes.Version
@@ -1476,8 +1479,6 @@ func ValidateWorker(worker core.Worker, kubernetes core.Kubernetes, fldPath *fie
 		}
 	}
 
-	volumeSizeRegex, _ := regexp.Compile(`^(\d)+Gi$`)
-
 	if worker.Volume != nil {
 		if !volumeSizeRegex.MatchString(worker.Volume.VolumeSize) {
 			allErrs = append(allErrs, field.Invalid(fldPath.Child("volume", "size"), worker.Volume.VolumeSize, fmt.Sprintf("volume size must match the regex %s", volumeSizeRegex)))

pkg/operation/botanist/secrets.go

@@ -278,6 +278,9 @@ func (b *Botanist) generateSSHKeypair(ctx context.Context) error {
 	return nil
 }
 
+// quotaExceededRegex is used to check if an error occurred due to infrastructure quota limits.
+var quotaExceededRegex = regexp.MustCompile(`(?i)((?:^|[^t]|(?:[^s]|^)t|(?:[^e]|^)st|(?:[^u]|^)est|(?:[^q]|^)uest|(?:[^e]|^)quest|(?:[^r]|^)equest)LimitExceeded|Quotas|Quota.*exceeded|exceeded quota|Quota has been met|QUOTA_EXCEEDED)`)
+
 func (b *Botanist) syncShootCredentialToGarden(
 	ctx context.Context,
 	nameSuffix string,
@@ -303,8 +306,7 @@ func (b *Botanist) syncShootCredentialToGarden(
 		return nil
 	})
 
-	quotaExceededRegexp := regexp.MustCompile(`(?i)((?:^|[^t]|(?:[^s]|^)t|(?:[^e]|^)st|(?:[^u]|^)est|(?:[^q]|^)uest|(?:[^e]|^)quest|(?:[^r]|^)equest)LimitExceeded|Quotas|Quota.*exceeded|exceeded quota|Quota has been met|QUOTA_EXCEEDED)`)
-	if err != nil && quotaExceededRegexp.MatchString(err.Error()) {
+	if err != nil && quotaExceededRegex.MatchString(err.Error()) {
 		return v1beta1helper.NewErrorWithCodes(err, gardencorev1beta1.ErrorInfraQuotaExceeded)
 	}
 	return err

pkg/operation/care/checker.go

@@ -197,16 +197,18 @@ func (b *HealthChecker) checkStatefulSets(condition gardencorev1beta1.Condition,
 	return nil
 }
 
+// kubeletConfigProblemRegex is used to check if an error occurred due to a kubelet configuration problem.
+var kubeletConfigProblemRegex = regexp.MustCompile(`(?i)(KubeletHasInsufficientMemory|KubeletHasDiskPressure|KubeletHasInsufficientPID)`)
+
 func (b *HealthChecker) checkNodes(condition gardencorev1beta1.Condition, nodes []corev1.Node, workerGroupName string, workerGroupKubernetesVersion *semver.Version) *gardencorev1beta1.Condition {
 	for _, object := range nodes {
 		if err := health.CheckNode(&object); err != nil {
 			var (
-				errorCodes                 []gardencorev1beta1.ErrorCode
-				message                    = fmt.Sprintf("Node %q in worker group %q is unhealthy: %v", object.Name, workerGroupName, err)
-				configurationProblemRegexp = regexp.MustCompile(`(?i)(KubeletHasInsufficientMemory|KubeletHasDiskPressure|KubeletHasInsufficientPID)`)
+				errorCodes []gardencorev1beta1.ErrorCode
+				message    = fmt.Sprintf("Node %q in worker group %q is unhealthy: %v", object.Name, workerGroupName, err)
 			)
 
-			if configurationProblemRegexp.MatchString(err.Error()) {
+			if kubeletConfigProblemRegex.MatchString(err.Error()) {
 				errorCodes = append(errorCodes, gardencorev1beta1.ErrorConfigurationProblem)
 			}
 

pkg/resourcemanager/controller/networkpolicy/reconciler.go

@@ -39,11 +39,7 @@ import (
 	kubernetesutils "github.com/gardener/gardener/pkg/utils/kubernetes"
 )
 
-var fromPolicyRegexp *regexp.Regexp
-
-func init() {
-	fromPolicyRegexp = regexp.MustCompile(resourcesv1alpha1.NetworkPolicyFromPolicyAnnotationPrefix + "(.*)" + resourcesv1alpha1.NetworkPolicyFromPolicyAnnotationSuffix)
-}
+var fromPolicyRegexp = regexp.MustCompile(resourcesv1alpha1.NetworkPolicyFromPolicyAnnotationPrefix + "(.*)" + resourcesv1alpha1.NetworkPolicyFromPolicyAnnotationSuffix)
 
 // Reconciler reconciles Service objects and creates NetworkPolicy objects.
 type Reconciler struct {

pkg/utils/kubernetes/bootstraptoken/bootstraptoken.go

@@ -30,6 +30,9 @@ import (
 	"github.com/gardener/gardener/pkg/utils/kubernetes"
 )
 
+// validBootstrapTokenRegex is used to check if an existing token can be interpreted as a bootstrap token.
+var validBootstrapTokenRegex = regexp.MustCompile(`[a-z0-9]{16}`)
+
 // ComputeBootstrapToken computes and creates a new bootstrap token, and returns it.
 func ComputeBootstrapToken(ctx context.Context, c client.Client, tokenID, description string, validity time.Duration) (secret *corev1.Secret, err error) {
 	var (
@@ -47,8 +50,7 @@ func ComputeBootstrapToken(ctx context.Context, c client.Client, tokenID, descri
 		return nil, err
 	}
 
-	validBootstrapTokenSecret, _ := regexp.Compile(`[a-z0-9]{16}`)
-	if existingSecretToken, ok := secret.Data[bootstraptokenapi.BootstrapTokenSecretKey]; ok && validBootstrapTokenSecret.Match(existingSecretToken) {
+	if existingSecretToken, ok := secret.Data[bootstraptokenapi.BootstrapTokenSecretKey]; ok && validBootstrapTokenRegex.Match(existingSecretToken) {
 		bootstrapTokenSecretKey = string(existingSecretToken)
 	} else {
 		bootstrapTokenSecretKey, err = utils.GenerateRandomStringFromCharset(16, "0123456789abcdefghijklmnopqrstuvwxyz")

pkg/utils/managedresources/managedresources.go

@@ -352,13 +352,12 @@ func RenderChartAndCreate(ctx context.Context, namespace string, name string, se
 	return Create(ctx, client, namespace, name, nil, secretNameWithPrefix, "", map[string][]byte{chartName: data}, pointer.Bool(false), injectedLabels, &forceOverwriteAnnotations)
 }
 
-func checkConfigurationError(err error) []gardencorev1beta1.ErrorCode {
-	var (
-		errorCodes                 []gardencorev1beta1.ErrorCode
-		configurationProblemRegexp = regexp.MustCompile(`(?i)(error during apply of object .* is invalid:)`)
-	)
+// configurationProblemRegex is used to check if an error is caused by a bad managed resource configuration.
+var configurationProblemRegex = regexp.MustCompile(`(?i)(error during apply of object .* is invalid:)`)
 
-	if configurationProblemRegexp.MatchString(err.Error()) {
+func checkConfigurationError(err error) []gardencorev1beta1.ErrorCode {
+	var errorCodes []gardencorev1beta1.ErrorCode
+	if configurationProblemRegex.MatchString(err.Error()) {
 		errorCodes = append(errorCodes, gardencorev1beta1.ErrorConfigurationProblem)
 	}
 

pkg/utils/miscellaneous.go

@@ -118,10 +118,12 @@ func FindFreePort() (int, error) {
 	return l.Addr().(*net.TCPAddr).Port, nil
 }
 
+// emailVefiryRegex is used to verify the validity of an email.
+var emailVefiryRegex = regexp.MustCompile(`^[^@]+@(?:[a-zA-Z-0-9]+\.)+[a-zA-Z]{2,}$`)
+
 // TestEmail validates the provided <email> against a regular expression and returns whether it matches.
 func TestEmail(email string) bool {
-	match, _ := regexp.MatchString(`^[^@]+@(?:[a-zA-Z-0-9]+\.)+[a-zA-Z]{2,}$`, email)
-	return match
+	return emailVefiryRegex.MatchString(email)
 }
 
 // IDForKeyWithOptionalValue returns an identifier for the given key + optional value.

test/framework/reporter/esreporter.go

@@ -82,7 +82,7 @@ type GardenerESReporter struct {
 	index    []byte
 }
 
-var matchLabel, _ = regexp.Compile(`\\[(.*?)\\]`)
+var matchLabel = regexp.MustCompile(`\\[(.*?)\\]`)
 
 // newGardenerESReporter creates a new Gardener elasticsearch reporter.
 // Any report will be encoded to json and stored to the passed filename in the given es index.