fix(postgresflex): prevent state drifts on cron strings

stackit/internal/services/mongodbflex/instance/resource.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	mongodbflexUtils "github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/mongodbflex/utils"
+	stringplanmodifierCustom "github.com/stackitcloud/terraform-provider-stackit/stackit/internal/utils/planmodifiers/stringplanmodifier"
 
 	"github.com/hashicorp/terraform-plugin-framework-validators/stringvalidator"
 	"github.com/hashicorp/terraform-plugin-framework/attr"
@@ -240,6 +241,9 @@ func (r *instanceResource) Schema(_ context.Context, _ resource.SchemaRequest, r
 			"backup_schedule": schema.StringAttribute{
 				Description: descriptions["backup_schedule"],
 				Required:    true,
+				PlanModifiers: []planmodifier.String{
+					stringplanmodifierCustom.CronNormalizationModifier{},
+				},
 			},
 			"flavor": schema.SingleNestedAttribute{
 				Required: true,
@@ -852,10 +856,11 @@ func mapFields(ctx context.Context, resp *mongodbflex.InstanceResponse, model *M
 		return fmt.Errorf("creating options: %w", core.DiagsToError(diags))
 	}
 
-	simplifiedModelBackupSchedule := utils.SimplifyBackupSchedule(model.BackupSchedule.ValueString())
-	// If the value returned by the API is different from the one in the model after simplification,
-	// we update the model so that it causes an error in Terraform
-	if simplifiedModelBackupSchedule != types.StringPointerValue(instance.BackupSchedule).ValueString() {
+	// If the API returned "0 0 * * *" but user defined "00 00 * * *" in its config,
+	// we keep the user's "00 00 * * *" in the state to satisfy Terraform.
+	backupScheduleApiResp := types.StringPointerValue(instance.BackupSchedule)
+	if utils.SimplifyCronString(model.BackupSchedule.ValueString()) != utils.SimplifyCronString(backupScheduleApiResp.ValueString()) {
+		// If the API actually changed it to something else, use the API value
 		model.BackupSchedule = types.StringPointerValue(instance.BackupSchedule)
 	}
 

stackit/internal/services/observability/instance/resource.go

@@ -534,23 +534,23 @@ func (r *instanceResource) Schema(_ context.Context, _ resource.SchemaRequest, r
 				Optional:    true,
 				Computed:    true,
 				PlanModifiers: []planmodifier.Int64{
-					int64planmodifier.UseStateForUnknownIf(utils.Int64Changed, "metrics_retention_days", "sets `UseStateForUnknown` only if `metrics_retention_days` has not changed"),
+					int64planmodifier.UseStateForUnknownIf(int64planmodifier.Int64Changed, "metrics_retention_days", "sets `UseStateForUnknown` only if `metrics_retention_days` has not changed"),
 				},
 			},
 			"metrics_retention_days_5m_downsampling": schema.Int64Attribute{
 				Description: "Specifies for how many days the 5m downsampled metrics are kept. must be less than the value of the general retention. Default is set to `90`.",
 				Optional:    true,
 				Computed:    true,
 				PlanModifiers: []planmodifier.Int64{
-					int64planmodifier.UseStateForUnknownIf(utils.Int64Changed, "metrics_retention_days_5m_downsampling", "sets `UseStateForUnknown` only if `metrics_retention_days_5m_downsampling` has not changed"),
+					int64planmodifier.UseStateForUnknownIf(int64planmodifier.Int64Changed, "metrics_retention_days_5m_downsampling", "sets `UseStateForUnknown` only if `metrics_retention_days_5m_downsampling` has not changed"),
 				},
 			},
 			"metrics_retention_days_1h_downsampling": schema.Int64Attribute{
 				Description: "Specifies for how many days the 1h downsampled metrics are kept. must be less than the value of the 5m downsampling retention. Default is set to `90`.",
 				Optional:    true,
 				Computed:    true,
 				PlanModifiers: []planmodifier.Int64{
-					int64planmodifier.UseStateForUnknownIf(utils.Int64Changed, "metrics_retention_days_1h_downsampling", "sets `UseStateForUnknown` only if `metrics_retention_days_1h_downsampling` has not changed"),
+					int64planmodifier.UseStateForUnknownIf(int64planmodifier.Int64Changed, "metrics_retention_days_1h_downsampling", "sets `UseStateForUnknown` only if `metrics_retention_days_1h_downsampling` has not changed"),
 				},
 			},
 			"metrics_url": schema.StringAttribute{

stackit/internal/services/postgresflex/instance/resource.go

@@ -19,6 +19,7 @@ import (
 	"github.com/stackitcloud/terraform-provider-stackit/stackit/internal/conversion"
 	"github.com/stackitcloud/terraform-provider-stackit/stackit/internal/core"
 	"github.com/stackitcloud/terraform-provider-stackit/stackit/internal/utils"
+	stringplanmodifierCustom "github.com/stackitcloud/terraform-provider-stackit/stackit/internal/utils/planmodifiers/stringplanmodifier"
 	"github.com/stackitcloud/terraform-provider-stackit/stackit/internal/validate"
 
 	"github.com/hashicorp/terraform-plugin-framework/resource"
@@ -209,6 +210,9 @@ func (r *instanceResource) Schema(_ context.Context, req resource.SchemaRequest,
 			"backup_schedule": schema.StringAttribute{
 				Description: descriptions["backup_schedule"],
 				Required:    true,
+				PlanModifiers: []planmodifier.String{
+					stringplanmodifierCustom.CronNormalizationModifier{},
+				},
 			},
 			"flavor": schema.SingleNestedAttribute{
 				Required: true,
@@ -652,11 +656,18 @@ func mapFields(ctx context.Context, resp *postgresflex.InstanceResponse, model *
 		return fmt.Errorf("creating storage: %w", core.DiagsToError(diags))
 	}
 
+	// If the API returned "0 0 * * *" but user defined "00 00 * * *" in its config,
+	// we keep the user's "00 00 * * *" in the state to satisfy Terraform.
+	backupScheduleApiResp := types.StringPointerValue(instance.BackupSchedule)
+	if utils.SimplifyCronString(model.BackupSchedule.ValueString()) != utils.SimplifyCronString(backupScheduleApiResp.ValueString()) {
+		// If the API actually changed it to something else, use the API value
+		model.BackupSchedule = types.StringPointerValue(instance.BackupSchedule)
+	}
+
 	model.Id = utils.BuildInternalTerraformId(model.ProjectId.ValueString(), region, instanceId)
 	model.InstanceId = types.StringValue(instanceId)
 	model.Name = types.StringPointerValue(instance.Name)
 	model.ACL = aclList
-	model.BackupSchedule = types.StringPointerValue(instance.BackupSchedule)
 	model.Flavor = flavorObject
 	model.Replicas = types.Int64PointerValue(instance.Replicas)
 	model.Storage = storageObject

stackit/internal/services/postgresflex/instance/resource_test.go

@@ -27,6 +27,37 @@ func (c *postgresFlexClientMocked) ListFlavorsExecute(_ context.Context, _, _ st
 
 func TestMapFields(t *testing.T) {
 	const testRegion = "region"
+
+	fixtureModel := func(mods ...func(*Model)) Model {
+		m := Model{
+			Id:             types.StringValue("pid,region,iid"),
+			InstanceId:     types.StringValue("iid"),
+			ProjectId:      types.StringValue("pid"),
+			Name:           types.StringNull(),
+			ACL:            types.ListNull(types.StringType),
+			BackupSchedule: types.StringNull(),
+			Flavor: types.ObjectValueMust(flavorTypes, map[string]attr.Value{
+				"id":          types.StringNull(),
+				"description": types.StringNull(),
+				"cpu":         types.Int64Null(),
+				"ram":         types.Int64Null(),
+			}),
+			Replicas: types.Int64Null(),
+			Storage: types.ObjectValueMust(storageTypes, map[string]attr.Value{
+				"class": types.StringNull(),
+				"size":  types.Int64Null(),
+			}),
+			Version: types.StringNull(),
+			Region:  types.StringValue(testRegion),
+		}
+
+		for _, mod := range mods {
+			mod(&m)
+		}
+
+		return m
+	}
+
 	tests := []struct {
 		description string
 		state       Model
@@ -49,27 +80,7 @@ func TestMapFields(t *testing.T) {
 			&flavorModel{},
 			&storageModel{},
 			testRegion,
-			Model{
-				Id:             types.StringValue("pid,region,iid"),
-				InstanceId:     types.StringValue("iid"),
-				ProjectId:      types.StringValue("pid"),
-				Name:           types.StringNull(),
-				ACL:            types.ListNull(types.StringType),
-				BackupSchedule: types.StringNull(),
-				Flavor: types.ObjectValueMust(flavorTypes, map[string]attr.Value{
-					"id":          types.StringNull(),
-					"description": types.StringNull(),
-					"cpu":         types.Int64Null(),
-					"ram":         types.Int64Null(),
-				}),
-				Replicas: types.Int64Null(),
-				Storage: types.ObjectValueMust(storageTypes, map[string]attr.Value{
-					"class": types.StringNull(),
-					"size":  types.Int64Null(),
-				}),
-				Version: types.StringNull(),
-				Region:  types.StringValue(testRegion),
-			},
+			fixtureModel(),
 			true,
 		},
 		{
@@ -262,6 +273,42 @@ func TestMapFields(t *testing.T) {
 			},
 			true,
 		},
+		{
+			description: "backup schedule - keep state value when API strips leading zeros",
+			state: fixtureModel(func(m *Model) {
+				m.BackupSchedule = types.StringValue("00 00 * * *")
+			}),
+			input: &postgresflex.InstanceResponse{
+				Item: &postgresflex.Instance{
+					BackupSchedule: utils.Ptr("0 0 * * *"),
+				},
+			},
+			flavor:  &flavorModel{},
+			storage: &storageModel{},
+			region:  testRegion,
+			expected: fixtureModel(func(m *Model) {
+				m.BackupSchedule = types.StringValue("00 00 * * *")
+			}),
+			isValid: true,
+		},
+		{
+			description: "backup schedule - use updated value from API if cron actually changed",
+			state: fixtureModel(func(m *Model) {
+				m.BackupSchedule = types.StringValue("00 01 * * *")
+			}),
+			input: &postgresflex.InstanceResponse{
+				Item: &postgresflex.Instance{
+					BackupSchedule: utils.Ptr("0 2 * * *"),
+				},
+			},
+			flavor:  &flavorModel{},
+			storage: &storageModel{},
+			region:  testRegion,
+			expected: fixtureModel(func(m *Model) {
+				m.BackupSchedule = types.StringValue("0 2 * * *")
+			}),
+			isValid: true,
+		},
 		{
 			"nil_response",
 			Model{

stackit/internal/services/ske/cluster/resource.go

@@ -379,7 +379,7 @@ func (r *clusterResource) Schema(_ context.Context, _ resource.SchemaRequest, re
 				Description: "Full Kubernetes version used. For example, if 1.22 was set in `kubernetes_version_min`, this value may result to 1.22.15. " + SKEUpdateDoc,
 				Computed:    true,
 				PlanModifiers: []planmodifier.String{
-					stringplanmodifierUtils.UseStateForUnknownIf(utils.StringChanged, "kubernetes_version_min", "sets `UseStateForUnknown` only if `kubernetes_min_version` has not changed"),
+					stringplanmodifierUtils.UseStateForUnknownIf(stringplanmodifierUtils.StringChanged, "kubernetes_version_min", "sets `UseStateForUnknown` only if `kubernetes_min_version` has not changed"),
 				},
 			},
 			"egress_address_ranges": schema.ListAttribute{
@@ -462,7 +462,7 @@ func (r *clusterResource) Schema(_ context.Context, _ resource.SchemaRequest, re
 							Description: "Full OS image version used. For example, if 3815.2 was set in `os_version_min`, this value may result to 3815.2.2. " + SKEUpdateDoc,
 							Computed:    true,
 							PlanModifiers: []planmodifier.String{
-								stringplanmodifierUtils.UseStateForUnknownIf(utils.StringChanged, "os_version_min", "sets `UseStateForUnknown` only if `os_version_min` has not changed"),
+								stringplanmodifierUtils.UseStateForUnknownIf(stringplanmodifierUtils.StringChanged, "os_version_min", "sets `UseStateForUnknown` only if `os_version_min` has not changed"),
 							},
 						},
 						"volume_type": schema.StringAttribute{

stackit/internal/services/sqlserverflex/instance/resource.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	sqlserverflexUtils "github.com/stackitcloud/terraform-provider-stackit/stackit/internal/services/sqlserverflex/utils"
+	stringplanmodifierCustom "github.com/stackitcloud/terraform-provider-stackit/stackit/internal/utils/planmodifiers/stringplanmodifier"
 
 	"github.com/hashicorp/terraform-plugin-framework-validators/stringvalidator"
 	"github.com/hashicorp/terraform-plugin-framework/attr"
@@ -230,9 +231,8 @@ func (r *instanceResource) Schema(_ context.Context, _ resource.SchemaRequest, r
 			"backup_schedule": schema.StringAttribute{
 				Description: descriptions["backup_schedule"],
 				Optional:    true,
-				Computed:    true,
 				PlanModifiers: []planmodifier.String{
-					stringplanmodifier.UseStateForUnknown(),
+					stringplanmodifierCustom.CronNormalizationModifier{},
 				},
 			},
 			"flavor": schema.SingleNestedAttribute{
@@ -784,10 +784,11 @@ func mapFields(ctx context.Context, resp *sqlserverflex.GetInstanceResponse, mod
 		return fmt.Errorf("creating options: %w", core.DiagsToError(diags))
 	}
 
-	simplifiedModelBackupSchedule := utils.SimplifyBackupSchedule(model.BackupSchedule.ValueString())
-	// If the value returned by the API is different from the one in the model after simplification,
-	// we update the model so that it causes an error in Terraform
-	if simplifiedModelBackupSchedule != types.StringPointerValue(instance.BackupSchedule).ValueString() {
+	// If the API returned "0 0 * * *" but user defined "00 00 * * *" in its config,
+	// we keep the user's "00 00 * * *" in the state to satisfy Terraform.
+	backupScheduleApiResp := types.StringPointerValue(instance.BackupSchedule)
+	if utils.SimplifyCronString(model.BackupSchedule.ValueString()) != utils.SimplifyCronString(backupScheduleApiResp.ValueString()) {
+		// If the API actually changed it to something else, use the API value
 		model.BackupSchedule = types.StringPointerValue(instance.BackupSchedule)
 	}
 

stackit/internal/utils/attributes.go

@@ -7,11 +7,8 @@ import (
 
 	"github.com/hashicorp/terraform-plugin-framework/diag"
 	"github.com/hashicorp/terraform-plugin-framework/path"
-	"github.com/hashicorp/terraform-plugin-framework/resource/schema/planmodifier"
 	"github.com/hashicorp/terraform-plugin-framework/types"
 	"github.com/stackitcloud/terraform-provider-stackit/stackit/internal/core"
-	"github.com/stackitcloud/terraform-provider-stackit/stackit/internal/utils/planmodifiers/int64planmodifier"
-	"github.com/stackitcloud/terraform-provider-stackit/stackit/internal/utils/planmodifiers/stringplanmodifier"
 )
 
 type attributeGetter interface {
@@ -47,51 +44,3 @@ func GetTimeFromStringAttribute(ctx context.Context, attributePath path.Path, so
 
 	return diags
 }
-
-// Int64Changed sets UseStateForUnkown to true if the attribute's planned value matches the current state
-func Int64Changed(ctx context.Context, attributeName string, request planmodifier.Int64Request, response *int64planmodifier.UseStateForUnknownFuncResponse) { // nolint:gocritic // function signature required by Terraform
-	dependencyPath := request.Path.ParentPath().AtName(attributeName)
-
-	var attributePlan types.Int64
-	diags := request.Plan.GetAttribute(ctx, dependencyPath, &attributePlan)
-	response.Diagnostics.Append(diags...)
-	if response.Diagnostics.HasError() {
-		return
-	}
-
-	var attributeState types.Int64
-	diags = request.State.GetAttribute(ctx, dependencyPath, &attributeState)
-	response.Diagnostics.Append(diags...)
-	if response.Diagnostics.HasError() {
-		return
-	}
-
-	if attributeState == attributePlan {
-		response.UseStateForUnknown = true
-		return
-	}
-}
-
-// StringChanged sets UseStateForUnkown to true if the attribute's planned value matches the current state
-func StringChanged(ctx context.Context, attributeName string, request planmodifier.StringRequest, response *stringplanmodifier.UseStateForUnknownFuncResponse) { // nolint:gocritic // function signature required by Terraform
-	dependencyPath := request.Path.ParentPath().AtName(attributeName)
-
-	var attributePlan types.String
-	diags := request.Plan.GetAttribute(ctx, dependencyPath, &attributePlan)
-	response.Diagnostics.Append(diags...)
-	if response.Diagnostics.HasError() {
-		return
-	}
-
-	var attributeState types.String
-	diags = request.State.GetAttribute(ctx, dependencyPath, &attributeState)
-	response.Diagnostics.Append(diags...)
-	if response.Diagnostics.HasError() {
-		return
-	}
-
-	if attributeState == attributePlan {
-		response.UseStateForUnknown = true
-		return
-	}
-}

stackit/internal/utils/cron.go

@@ -0,0 +1,24 @@
+package utils
+
+import (
+	"regexp"
+	"strings"
+)
+
+// SimplifyCronString removes leading 0s from backup schedule numbers (e.g. "00 00 * * *" becomes "0 0 * * *")
+// Needed as some API might do it internally and would otherwise cause inconsistent result in Terraform
+func SimplifyCronString(cron string) string {
+	regex := regexp.MustCompile(`0+\d+`) // Matches series of one or more zeros followed by a series of one or more digits
+	simplifiedCron := regex.ReplaceAllStringFunc(cron, func(match string) string {
+		simplified := strings.TrimLeft(match, "0")
+		if simplified == "" {
+			simplified = "0"
+		}
+		return simplified
+	})
+
+	whiteSpaceRegex := regexp.MustCompile(`\s+`)
+	simplifiedCron = whiteSpaceRegex.ReplaceAllString(simplifiedCron, " ")
+
+	return simplifiedCron
+}