Handle empty strings in config values

ec/ecresource/deploymentresource/apm/v2/schema.go

@@ -45,18 +45,30 @@ func ApmConfigSchema() schema.Attribute {
 			"user_settings_json": schema.StringAttribute{
 				Description: `An arbitrary JSON object allowing (non-admin) cluster owners to set their parameters (only one of this and 'user_settings_yaml' is allowed), provided they are on the whitelist ('user_settings_whitelist') and not on the blacklist ('user_settings_blacklist'). (This field together with 'user_settings_override*' and 'system_settings' defines the total set of resource settings)`,
 				Optional:    true,
+				PlanModifiers: []planmodifier.String{
+					planmodifiers.SetNullWhenEmptyString(),
+				},
 			},
 			"user_settings_override_json": schema.StringAttribute{
 				Description: `An arbitrary JSON object allowing ECE admins owners to set clusters' parameters (only one of this and 'user_settings_override_yaml' is allowed), ie in addition to the documented 'system_settings'. (This field together with 'system_settings' and 'user_settings*' defines the total set of resource settings)`,
 				Optional:    true,
+				PlanModifiers: []planmodifier.String{
+					planmodifiers.SetNullWhenEmptyString(),
+				},
 			},
 			"user_settings_yaml": schema.StringAttribute{
 				Description: `An arbitrary YAML object allowing (non-admin) cluster owners to set their parameters (only one of this and 'user_settings_json' is allowed), provided they are on the whitelist ('user_settings_whitelist') and not on the blacklist ('user_settings_blacklist'). (These field together with 'user_settings_override*' and 'system_settings' defines the total set of resource settings)`,
 				Optional:    true,
+				PlanModifiers: []planmodifier.String{
+					planmodifiers.SetNullWhenEmptyString(),
+				},
 			},
 			"user_settings_override_yaml": schema.StringAttribute{
 				Description: `An arbitrary YAML object allowing ECE admins owners to set clusters' parameters (only one of this and 'user_settings_override_json' is allowed), ie in addition to the documented 'system_settings'. (This field together with 'system_settings' and 'user_settings*' defines the total set of resource settings)`,
 				Optional:    true,
+				PlanModifiers: []planmodifier.String{
+					planmodifiers.SetNullWhenEmptyString(),
+				},
 			},
 		},
 	}

ec/ecresource/deploymentresource/elasticsearch/v2/schema.go

@@ -175,18 +175,30 @@ func elasticsearchConfigSchema() schema.Attribute {
 			"user_settings_json": schema.StringAttribute{
 				Description: `JSON-formatted user level "elasticsearch.yml" setting overrides`,
 				Optional:    true,
+				PlanModifiers: []planmodifier.String{
+					planmodifiers.SetNullWhenEmptyString(),
+				},
 			},
 			"user_settings_override_json": schema.StringAttribute{
 				Description: `JSON-formatted admin (ECE) level "elasticsearch.yml" setting overrides`,
 				Optional:    true,
+				PlanModifiers: []planmodifier.String{
+					planmodifiers.SetNullWhenEmptyString(),
+				},
 			},
 			"user_settings_yaml": schema.StringAttribute{
 				Description: `YAML-formatted user level "elasticsearch.yml" setting overrides`,
 				Optional:    true,
+				PlanModifiers: []planmodifier.String{
+					planmodifiers.SetNullWhenEmptyString(),
+				},
 			},
 			"user_settings_override_yaml": schema.StringAttribute{
 				Description: `YAML-formatted admin (ECE) level "elasticsearch.yml" setting overrides`,
 				Optional:    true,
+				PlanModifiers: []planmodifier.String{
+					planmodifiers.SetNullWhenEmptyString(),
+				},
 			},
 		},
 	}

ec/ecresource/deploymentresource/enterprisesearch/v2/schema.go

@@ -127,18 +127,30 @@ func EnterpriseSearchSchema() schema.Attribute {
 					"user_settings_json": schema.StringAttribute{
 						Description: `An arbitrary JSON object allowing (non-admin) cluster owners to set their parameters (only one of this and 'user_settings_yaml' is allowed), provided they are on the whitelist ('user_settings_whitelist') and not on the blacklist ('user_settings_blacklist'). (This field together with 'user_settings_override*' and 'system_settings' defines the total set of resource settings)`,
 						Optional:    true,
+						PlanModifiers: []planmodifier.String{
+							planmodifiers.SetNullWhenEmptyString(),
+						},
 					},
 					"user_settings_override_json": schema.StringAttribute{
 						Description: `An arbitrary JSON object allowing ECE admins owners to set clusters' parameters (only one of this and 'user_settings_override_yaml' is allowed), ie in addition to the documented 'system_settings'. (This field together with 'system_settings' and 'user_settings*' defines the total set of resource settings)`,
 						Optional:    true,
+						PlanModifiers: []planmodifier.String{
+							planmodifiers.SetNullWhenEmptyString(),
+						},
 					},
 					"user_settings_yaml": schema.StringAttribute{
 						Description: `An arbitrary YAML object allowing (non-admin) cluster owners to set their parameters (only one of this and 'user_settings_json' is allowed), provided they are on the whitelist ('user_settings_whitelist') and not on the blacklist ('user_settings_blacklist'). (These field together with 'user_settings_override*' and 'system_settings' defines the total set of resource settings)`,
 						Optional:    true,
+						PlanModifiers: []planmodifier.String{
+							planmodifiers.SetNullWhenEmptyString(),
+						},
 					},
 					"user_settings_override_yaml": schema.StringAttribute{
 						Description: `An arbitrary YAML object allowing ECE admins owners to set clusters' parameters (only one of this and 'user_settings_override_json' is allowed), ie in addition to the documented 'system_settings'. (This field together with 'system_settings' and 'user_settings*' defines the total set of resource settings)`,
 						Optional:    true,
+						PlanModifiers: []planmodifier.String{
+							planmodifiers.SetNullWhenEmptyString(),
+						},
 					},
 				},
 			},

ec/ecresource/deploymentresource/integrationsserver/v2/schema.go

@@ -131,18 +131,30 @@ func IntegrationsServerSchema() schema.Attribute {
 					"user_settings_json": schema.StringAttribute{
 						Description: `An arbitrary JSON object allowing (non-admin) cluster owners to set their parameters (only one of this and 'user_settings_yaml' is allowed), provided they are on the whitelist ('user_settings_whitelist') and not on the blacklist ('user_settings_blacklist'). (This field together with 'user_settings_override*' and 'system_settings' defines the total set of resource settings)`,
 						Optional:    true,
+						PlanModifiers: []planmodifier.String{
+							planmodifiers.SetNullWhenEmptyString(),
+						},
 					},
 					"user_settings_override_json": schema.StringAttribute{
 						Description: `An arbitrary JSON object allowing ECE admins owners to set clusters' parameters (only one of this and 'user_settings_override_yaml' is allowed), ie in addition to the documented 'system_settings'. (This field together with 'system_settings' and 'user_settings*' defines the total set of resource settings)`,
 						Optional:    true,
+						PlanModifiers: []planmodifier.String{
+							planmodifiers.SetNullWhenEmptyString(),
+						},
 					},
 					"user_settings_yaml": schema.StringAttribute{
 						Description: `An arbitrary YAML object allowing (non-admin) cluster owners to set their parameters (only one of this and 'user_settings_json' is allowed), provided they are on the whitelist ('user_settings_whitelist') and not on the blacklist ('user_settings_blacklist'). (These field together with 'user_settings_override*' and 'system_settings' defines the total set of resource settings)`,
 						Optional:    true,
+						PlanModifiers: []planmodifier.String{
+							planmodifiers.SetNullWhenEmptyString(),
+						},
 					},
 					"user_settings_override_yaml": schema.StringAttribute{
 						Description: `An arbitrary YAML object allowing ECE admins owners to set clusters' parameters (only one of this and 'user_settings_override_json' is allowed), ie in addition to the documented 'system_settings'. (This field together with 'system_settings' and 'user_settings*' defines the total set of resource settings)`,
 						Optional:    true,
+						PlanModifiers: []planmodifier.String{
+							planmodifiers.SetNullWhenEmptyString(),
+						},
 					},
 				},
 			},

ec/ecresource/deploymentresource/kibana/v2/schema.go

@@ -110,18 +110,30 @@ func KibanaSchema() schema.Attribute {
 					"user_settings_json": schema.StringAttribute{
 						Description: `An arbitrary JSON object allowing (non-admin) cluster owners to set their parameters (only one of this and 'user_settings_yaml' is allowed), provided they are on the whitelist ('user_settings_whitelist') and not on the blacklist ('user_settings_blacklist'). (This field together with 'user_settings_override*' and 'system_settings' defines the total set of resource settings)`,
 						Optional:    true,
+						PlanModifiers: []planmodifier.String{
+							planmodifiers.SetNullWhenEmptyString(),
+						},
 					},
 					"user_settings_override_json": schema.StringAttribute{
 						Description: `An arbitrary JSON object allowing ECE admins owners to set clusters' parameters (only one of this and 'user_settings_override_yaml' is allowed), ie in addition to the documented 'system_settings'. (This field together with 'system_settings' and 'user_settings*' defines the total set of resource settings)`,
 						Optional:    true,
+						PlanModifiers: []planmodifier.String{
+							planmodifiers.SetNullWhenEmptyString(),
+						},
 					},
 					"user_settings_yaml": schema.StringAttribute{
 						Description: `An arbitrary YAML object allowing (non-admin) cluster owners to set their parameters (only one of this and 'user_settings_json' is allowed), provided they are on the whitelist ('user_settings_whitelist') and not on the blacklist ('user_settings_blacklist'). (These field together with 'user_settings_override*' and 'system_settings' defines the total set of resource settings)`,
 						Optional:    true,
+						PlanModifiers: []planmodifier.String{
+							planmodifiers.SetNullWhenEmptyString(),
+						},
 					},
 					"user_settings_override_yaml": schema.StringAttribute{
 						Description: `An arbitrary YAML object allowing ECE admins owners to set clusters' parameters (only one of this and 'user_settings_override_json' is allowed), ie in addition to the documented 'system_settings'. (This field together with 'system_settings' and 'user_settings*' defines the total set of resource settings)`,
 						Optional:    true,
+						PlanModifiers: []planmodifier.String{
+							planmodifiers.SetNullWhenEmptyString(),
+						},
 					},
 				},
 			},

ec/internal/planmodifiers/set_null_when_empty_string.go

@@ -0,0 +1,53 @@
+// Licensed to Elasticsearch B.V. under one or more contributor
+// license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright
+// ownership. Elasticsearch B.V. licenses this file to you under
+// the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+package planmodifiers
+
+import (
+	"context"
+
+	"github.com/hashicorp/terraform-plugin-framework/resource/schema/planmodifier"
+	"github.com/hashicorp/terraform-plugin-framework/types"
+)
+
+func SetNullWhenEmptyString() planmodifier.String {
+	return setNullWhenEmptyString{}
+}
+
+type setNullWhenEmptyString struct{}
+
+func (m setNullWhenEmptyString) PlanModifyString(ctx context.Context, req planmodifier.StringRequest, resp *planmodifier.StringResponse) {
+	if req.PlanValue.IsNull() || req.PlanValue.IsUnknown() {
+		return
+	}
+
+	if req.PlanValue.ValueString() != "" {
+		return
+	}
+
+	resp.PlanValue = types.StringNull()
+}
+
+// Description returns a human-readable description of the plan modifier.
+func (r setNullWhenEmptyString) Description(ctx context.Context) string {
+	return "Set the plan value to null if currently configured to null."
+}
+
+// MarkdownDescription returns a markdown description of the plan modifier.
+func (r setNullWhenEmptyString) MarkdownDescription(ctx context.Context) string {
+	return "Set the plan value to null if currently configured to null."
+}

ec/internal/planmodifiers/set_null_when_empty_string_test.go

@@ -0,0 +1,72 @@
+// Licensed to Elasticsearch B.V. under one or more contributor
+// license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright
+// ownership. Elasticsearch B.V. licenses this file to you under
+// the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+package planmodifiers_test
+
+import (
+	"context"
+	"testing"
+
+	"github.com/elastic/terraform-provider-ec/ec/internal/planmodifiers"
+	"github.com/hashicorp/terraform-plugin-framework/resource/schema/planmodifier"
+	"github.com/hashicorp/terraform-plugin-framework/types"
+	"github.com/stretchr/testify/require"
+)
+
+func TestSetNullWhenEmptyString(t *testing.T) {
+	tests := []struct {
+		name              string
+		planValue         types.String
+		expectedPlanValue types.String
+	}{
+		{
+			name:              "should do nothing when the plan value is null",
+			planValue:         types.StringNull(),
+			expectedPlanValue: types.StringNull(),
+		},
+		{
+			name:              "should do nothing when the plan value is unknown",
+			planValue:         types.StringUnknown(),
+			expectedPlanValue: types.StringUnknown(),
+		},
+		{
+			name:              "should do nothing when the plan value is not empty",
+			planValue:         types.StringValue("hello"),
+			expectedPlanValue: types.StringValue("hello"),
+		},
+		{
+			name:              "should set the plan value to null when the plan value is empty",
+			planValue:         types.StringValue(""),
+			expectedPlanValue: types.StringNull(),
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			modifier := planmodifiers.SetNullWhenEmptyString()
+
+			resp := planmodifier.StringResponse{
+				PlanValue: tt.planValue,
+			}
+			modifier.PlanModifyString(context.Background(), planmodifier.StringRequest{
+				PlanValue: tt.planValue,
+			}, &resp)
+
+			require.Equal(t, tt.expectedPlanValue, resp.PlanValue)
+		})
+	}
+}