feat: add skip external request

README.md

@@ -163,13 +163,13 @@ Please ensure that the `MarkdownDescription` field is set in the schema for each
 To generate the documentation run either:
 
 ```sh
-$ make docs
+make docs
 ```
 
 or...
 
 ```sh
-$ go generate ./...
+go generate ./...
 ```
 
 ### Templates
@@ -210,6 +210,16 @@ provider_installation {
 }
 ```
 
+## Developer: Using the `skip_on` struct field tag
+
+The `skip_on` struct field tag is used to skip the external API call when only attributes that affect the internal state are modified, e.g. retry configuration. The `skip_on` struct field tag is used to skip the external API call when only attributes that affect the internal state are modified, e.g. retry configuration. The `skip_on` struct field tag is a comma-separated list of operations that must be met in order to skip the field.
+
+The provider will compare the state with the plan, and check for changes. If the only fields to me modified are those with the `skip_on` struct field tag set to the supplied operation, e.g. `update`, the provider will skip the external API call.
+
+The following operations are supported:
+
+* `update` - Skip the external API call when the operation is an update.
+
 ## Credits
 
 We wish to thank HashiCorp for the use of some MPLv2-licensed code from their open source project [terraform-provider-azurerm](https://github.com/hashicorp/terraform-provider-azurerm).

internal/services/azapi_data_plane_resource.go

@@ -19,6 +19,7 @@ import (
 	"github.com/Azure/terraform-provider-azapi/internal/services/myplanmodifier/planmodifierdynamic"
 	"github.com/Azure/terraform-provider-azapi/internal/services/myvalidator"
 	"github.com/Azure/terraform-provider-azapi/internal/services/parse"
+	"github.com/Azure/terraform-provider-azapi/internal/skip"
 	"github.com/Azure/terraform-provider-azapi/internal/tf"
 	"github.com/Azure/terraform-provider-azapi/utils"
 	"github.com/cenkalti/backoff/v4"
@@ -49,18 +50,18 @@ type DataPlaneResourceModel struct {
 	ReplaceTriggersExternalValues types.Dynamic    `tfsdk:"replace_triggers_external_values"`
 	ReplaceTriggersRefs           types.List       `tfsdk:"replace_triggers_refs"`
 	ResponseExportValues          types.Dynamic    `tfsdk:"response_export_values"`
-	Retry                         retry.RetryValue `tfsdk:"retry"`
+	Retry                         retry.RetryValue `tfsdk:"retry" skip_on:"update"`
 	Locks                         types.List       `tfsdk:"locks"`
 	Output                        types.Dynamic    `tfsdk:"output"`
-	Timeouts                      timeouts.Value   `tfsdk:"timeouts"`
-	CreateHeaders                 types.Map        `tfsdk:"create_headers"`
-	CreateQueryParameters         types.Map        `tfsdk:"create_query_parameters"`
+	Timeouts                      timeouts.Value   `tfsdk:"timeouts" skip_on:"update"`
+	CreateHeaders                 types.Map        `tfsdk:"create_headers" skip_on:"update"`
+	CreateQueryParameters         types.Map        `tfsdk:"create_query_parameters" skip_on:"update"`
 	UpdateHeaders                 types.Map        `tfsdk:"update_headers"`
 	UpdateQueryParameters         types.Map        `tfsdk:"update_query_parameters"`
-	DeleteHeaders                 types.Map        `tfsdk:"delete_headers"`
-	DeleteQueryParameters         types.Map        `tfsdk:"delete_query_parameters"`
-	ReadHeaders                   types.Map        `tfsdk:"read_headers"`
-	ReadQueryParameters           types.Map        `tfsdk:"read_query_parameters"`
+	DeleteHeaders                 types.Map        `tfsdk:"delete_headers" skip_on:"update"`
+	DeleteQueryParameters         types.Map        `tfsdk:"delete_query_parameters" skip_on:"update"`
+	ReadHeaders                   types.Map        `tfsdk:"read_headers" skip_on:"update"`
+	ReadQueryParameters           types.Map        `tfsdk:"read_query_parameters" skip_on:"update"`
 }
 
 type DataPlaneResource struct {
@@ -357,6 +358,19 @@ func (r *DataPlaneResource) Create(ctx context.Context, request resource.CreateR
 }
 
 func (r *DataPlaneResource) Update(ctx context.Context, request resource.UpdateRequest, response *resource.UpdateResponse) {
+	// See if we can skip the external API call (changes are to state only)
+	var state, plan DataPlaneResourceModel
+	if response.Diagnostics.Append(request.Plan.Get(ctx, &plan)...); response.Diagnostics.HasError() {
+		return
+	}
+	if response.Diagnostics.Append(request.State.Get(ctx, &state)...); response.Diagnostics.HasError() {
+		return
+	}
+	if skip.CanSkipExternalRequest(state, plan, "update") {
+		tflog.Debug(ctx, "azapi_resource.CreateUpdate skipping external request as no unskippable changes were detected")
+		response.Diagnostics.Append(response.State.Set(ctx, plan)...)
+	}
+	tflog.Debug(ctx, "azapi_resource.CreateUpdate proceeding with external request as no skippable changes were detected")
 	r.CreateUpdate(ctx, request.Plan, &response.State, &response.Diagnostics)
 }
 

internal/services/azapi_resource.go

@@ -27,6 +27,7 @@ import (
 	"github.com/Azure/terraform-provider-azapi/internal/services/myvalidator"
 	"github.com/Azure/terraform-provider-azapi/internal/services/parse"
 	"github.com/Azure/terraform-provider-azapi/internal/services/preflight"
+	"github.com/Azure/terraform-provider-azapi/internal/skip"
 	"github.com/Azure/terraform-provider-azapi/internal/tf"
 	"github.com/Azure/terraform-provider-azapi/utils"
 	"github.com/cenkalti/backoff/v4"
@@ -63,19 +64,19 @@ type AzapiResourceModel struct {
 	ReplaceTriggersExternalValues types.Dynamic    `tfsdk:"replace_triggers_external_values"`
 	ReplaceTriggersRefs           types.List       `tfsdk:"replace_triggers_refs"`
 	ResponseExportValues          types.Dynamic    `tfsdk:"response_export_values"`
-	Retry                         retry.RetryValue `tfsdk:"retry"`
+	Retry                         retry.RetryValue `tfsdk:"retry" skip_on:"update"`
 	SchemaValidationEnabled       types.Bool       `tfsdk:"schema_validation_enabled"`
 	Tags                          types.Map        `tfsdk:"tags"`
-	Timeouts                      timeouts.Value   `tfsdk:"timeouts"`
+	Timeouts                      timeouts.Value   `tfsdk:"timeouts" skip_on:"update"`
 	Type                          types.String     `tfsdk:"type"`
-	CreateHeaders                 types.Map        `tfsdk:"create_headers"`
-	CreateQueryParameters         types.Map        `tfsdk:"create_query_parameters"`
+	CreateHeaders                 types.Map        `tfsdk:"create_headers" skip_on:"update"`
+	CreateQueryParameters         types.Map        `tfsdk:"create_query_parameters" skip_on:"update"`
 	UpdateHeaders                 types.Map        `tfsdk:"update_headers"`
 	UpdateQueryParameters         types.Map        `tfsdk:"update_query_parameters"`
-	DeleteHeaders                 types.Map        `tfsdk:"delete_headers"`
-	DeleteQueryParameters         types.Map        `tfsdk:"delete_query_parameters"`
-	ReadHeaders                   types.Map        `tfsdk:"read_headers"`
-	ReadQueryParameters           types.Map        `tfsdk:"read_query_parameters"`
+	DeleteHeaders                 types.Map        `tfsdk:"delete_headers" skip_on:"update"`
+	DeleteQueryParameters         types.Map        `tfsdk:"delete_query_parameters" skip_on:"update"`
+	ReadHeaders                   types.Map        `tfsdk:"read_headers" skip_on:"update"`
+	ReadQueryParameters           types.Map        `tfsdk:"read_query_parameters" skip_on:"update"`
 }
 
 var _ resource.Resource = &AzapiResource{}
@@ -588,6 +589,20 @@ func (r *AzapiResource) Create(ctx context.Context, request resource.CreateReque
 }
 
 func (r *AzapiResource) Update(ctx context.Context, request resource.UpdateRequest, response *resource.UpdateResponse) {
+	// See if we can skip the external API call (changes are to state only)
+	var plan, state AzapiResourceModel
+	if response.Diagnostics.Append(request.Plan.Get(ctx, &plan)...); response.Diagnostics.HasError() {
+		return
+	}
+	if response.Diagnostics.Append(request.State.Get(ctx, &state)...); response.Diagnostics.HasError() {
+		return
+	}
+	if skip.CanSkipExternalRequest(plan, state, "update") {
+		response.Diagnostics.Append(response.State.Set(ctx, plan)...)
+		tflog.Debug(ctx, "azapi_resource.CreateUpdate skipping external request as no unskippable changes were detected")
+		return
+	}
+	tflog.Debug(ctx, "azapi_resource.CreateUpdate proceeding with external request as no skippable changes were detected")
 	r.CreateUpdate(ctx, request.Plan, &response.State, &response.Diagnostics)
 }
 

internal/services/azapi_resource_action_resource.go

@@ -16,6 +16,7 @@ import (
 	"github.com/Azure/terraform-provider-azapi/internal/services/myplanmodifier"
 	"github.com/Azure/terraform-provider-azapi/internal/services/myvalidator"
 	"github.com/Azure/terraform-provider-azapi/internal/services/parse"
+	"github.com/Azure/terraform-provider-azapi/internal/skip"
 	"github.com/cenkalti/backoff/v4"
 	"github.com/hashicorp/terraform-plugin-framework-timeouts/resource/timeouts"
 	"github.com/hashicorp/terraform-plugin-framework-validators/listvalidator"
@@ -45,8 +46,8 @@ type ActionResourceModel struct {
 	SensitiveResponseExportValues types.Dynamic    `tfsdk:"sensitive_response_export_values"`
 	Output                        types.Dynamic    `tfsdk:"output"`
 	SensitiveOutput               types.Dynamic    `tfsdk:"sensitive_output"`
-	Timeouts                      timeouts.Value   `tfsdk:"timeouts"`
-	Retry                         retry.RetryValue `tfsdk:"retry"`
+	Timeouts                      timeouts.Value   `tfsdk:"timeouts" skip_on:"update"`
+	Retry                         retry.RetryValue `tfsdk:"retry" skip_on:"update"`
 	Headers                       types.Map        `tfsdk:"headers"`
 	QueryParameters               types.Map        `tfsdk:"query_parameters"`
 }
@@ -280,20 +281,31 @@ func (r *ActionResource) Create(ctx context.Context, request resource.CreateRequ
 }
 
 func (r *ActionResource) Update(ctx context.Context, request resource.UpdateRequest, response *resource.UpdateResponse) {
-	var model ActionResourceModel
-	if response.Diagnostics.Append(request.Plan.Get(ctx, &model)...); response.Diagnostics.HasError() {
+	var state, plan ActionResourceModel
+	if response.Diagnostics.Append(request.Plan.Get(ctx, &plan)...); response.Diagnostics.HasError() {
+		return
+	}
+	if response.Diagnostics.Append(request.State.Get(ctx, &state)...); response.Diagnostics.HasError() {
 		return
 	}
 
-	timeout, diags := model.Timeouts.Update(ctx, 30*time.Minute)
+	timeout, diags := plan.Timeouts.Update(ctx, 30*time.Minute)
 	if response.Diagnostics.Append(diags...); response.Diagnostics.HasError() {
 		return
 	}
 	ctx, cancel := context.WithTimeout(ctx, timeout)
 	defer cancel()
 
-	if model.When.ValueString() == "apply" {
-		r.Action(ctx, model, &response.State, &response.Diagnostics)
+	// See if we can skip the external API call (changes are to state only)
+	if skip.CanSkipExternalRequest(state, plan, "update") {
+		tflog.Debug(ctx, "azapi_resource.CreateUpdate skipping external request as no unskippable changes were detected")
+		response.Diagnostics.Append(response.State.Set(ctx, plan)...)
+		return
+	}
+	tflog.Debug(ctx, "azapi_resource.CreateUpdate proceeding with external request as no skippable changes were detected")
+
+	if plan.When.ValueString() == "apply" {
+		r.Action(ctx, plan, &response.State, &response.Diagnostics)
 	}
 }
 

internal/services/azapi_update_resource.go

@@ -17,6 +17,7 @@ import (
 	"github.com/Azure/terraform-provider-azapi/internal/services/myplanmodifier"
 	"github.com/Azure/terraform-provider-azapi/internal/services/myvalidator"
 	"github.com/Azure/terraform-provider-azapi/internal/services/parse"
+	"github.com/Azure/terraform-provider-azapi/internal/skip"
 	"github.com/Azure/terraform-provider-azapi/utils"
 	"github.com/cenkalti/backoff/v4"
 	"github.com/hashicorp/terraform-plugin-framework-timeouts/resource/timeouts"
@@ -45,12 +46,12 @@ type AzapiUpdateResourceModel struct {
 	ResponseExportValues  types.Dynamic    `tfsdk:"response_export_values"`
 	Locks                 types.List       `tfsdk:"locks"`
 	Output                types.Dynamic    `tfsdk:"output"`
-	Timeouts              timeouts.Value   `tfsdk:"timeouts"`
-	Retry                 retry.RetryValue `tfsdk:"retry"`
+	Timeouts              timeouts.Value   `tfsdk:"timeouts" skip_on:"update"`
+	Retry                 retry.RetryValue `tfsdk:"retry" skip_on:"update"`
 	UpdateHeaders         types.Map        `tfsdk:"update_headers"`
 	UpdateQueryParameters types.Map        `tfsdk:"update_query_parameters"`
-	ReadHeaders           types.Map        `tfsdk:"read_headers"`
-	ReadQueryParameters   types.Map        `tfsdk:"read_query_parameters"`
+	ReadHeaders           types.Map        `tfsdk:"read_headers" skip_on:"update"`
+	ReadQueryParameters   types.Map        `tfsdk:"read_query_parameters" skip_on:"update"`
 }
 
 type AzapiUpdateResource struct {
@@ -302,6 +303,21 @@ func (r *AzapiUpdateResource) Create(ctx context.Context, request resource.Creat
 }
 
 func (r *AzapiUpdateResource) Update(ctx context.Context, request resource.UpdateRequest, response *resource.UpdateResponse) {
+	// See if we can skip the external API call (changes are to state only)
+	var plan, state AzapiUpdateResourceModel
+	if response.Diagnostics.Append(request.Plan.Get(ctx, &plan)...); response.Diagnostics.HasError() {
+		return
+	}
+	if response.Diagnostics.Append(request.State.Get(ctx, &state)...); response.Diagnostics.HasError() {
+		return
+	}
+	if skip.CanSkipExternalRequest(plan, state, "update") {
+		tflog.Debug(ctx, "azapi_resource.CreateUpdate skipping external request as no unskippable changes were detected")
+		response.Diagnostics.Append(request.State.Set(ctx, plan)...)
+		return
+	}
+	tflog.Debug(ctx, "azapi_resource.CreateUpdate proceeding with external request as no skippable changes were detected")
+
 	r.CreateUpdate(ctx, request.Plan, &response.State, &response.Diagnostics)
 }
 

internal/skip/skip.go

@@ -0,0 +1,57 @@
+package skip
+
+import (
+	"reflect"
+	"slices"
+	"strings"
+)
+
+// CanSkipExternalRequest checks if the external request can be skipped based on the plan and state.
+// Two of the same objects are supplied as parameters, together with the operation that is being performed.
+// The function uses the `skip_on` struct tag to determine if the field should be skipped.
+// The value of the `skip_on` tag is a comma-separated list of operations that mean that changes to this field value do not require an external request and are in state only.
+// The function will return true if the external request can be skipped, false otherwise.
+func CanSkipExternalRequest[T any](a, b T, operation string) bool {
+	valA := reflect.ValueOf(a)
+	valB := reflect.ValueOf(b)
+
+	// Since we are using generics, we know that the types of a and b are the same.
+	// Therefore we can check the type of a to determine if it is a struct.
+	if valA.Kind() != reflect.Struct {
+		return false
+	}
+
+	typeOfA := valA.Type()
+	// iterate over all fields of the struct
+	for i := 0; i < typeOfA.NumField(); i++ {
+		field := typeOfA.Field(i)
+		// Check if the field has the skip_on tag
+		// If it doesn't we need to compare the valued as we cannot determine if the field should be skipped.
+		// If the field has the skip_on tag, we can check if the operation is in the list of operations that should be skipped.
+		tag := field.Tag.Get("skip_on")
+		if tag != "" {
+			// Split the tag values by comma and check if the operation is in the list.
+			// If the operation is in the list, then this field represents a change in state only
+			// and does not require an external request to be made.
+			// Therefore we can skip tp the next field.
+			tagValues := strings.Split(tag, ",")
+			if slices.Contains(tagValues, operation) {
+				continue
+			}
+		}
+
+		// If we get here then we need to compare the field values.
+		// By now we have determined that the struct fields do not have a valid skip value for this operation.
+		// Therefore if the field values are not equal, then the external request cannot be skipped.
+		fieldA := valA.Field(i)
+		fieldB := valB.Field(i)
+
+		if !fieldA.IsValid() || !fieldB.IsValid() {
+			return false
+		}
+		if !reflect.DeepEqual(fieldA.Interface(), fieldB.Interface()) {
+			return false
+		}
+	}
+	return true
+}