Fixing errors and adding doc template

docs/resources/custom_device.md

@@ -0,0 +1,38 @@
+---
+layout: ""
+page_title: dynatrace_custom_device Resource - terraform-provider-dynatrace"
+description: |-
+  The resource `dynatrace_custom_device` covers configuration for custom devices
+---
+
+# dynatrace_custom_device (Resource)
+
+## Dynatrace Documentation
+
+- Monitored entities API - https://www.dynatrace.com/support/help/dynatrace-api/environment-api/entity-v2 
+
+
+## Resource Example Usage
+
+```terraform
+resource "dynatrace_custom_device" "#name#" {
+  custom_device_id = "customDeviceId"
+  display_name     = "customDevicename"
+}
+```
+<!-- schema generated by tfplugindocs -->
+## Schema
+
+### Required
+
+- `display_name` (String) Tag name
+
+### Optional
+
+- `custom_device_id` (String) This Id can either be provided in the resource or generated by Terraform when the resource is created. If you use the ID of an existing device, the respective parameters will be updated.
+
+### Read-Only
+
+- `id` (String) The ID of this resource - same value as the `custom_device_id`.
+- `entity_id` (String) The Dynatrace EntityId of this resource.
+

dynatrace/api/v2/customdevice/service.go

@@ -19,6 +19,8 @@ package customdevice
 
 import (
 	"fmt"
+	"sync"
+	"time"
 
 	"github.com/dynatrace-oss/terraform-provider-dynatrace/dynatrace/api"
 	customdevice "github.com/dynatrace-oss/terraform-provider-dynatrace/dynatrace/api/v2/customdevice/settings"
@@ -27,6 +29,8 @@ import (
 	"github.com/google/uuid"
 )
 
+var mutex = &sync.Mutex{}
+
 func Service(credentials *settings.Credentials) settings.CRUDService[*customdevice.CustomDevice] {
 	return &service{credentials}
 }
@@ -37,26 +41,53 @@ type service struct {
 
 func (me *service) Get(id string, v *customdevice.CustomDevice) error {
 	var err error
-
 	client := rest.DefaultClient(me.credentials.URL, me.credentials.Token)
 	entitySelector := `detectedName("` + id + `"),type("CUSTOM_DEVICE")`
-	req := client.Get(fmt.Sprintf("/api/v2/entities?from=now-3y&&entitySelector=%s", entitySelector)).Expect(200)
-	var enitityList customdevice.CustomDeviceList
-	if err = req.Finish(enitityList); err != nil {
-		return err
+	var CustomDeviceGetResponse customdevice.CustomDeviceGetResponse
+
+	// The result from the GET API enpoint is not very stable, so attepting to get the custom device once is not enough.
+	// 20 is an arbitraty number (it takes 40s before the method gives up) that should be long enough for the endpoint to return a value.
+	for i := 0; i < 20; i++ {
+		req := client.Get(fmt.Sprintf("/api/v2/entities?from=now-3y&&entitySelector=%s", entitySelector)).Expect(200)
+		err = req.Finish(&CustomDeviceGetResponse)
+		if len(CustomDeviceGetResponse.Entities) != 0 {
+			break
+		}
+		time.Sleep(2 * time.Second)
 	}
 
-	if len(enitityList.Entities) == 0 {
+	if len(CustomDeviceGetResponse.Entities) == 0 {
+		// We only throu this error if the Finish method failed for the last attempt because sometimes random calls fail.
+		// This way if all calls fail, the last will fail as well, and we only get a false positive if the last call happens to be the only one to fail.
+		if err != nil {
+			return err
+		}
 		return rest.Error{Code: 404, Message: `Custom device with ID:` + id + " not found!"}
 	}
 
-	v.DisplayName = enitityList.Entities[0].DisplayName
-	v.EntityId = enitityList.Entities[0].EntityId
+	v.DisplayName = CustomDeviceGetResponse.Entities[0].DisplayName
+	v.EntityId = CustomDeviceGetResponse.Entities[0].EntityId
 	v.CustomDeviceID = id
 
 	return nil
 }
 
+func (me *service) CheckGet(id string, v *customdevice.CustomDevice) error {
+	var err error
+	client := rest.DefaultClient(me.credentials.URL, me.credentials.Token)
+	entitySelector := `detectedName("` + id + `"),type("CUSTOM_DEVICE")`
+	req := client.Get(fmt.Sprintf("/api/v2/entities?from=now-3y&&entitySelector=%s", entitySelector)).Expect(200)
+	var CustomDeviceGetResponse customdevice.CustomDeviceGetResponse
+	if err = req.Finish(&CustomDeviceGetResponse); err != nil {
+		return err
+	}
+	if len(CustomDeviceGetResponse.Entities) == 0 {
+		return nil
+	}
+	v.EntityId = CustomDeviceGetResponse.Entities[0].EntityId
+	return nil
+}
+
 func (me *service) SchemaID() string {
 	return "v2:environment:custom-device"
 }
@@ -70,28 +101,34 @@ func (me *service) Validate(v *customdevice.CustomDevice) error {
 }
 
 func (me *service) Create(v *customdevice.CustomDevice) (*api.Stub, error) {
+	mutex.Lock()
+	defer mutex.Unlock()
 	var err error
 	if v.CustomDeviceID == "" {
 		v.CustomDeviceID = uuid.NewString()
 	}
-	resultDevice := customdevice.CustomDevice{}
 	client := rest.DefaultClient(me.credentials.URL, me.credentials.Token)
-	if err = client.Post("/api/v2/entities/custom", v, 201, 204).Finish(&resultDevice); err != nil {
+	if err = client.Post("/api/v2/entities/custom", v, 201, 204).Finish(); err != nil {
 		return nil, err
 	}
-	resultDevice.CustomDeviceID = v.CustomDeviceID
-	resultDevice.DisplayName = v.DisplayName
 
-	return &api.Stub{ID: resultDevice.CustomDeviceID, Name: *resultDevice.DisplayName, Value: resultDevice}, nil
+	// Check the custom device was indeed created before finishing up
+	for i := 0; i < 50; i++ {
+		me.CheckGet(v.CustomDeviceID, v)
+		time.Sleep(2 * time.Second)
+		if v.EntityId != "" {
+			break
+		}
+	}
+	return &api.Stub{ID: v.CustomDeviceID, Name: *v.DisplayName}, nil
 }
 
 func (me *service) Update(id string, v *customdevice.CustomDevice) error {
 	var err error
 	v.CustomDeviceID = id
-	v.EntityId = nil
-	resultDevice := customdevice.CustomDevice{}
+	v.EntityId = ""
 	client := rest.DefaultClient(me.credentials.URL, me.credentials.Token)
-	if err = client.Post("/api/v2/entities/custom", v, 201, 204).Finish(&resultDevice); err != nil {
+	if err = client.Post("/api/v2/entities/custom", v, 204).Finish(); err != nil {
 		return err
 	}
 	return nil

dynatrace/api/v2/customdevice/settings/custom_device.go

@@ -6,16 +6,13 @@ import (
 )
 
 type CustomDevice struct {
-	EntityId *string `json:"entityId,omitempty"` // The ID of the custom device.
-	// Type        *string        `json:"type,omitempty"`        // The type of the custom device.
-	DisplayName *string `json:"displayName,omitempty"` // The name of the custom device, displayed in the UI.
-	// Tags        Tags           `json:"tags,omitempty"`        // A set of tags assigned to the custom device.
-	// Properties  map[string]any `json:"properties"`
-	CustomDeviceID string `json:"customDeviceId,omitempty"`
+	EntityId       string  `json:"entityId,omitempty"`       // The ID of the custom device.
+	DisplayName    *string `json:"displayName,omitempty"`    // The name of the custom device, displayed in the UI.
+	CustomDeviceID string  `json:"customDeviceId,omitempty"` // A unique name that can be provided or generated by the provider
 }
 
-type CustomDeviceList struct {
-	Entities []*CustomDevice `json:"entities"` // An unordered list of custom devices
+type CustomDeviceGetResponse struct {
+	Entities []*CustomDevice `json:"entities,omitempty"` // An unordered list of custom devices
 }
 
 func (me *CustomDevice) Schema() map[string]*schema.Schema {
@@ -35,10 +32,37 @@ func (me *CustomDevice) Schema() map[string]*schema.Schema {
 			Description: "The unique name of the custom device.",
 			Optional:    true,
 			Computed:    true,
+			ForceNew:    true,
 		},
 	}
 }
 
+func (me *CustomDeviceGetResponse) Schema() map[string]*schema.Schema {
+	return map[string]*schema.Schema{
+		"entities": {
+			Type:        schema.TypeString,
+			Description: "The list of entities returned by the GET call.",
+			Optional:    true,
+			Computed:    true,
+		},
+	}
+}
+
+func (me *CustomDeviceGetResponse) MarshalHCL(properties hcl.Properties) error {
+	if err := properties.EncodeAll(map[string]any{
+		"entities": me.Entities,
+	}); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (me *CustomDeviceGetResponse) UnmarshalHCL(decoder hcl.Decoder) error {
+	return decoder.DecodeAll(map[string]any{
+		"entities": &me.Entities,
+	})
+}
+
 func (me *CustomDevice) MarshalHCL(properties hcl.Properties) error {
 	if err := properties.EncodeAll(map[string]any{
 		"entity_id":        me.EntityId,

terraform.tfstate

@@ -0,0 +1,8 @@
+{
+  "version": 4,
+  "terraform_version": "1.2.9",
+  "serial": 1,
+  "lineage": "2e9ffda4-8331-7a07-571a-1e66b1588f69",
+  "outputs": {},
+  "resources": []
+}