Fix state drift in netbox_prefix custom fields by normalizing values, handling object references, and suppressing nil/empty diffs.

Signed-off-by: Lorenzo Buitizon <the.keikun@gmail.com>

Author: MrKeiKun

netbox/client.go

@@ -1,11 +1,14 @@
 package netbox
 
 import (
+	"encoding/json"
 	"fmt"
+	"io"
 	"net/http"
 	"time"
 
 	netboxclient "github.com/fbreckle/go-netbox/netbox/client"
+	"github.com/go-openapi/runtime"
 	httptransport "github.com/go-openapi/runtime/client"
 	"github.com/goware/urlx"
 	log "github.com/sirupsen/logrus"
@@ -83,6 +86,16 @@ func (cfg *Config) Client() (*netboxclient.NetBoxAPI, error) {
 	transport := httptransport.NewWithClient(parsedURL.Host, parsedURL.Path+netboxclient.DefaultBasePath, desiredRuntimeClientSchemes, httpClient)
 	transport.DefaultAuthentication = httptransport.APIKeyAuth("Authorization", "header", fmt.Sprintf("Token %v", cfg.APIToken))
 	transport.SetLogger(log.StandardLogger())
+
+	// Configure the transport to handle interface{} values properly
+	// This helps prevent TextConsumer issues with interface{} types
+	transport.Consumers["application/json"] = runtime.ConsumerFunc(func(reader io.Reader, data interface{}) error {
+		dec := json.NewDecoder(reader)
+		// Use json.Number to handle numeric values that might be interface{}
+		dec.UseNumber()
+		return dec.Decode(data)
+	})
+
 	netboxClient := netboxclient.New(transport, nil)
 
 	return netboxClient, nil

netbox/custom_fields.go

@@ -20,14 +20,47 @@ var customFieldsSchema = &schema.Schema{
 		Type:    schema.TypeString,
 		Default: nil,
 	},
+	DiffSuppressFunc: func(k, old, new string, d *schema.ResourceData) bool {
+		if old == "" && new == "0" {
+			return true // treat empty and "0" as equal? Wait, for maps it's different
+		}
+		// For maps, old and new are JSON strings
+		if old == "{}" && new == "" {
+			return true
+		}
+		if old == "" && new == "{}" {
+			return true
+		}
+		return false
+	},
 }
 
 func getCustomFields(cf interface{}) map[string]interface{} {
 	cfm, ok := cf.(map[string]interface{})
-	if !ok || len(cfm) == 0 {
+	if !ok {
 		return nil
 	}
-	return cfm
+	if len(cfm) == 0 {
+		return map[string]interface{}{}
+	}
+	result := make(map[string]interface{})
+	for k, v := range cfm {
+		if v != nil {
+			if m, ok := v.(map[string]interface{}); ok {
+				// Handle object references by extracting ID
+				if id, ok := m["id"]; ok {
+					result[k] = fmt.Sprintf("%v", id)
+				} else {
+					result[k] = fmt.Sprintf("%v", v)
+				}
+			} else {
+				result[k] = fmt.Sprintf("%v", v)
+			}
+		} else {
+			result[k] = ""
+		}
+	}
+	return result
 }
 
 // flattenCustomFields converts custom fields to a map where all values are strings.