Adding the support to override the defaul the observability api url with client side of changes

synthetics/provider.go

@@ -17,6 +17,7 @@ package synthetics
 import (
 	"context"
 	"regexp"
+	"strings"
 
 	sc2 "github.com/splunk/syntheticsclient/v2/syntheticsclientv2"
 
@@ -48,6 +49,12 @@ func Provider() *schema.Provider {
 				Description: "Splunk Observability Realm (E.G. `us1`). Will pull from `REALM` environment variable if available. For Rigor use realm rigor",
 				DefaultFunc: schema.EnvDefaultFunc("REALM", nil),
 			},
+			"apiurl": {
+			    Type:     schema.TypeString,
+			    Optional: true,
+			    Description: "Splunk Observability Realm API Endpoint (E.G. `https://api.<REALM>.signalfx.com`). Will pull from `API_URL` environment variable if available.",
+			    DefaultFunc: schema.EnvDefaultFunc("API_URL", nil),
+			},
 		},
 		ResourcesMap: map[string]*schema.Resource{
 			"synthetics_create_http_check":                resourceHttpCheck(),
@@ -82,28 +89,34 @@ func providerConfigure(ctx context.Context, d *schema.ResourceData) (interface{}
 	token := d.Get("apikey").(string)
 	realm := d.Get("realm").(string)
 	product := d.Get("product").(string)
+	apiurl := d.Get("apiurl").(string)
 
 	var diags diag.Diagnostics
 
 	if product == "observability" {
 		if token != "" && realm != "" {
-			c := sc2.NewClient(token, realm)
+			if apiurl != "" {
+				args := sc2.NewClientArgs(
+					30,
+					strings.TrimSuffix(apiurl, "/")+"/v2/synthetics",
+				)
+				c := sc2.NewConfigurableClient(token, realm, args)
+				return c, diags
+			}
 
+			// Default client (no apiurl override)
+			c := sc2.NewClient(token, realm)
 			return c, diags
 		}
 
 		c := sc2.NewClient(token, realm)
-
 		return c, diags
 	} else {
 		if product == "rigor" && token != "" {
 			c := sc.NewClient(token)
-
 			return c, diags
 		}
-
 		c := sc.NewClient(token)
-
 		return c, diags
 	}
 }