feat(lb): add backend datasource (#1784)

* feat(lb): add backend datasource

* typo

---------

Co-authored-by: Rémy Léone <[email protected]>

Author: yfodil

docs/data-sources/lb_backend.md

@@ -0,0 +1,55 @@
+---
+page_title: "Scaleway: scaleway_lb_backend"
+description: |-
+Manages Scaleway Load-Balancer Backends.
+---
+
+# scaleway_lb_backend
+
+Get information about Scaleway Load-Balancer Backends.
+For more information, see [the documentation](https://developers.scaleway.com/en/products/lb/zoned_api/#backends-cbf4eb).
+
+## Example Usage
+
+```hcl
+resource "scaleway_lb_ip" "main" {
+}
+
+resource "scaleway_lb" "main" {
+  ip_id = scaleway_lb_ip.main.id
+  name  = "data-test-lb-backend"
+  type  = "LB-S"
+}
+
+resource "scaleway_lb_backend" "main" {
+  lb_id            = scaleway_lb.main.id
+  name             = "backend01"
+  forward_protocol = "http"
+  forward_port     = "80"
+}
+
+data "scaleway_lb_backend" "byID" {
+  backend_id = scaleway_lb_backend.main.id
+}
+
+data "scaleway_lb_backend" "byName" {
+  name  = scaleway_lb_backend.main.name
+  lb_id = scaleway_lb.main.id
+}
+```
+
+## Arguments Reference
+
+The following arguments are supported:
+
+- `backend_id` - (Optional) The backend id.
+    - Only one of `name` and `backend_id` should be specified.
+
+- `name` - (Optional) The name of the backend.
+    - When using the `name` you should specify the `lb-id`
+
+- `lb_id` - (Required) The load-balancer ID this backend is attached to.
+
+## Attributes Reference
+
+See the [LB Backend Resource](../resources/lb_backend.md) for details on the returned attributes - they are identical.

scaleway/data_source_lb_backend.go

@@ -0,0 +1,66 @@
+package scaleway
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/hashicorp/terraform-plugin-sdk/v2/diag"
+	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema"
+	lbSDK "github.com/scaleway/scaleway-sdk-go/api/lb/v1"
+	"github.com/scaleway/scaleway-sdk-go/scw"
+)
+
+func dataSourceScalewayLbBackend() *schema.Resource {
+	// Generate datasource schema from resource
+	dsSchema := datasourceSchemaFromResourceSchema(resourceScalewayLbBackend().Schema)
+
+	// Set 'Optional' schema elements
+	addOptionalFieldsToSchema(dsSchema, "name", "lb_id")
+
+	dsSchema["name"].ConflictsWith = []string{"backend_id"}
+	dsSchema["backend_id"] = &schema.Schema{
+		Type:          schema.TypeString,
+		Optional:      true,
+		Description:   "The ID of the backend",
+		ValidateFunc:  validationUUIDorUUIDWithLocality(),
+		ConflictsWith: []string{"name"},
+	}
+
+	return &schema.Resource{
+		ReadContext: dataSourceScalewayLbBackendRead,
+		Schema:      dsSchema,
+	}
+}
+
+func dataSourceScalewayLbBackendRead(ctx context.Context, d *schema.ResourceData, meta interface{}) diag.Diagnostics {
+	api, zone, err := lbAPIWithZone(d, meta)
+	if err != nil {
+		return diag.FromErr(err)
+	}
+
+	backID, ok := d.GetOk("backend_id")
+	if !ok { // Get LB by name.
+		res, err := api.ListBackends(&lbSDK.ZonedAPIListBackendsRequest{
+			Zone: zone,
+			Name: expandStringPtr(d.Get("name")),
+			LBID: expandID(d.Get("lb_id")),
+		}, scw.WithContext(ctx))
+		if err != nil {
+			return diag.FromErr(err)
+		}
+		if len(res.Backends) == 0 {
+			return diag.FromErr(fmt.Errorf("no backends found with the name %s", d.Get("name")))
+		}
+		if len(res.Backends) > 1 {
+			return diag.FromErr(fmt.Errorf("%d backend found with the same name %s", len(res.Backends), d.Get("name")))
+		}
+		backID = res.Backends[0].ID
+	}
+	zonedID := datasourceNewZonedID(backID, zone)
+	d.SetId(zonedID)
+	err = d.Set("backend_id", zonedID)
+	if err != nil {
+		return diag.FromErr(err)
+	}
+	return resourceScalewayLbBackendRead(ctx, d, meta)
+}

scaleway/data_source_lb_backend_test.go

@@ -0,0 +1,55 @@
+package scaleway
+
+import (
+	"testing"
+
+	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/resource"
+)
+
+func TestAccScalewayDataSourceLbBackend_Basic(t *testing.T) {
+	tt := NewTestTools(t)
+	defer tt.Cleanup()
+	resource.ParallelTest(t, resource.TestCase{
+		PreCheck:          func() { testAccPreCheck(t) },
+		ProviderFactories: tt.ProviderFactories,
+		CheckDestroy:      testAccCheckScalewayLbIPDestroy(tt),
+		Steps: []resource.TestStep{
+			{
+				Config: `
+					resource scaleway_lb_ip main {
+					}
+
+					resource scaleway_lb main {
+					    ip_id = scaleway_lb_ip.main.id
+						name = "data-test-lb-backend"
+						type = "LB-S"
+					}
+
+					resource "scaleway_lb_backend" "main" {
+					  lb_id            = scaleway_lb.main.id
+					  name             = "backend01"
+					  forward_protocol = "http"
+					  forward_port     = "80"
+					}
+					
+					data "scaleway_lb_backend" "byID" {
+						backend_id = "${scaleway_lb_backend.main.id}"
+					}
+					
+					data "scaleway_lb_backend" "byName" {
+						name = "${scaleway_lb_backend.main.name}"
+						lb_id = "${scaleway_lb.main.id}"
+					}
+				`,
+				Check: resource.ComposeTestCheckFunc(
+					resource.TestCheckResourceAttrPair(
+						"data.scaleway_lb_backend.byID", "name",
+						"scaleway_lb_backend.main", "name"),
+					resource.TestCheckResourceAttrPair(
+						"data.scaleway_lb_backend.byName", "id",
+						"scaleway_lb_backend.main", "id"),
+				),
+			},
+		},
+	})
+}

scaleway/provider.go

@@ -192,6 +192,7 @@ func Provider(config *ProviderConfig) plugin.ProviderFunc {
 				"scaleway_k8s_pool":                            dataSourceScalewayK8SPool(),
 				"scaleway_k8s_version":                         dataSourceScalewayK8SVersion(),
 				"scaleway_lb":                                  dataSourceScalewayLb(),
+				"scaleway_lb_backend":                          dataSourceScalewayLbBackend(),
 				"scaleway_lb_certificate":                      dataSourceScalewayLbCertificate(),
 				"scaleway_lb_frontend":                         dataSourceScalewayLbFrontend(),
 				"scaleway_lb_ip":                               dataSourceScalewayLbIP(),