azurerm_log_analytics_workspace: allow changing sku between CapacityReservation and PerGB2018

internal/services/loganalytics/log_analytics_workspace_resource.go

@@ -117,7 +117,6 @@ func resourceLogAnalyticsWorkspace() *pluginsdk.Resource {
 			"reservation_capacity_in_gb_per_day": {
 				Type:     pluginsdk.TypeInt,
 				Optional: true,
-				Computed: true,
 				ValidateFunc: validation.IntInSlice([]int{
 					int(workspaces.CapacityReservationLevelOneHundred),
 					int(workspaces.CapacityReservationLevelTwoHundred),
@@ -178,7 +177,12 @@ func resourceLogAnalyticsWorkspaceCustomDiff(ctx context.Context, d *pluginsdk.R
 		log.Printf("[INFO] Log Analytics Workspace SKU: OLD: %q, NEW: %q", old, new)
 		// If the old value is not LACluster(e.g. "") return ForceNew because they are
 		// really changing the sku...
-		if !strings.EqualFold(old.(string), string(workspaces.WorkspaceSkuNameEnumLACluster)) && !strings.EqualFold(old.(string), "") {
+		changingFromLACluster := strings.EqualFold(old.(string), string(workspaces.WorkspaceSkuNameEnumLACluster)) || strings.EqualFold(old.(string), "")
+		// changing from capacity reservation to perGB does not force new when the last sku update date is more than 31-days ago.
+		// to let users do the change, we do not force new in this case and let the API error out.
+		changingFromCapacityReservationToPerGB := strings.EqualFold(old.(string), string(workspaces.WorkspaceSkuNameEnumCapacityReservation)) && strings.EqualFold(new.(string), string(workspaces.WorkspaceSkuNameEnumPerGBTwoZeroOneEight))
+		changingFromPerGBToCapacityReservation := strings.EqualFold(old.(string), string(workspaces.WorkspaceSkuNameEnumPerGBTwoZeroOneEight)) && strings.EqualFold(new.(string), string(workspaces.WorkspaceSkuNameEnumCapacityReservation))
+		if !changingFromCapacityReservationToPerGB && !changingFromLACluster && !changingFromPerGBToCapacityReservation {
 			d.ForceNew("sku")
 		}
 	}

internal/services/loganalytics/log_analytics_workspace_resource_test.go

@@ -331,6 +331,29 @@ func TestAccLogAnalyticsWorkspace_ToggleDisableLocalAuth(t *testing.T) {
 	})
 }
 
+func TestAccLogAnalyticsWorkspace_updateSku(t *testing.T) {
+	data := acceptance.BuildTestData(t, "azurerm_log_analytics_workspace", "test")
+	r := LogAnalyticsWorkspaceResource{}
+
+	data.ResourceTest(t, r, []acceptance.TestStep{
+		{
+			Config: r.basic(data),
+			Check: acceptance.ComposeTestCheckFunc(
+				check.That(data.ResourceName).ExistsInAzure(r),
+			),
+		},
+		data.ImportStep(),
+		{
+			Config: r.withCapacityReservationTypo(data, 100),
+			Check: acceptance.ComposeTestCheckFunc(
+				check.That(data.ResourceName).ExistsInAzure(r),
+				check.That(data.ResourceName).Key("reservation_capacity_in_gb_per_day").HasValue("100"),
+			),
+		},
+		data.ImportStep(),
+	})
+}
+
 func (t LogAnalyticsWorkspaceResource) Exists(ctx context.Context, clients *clients.Client, state *pluginsdk.InstanceState) (*bool, error) {
 	id, err := workspaces.ParseWorkspaceID(state.ID)
 	if err != nil {

website/docs/r/log_analytics_workspace.html.markdown

@@ -45,6 +45,8 @@ The following arguments are supported:
 
 ~> **NOTE:** A new pricing model took effect on `2018-04-03`, which requires the SKU `PerGB2018`. If you're provisioned resources before this date you have the option of remaining with the previous Pricing SKU and using the other SKUs defined above. More information about [the Pricing SKUs is available at the following URI](https://aka.ms/PricingTierWarning).
 
+~> **NOTE:** Changing `sku` forces a new Log Analytics Workspace to be created, except when changing between `PerGB2018` and `CapacityReservation`. However, changing `sku` to `CapacityReservation` or changing `reservation_capacity_in_gb_per_day` to a higher tier will lead to a 31-days commitment period, during which the SKU cannot be changed to a lower one. Please refer to [official documentation](https://learn.microsoft.com/en-us/azure/azure-monitor/logs/cost-logs#commitment-tiers) for further information.
+
 ~> **NOTE:** The `Free` SKU has a default `daily_quota_gb` value of `0.5` (GB).
 
 * `retention_in_days` - (Optional) The workspace data retention in days. Possible values are either 7 (Free Tier only) or range between 30 and 730.
@@ -59,7 +61,7 @@ The following arguments are supported:
 
 * `internet_query_enabled` - (Optional) Should the Log Analytics Workspace support querying over the Public Internet? Defaults to `true`.
 
-* `reservation_capacity_in_gb_per_day` - (Optional) The capacity reservation level in GB for this workspace. Must be in increments of 100 between 100 and 5000.
+* `reservation_capacity_in_gb_per_day` - (Optional) The capacity reservation level in GB for this workspace. Possible values are `100`, `200`, `300`, `400`, `500`, `1000`, `2000` and `5000`.
 
 ~> **NOTE:** `reservation_capacity_in_gb_per_day` can only be used when the `sku` is set to `CapacityReservation`.