fix(azure): read Cosmos DB, SQL and Synapse held reservations from the Reservations API

CHANGELOG.md

@@ -309,6 +309,12 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/).
 
 - **Breaking (source):** `managedredis.ReservationsDetailsPager` and `(*managedredis.Client).SetReservationsPager` are removed; tests inject reservation inventory with `SetInventoryFactories` instead (#699).
 - **`azure` Redis:** `managedredis.GetExistingCommitments` now reads held reservations from the Reservations API (purchase date, quantity, location, state), so a Redis reservation bought in the last day reduces the matching recommendation instead of being invisible to the duplicate guard (#699). An incomplete live reservation row (missing SKU, location, quantity or purchase date, an unattributable scope, or an expiry falling today) now fails the lookup with an error instead of being skipped, as `azure` compute already does.
+- **Breaking (source):** `cosmosdb.ReservationsDetailsPager` and `(*cosmosdb.Client).SetReservationsPager` are removed; tests inject reservation inventory with `SetInventoryFactories` instead (#705).
+- **`azure` Cosmos DB:** `cosmosdb.GetExistingCommitments` now reads held reservations from the Reservations API (purchase date, quantity, location, state), so a Cosmos DB reservation bought in the last day reduces the matching recommendation instead of being invisible to the duplicate guard. `Region` is now the reservation location, not the client region. An incomplete live reservation row fails the lookup with an error instead of being skipped (#705).
+- **Breaking (source):** `synapse.ReservationsDetailsPager` and `(*synapse.Client).SetReservationsPager` are removed; tests inject reservation inventory with `SetInventoryFactories` instead (#705).
+- **`azure` Synapse:** `synapse.GetExistingCommitments` now reads held reservations from the Reservations API (purchase date, quantity, location, state), so a Synapse reservation bought in the last day reduces the matching recommendation instead of being invisible to the duplicate guard. `Region` is now the reservation location, not the client region. An incomplete live reservation row fails the lookup with an error instead of being skipped (#705).
+- **Breaking (source):** `database.ReservationsDetailsPager` and `(*database.Client).SetReservationsPager` are removed; tests inject reservation inventory with `SetInventoryFactories` instead (#705).
+- **`azure` SQL Database:** `database.GetExistingCommitments` now reads held reservations from the Reservations API (purchase date, quantity, location, state), so a SQL Database reservation bought in the last day reduces the matching recommendation instead of being invisible to the duplicate guard. Held reservations carry engine `sqlserver` and the subscription's dominant zone-redundancy setting, as recommendations do. `Region` is now the reservation location, not the client region. An incomplete live reservation row fails the lookup with an error instead of being skipped (#705).
 - **`aws` RI recommendations:** a fractional Cost Explorer quantity now rounds
   down instead of to the nearest integer, so a purchase never exceeds CE's
   quantity. The upfront, recurring monthly cost, monthly savings and savings

pkg/common/types.go

@@ -527,12 +527,12 @@ const (
 
 // Commitment represents an existing commitment (RI/SP/CUD/etc).
 //
-// Deployment is RDS-specific (Multi-AZ vs Single-AZ); it stays empty for
-// services that don't have a deployment dimension (EC2, ElastiCache,
-// etc). When populated, it carries the same vocabulary as
-// DatabaseDetails.AZConfig on Recommendation ("single-az" / "multi-az")
-// so pool-key matching can collapse both sides via normaliseDeployment
-// in the recommendations package. Without this field, RDS expiry
+// Deployment is set for AWS RDS and Azure SQL Database and stays empty for
+// services without a deployment dimension (EC2, ElastiCache, etc). When
+// populated, it carries the same vocabulary as DatabaseDetails.AZConfig on
+// Recommendation ("single-az" / "multi-az" on AWS, "zoneRedundant" / "none"
+// on Azure) so pool-key matching can collapse both sides via
+// normaliseDeployment in the recommendations package. Without this field, RDS expiry
 // adjustments would silently miss because Recommendation lookup keys
 // are deployment-aware while commitment keys defaulted to empty.
 type Commitment struct {
@@ -546,7 +546,7 @@ type Commitment struct {
 	Region         string          `json:"region"`
 	ResourceType   string          `json:"resource_type"`
 	Engine         string          `json:"engine,omitempty"`     // Database engine for RDS/ElastiCache (e.g., "mysql", "aurora-postgresql")
-	Deployment     string          `json:"deployment,omitempty"` // RDS Multi-AZ vs Single-AZ; empty for non-RDS
+	Deployment     string          `json:"deployment,omitempty"` // RDS Multi-AZ vs Single-AZ, Azure SQL zone redundancy; empty otherwise
 	State          CommitmentState `json:"state"`
 
 	// EC2 reserved-instance dimensions. Empty means unknown or a wildcard.

providers/azure/provider_test.go

@@ -13,6 +13,7 @@ import (
 	"github.com/Azure/azure-sdk-for-go/sdk/azcore/cloud"
 	"github.com/Azure/azure-sdk-for-go/sdk/azcore/policy"
 	"github.com/Azure/azure-sdk-for-go/sdk/resourcemanager/consumption/armconsumption"
+	"github.com/Azure/azure-sdk-for-go/sdk/resourcemanager/reservations/armreservations"
 	"github.com/Azure/azure-sdk-for-go/sdk/resourcemanager/resources/armsubscriptions"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -469,8 +470,6 @@ func TestAzureClients_GetExistingCommitments_PagerConstructionError(t *testing.T
 		client provider.ServiceClient
 	}{
 		{"cache", NewCacheClient(nil, "test-subscription", "eastus")},
-		{"cosmosdb", NewCosmosDBClient(nil, "test-subscription", "eastus")},
-		{"database", NewDatabaseClient(nil, "test-subscription", "eastus")},
 		{"search", NewSearchClient(nil, "test-subscription", "eastus")},
 	} {
 		t.Run(tc.name, func(t *testing.T) {
@@ -485,6 +484,36 @@ func TestAzureClients_GetExistingCommitments_PagerConstructionError(t *testing.T
 	}
 }
 
+// Held reservations come from the Reservations API, so a client-construction
+// failure of the default inventory factories surfaces under the shared
+// "<service>: list applied reservations" prefix.
+func TestAzureClients_ReservationInventory_DefaultFactoryError(t *testing.T) {
+	// Keep this test sequential: the SDK reads this process-wide configuration.
+	originalCloud := cloud.AzurePublic
+	t.Cleanup(func() { cloud.AzurePublic = originalCloud })
+	cloud.AzurePublic = cloud.Configuration{}
+
+	_, sdkErr := armreservations.NewAzureReservationAPIClient(nil, nil)
+	require.Error(t, sdkErr)
+
+	for _, tc := range []struct {
+		name   string
+		client provider.ServiceClient
+	}{
+		{"cosmosdb", NewCosmosDBClient(nil, "test-subscription", "eastus")},
+		{"database", NewDatabaseClient(nil, "test-subscription", "eastus")},
+		{"synapse", NewSynapseClient(nil, "test-subscription", "eastus")},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			commitments, err := tc.client.GetExistingCommitments(context.Background())
+			require.Error(t, err)
+			assert.Nil(t, commitments)
+			assert.Contains(t, err.Error(), tc.name+": list applied reservations: ")
+			assert.Contains(t, err.Error(), sdkErr.Error())
+		})
+	}
+}
+
 func TestAzureProvider_GetRecommendationsClient_NotConfigured(t *testing.T) {
 	t.Parallel()
 	// Test GetRecommendationsClient when Azure is not configured. Inject a

providers/azure/services/compute/client.go

@@ -294,24 +294,8 @@ func (c *Client) GetExistingCommitments(ctx context.Context) ([]common.Commitmen
 		factories = *c.inventoryFactories
 	}
 
-	responses, err := reservations.ListAppliedReservations(ctx, c.subscriptionID, factories, maxReservationsPages)
-	if err != nil {
-		return nil, fmt.Errorf("compute: list applied reservations: %w", err)
-	}
-
-	now := time.Now()
-	commitments := make([]common.Commitment, 0, len(responses))
-	for _, r := range responses {
-		commitment, err := reservations.StrictCommitment(r, c.subscriptionID, common.ServiceCompute,
-			armreservations.ReservedResourceTypeVirtualMachines, reservations.StrictLabels{Service: "compute", Resource: "VM"}, now)
-		if err != nil {
-			return nil, err
-		}
-		if commitment != nil {
-			commitments = append(commitments, *commitment)
-		}
-	}
-	return commitments, nil
+	return reservations.StrictCommitments(ctx, c.subscriptionID, factories, maxReservationsPages, common.ServiceCompute,
+		armreservations.ReservedResourceTypeVirtualMachines, reservations.StrictLabels{Service: "compute", Resource: "VM"})
 }
 
 // providerRegistrationState is the JSON shape returned by the ARM providers API.

providers/azure/services/cosmosdb/client.go

@@ -53,12 +53,6 @@ type RecommendationsPager interface {
 	NextPage(ctx context.Context) (armconsumption.ReservationRecommendationsClientListResponse, error)
 }
 
-// ReservationsDetailsPager interface for reservations details pager (enables mocking).
-type ReservationsDetailsPager interface {
-	More() bool
-	NextPage(ctx context.Context) (armconsumption.ReservationsDetailsClientListResponse, error)
-}
-
 // CosmosAccountsPager interface for Cosmos DB accounts pager (enables mocking).
 type CosmosAccountsPager interface {
 	More() bool
@@ -70,7 +64,7 @@ type Client struct {
 	cred                 azcore.TokenCredential
 	httpClient           HTTPClient
 	recommendationsPager RecommendationsPager
-	reservationsPager    ReservationsDetailsPager
+	inventoryFactories   *reservations.InventoryFactories
 	cosmosAccountsPager  CosmosAccountsPager
 	subscriptionID       string
 	region               string
@@ -118,9 +112,18 @@ func (c *Client) SetRecommendationsPager(pager RecommendationsPager) {
 	c.recommendationsPager = pager
 }
 
-// SetReservationsPager sets the reservations pager (for testing).
-func (c *Client) SetReservationsPager(pager ReservationsDetailsPager) {
-	c.reservationsPager = pager
+// SetInventoryFactories injects reservation-inventory factories (for testing).
+func (c *Client) SetInventoryFactories(f *reservations.InventoryFactories) {
+	c.inventoryFactories = f
+}
+
+// factories returns the injected inventory factories, or the real SDK-backed
+// ones when none were injected (production only calls NewClient).
+func (c *Client) factories() reservations.InventoryFactories {
+	if c.inventoryFactories != nil {
+		return *c.inventoryFactories
+	}
+	return reservations.DefaultInventoryFactories(c.cred)
 }
 
 // SetCosmosAccountsPager sets the Cosmos DB accounts pager (for testing).
@@ -212,91 +215,14 @@ func (c *Client) appendPage(ctx context.Context, pricer *azrecs.Pricer, recs []c
 	return recs, nil
 }
 
-// GetExistingCommitments retrieves existing Cosmos DB reserved capacity using Azure Resource Graph.
+// GetExistingCommitments retrieves the Cosmos DB reservations that apply to
+// this subscription from the Reservations API, which carries the purchase
+// date, quantity, location and lifecycle state the duplicate-purchase guard
+// needs (issue #705). Any failure or incomplete live row is returned as an
+// error rather than as an empty or partial inventory.
 func (c *Client) GetExistingCommitments(ctx context.Context) ([]common.Commitment, error) {
-	pager, err := c.createReservationsPager()
-	if err != nil {
-		return nil, fmt.Errorf("cosmosdb: create reservations pager: %w", err)
-	}
-
-	return c.collectCosmosReservations(ctx, pager)
-}
-
-// createReservationsPager creates a pager for listing reservations.
-func (c *Client) createReservationsPager() (ReservationsDetailsPager, error) {
-	// Use injected pager if available (for testing)
-	if c.reservationsPager != nil {
-		return c.reservationsPager, nil
-	}
-
-	client, err := armconsumption.NewReservationsDetailsClient(c.cred, nil)
-	if err != nil {
-		return nil, err
-	}
-
-	scope := fmt.Sprintf("subscriptions/%s", c.subscriptionID)
-	return client.NewListPager(scope, &armconsumption.ReservationsDetailsClientListOptions{}), nil
-}
-
-// collectCosmosReservations collects Cosmos DB reservations from the pager.
-// Returns an error on first pagination failure so callers can't silently act
-// on a partial list — see the compute client for the full rationale.
-func (c *Client) collectCosmosReservations(ctx context.Context, pager ReservationsDetailsPager) ([]common.Commitment, error) {
-	commitments := make([]common.Commitment, 0)
-
-	for pageIdx := 0; pager.More(); pageIdx++ {
-		if err := ctx.Err(); err != nil {
-			return nil, fmt.Errorf("context canceled during pagination: %w", err)
-		}
-		if pageIdx >= maxReservationsPages {
-			return nil, fmt.Errorf("cosmosdb: GetExistingCommitments pagination cap (%d pages) reached", maxReservationsPages)
-		}
-		page, err := slot.NextPage(ctx, pager)
-		if err != nil {
-			return nil, fmt.Errorf("cosmosdb: list reservations: %w", err)
-		}
-
-		for _, detail := range page.Value {
-			if commitment := c.convertCosmosReservation(detail); commitment != nil {
-				commitments = append(commitments, *commitment)
-			}
-		}
-	}
-
-	// ReservationsDetails is a daily usage API: one row per reservation per
-	// usage day. Without this, a single reservation held for N days would
-	// surface as N commitments sharing one CommitmentID (issue #73).
-	return reservations.DedupeCommitmentsByID(commitments), nil
-}
-
-// convertCosmosReservation converts a reservation detail to a commitment if it's a Cosmos DB reservation.
-func (c *Client) convertCosmosReservation(detail *armconsumption.ReservationDetail) *common.Commitment {
-	if detail.Properties == nil {
-		return nil
-	}
-
-	props := detail.Properties
-	if props.SKUName == nil || !strings.Contains(strings.ToLower(*props.SKUName), "cosmos") {
-		return nil
-	}
-
-	commitment := &common.Commitment{
-		Provider:       common.ProviderAzure,
-		Account:        c.subscriptionID,
-		CommitmentType: common.CommitmentReservedInstance,
-		Service:        common.ServiceNoSQL,
-		Region:         c.region,
-		State:          common.CommitmentStateActive,
-	}
-
-	if props.ReservationID != nil {
-		commitment.CommitmentID = *props.ReservationID
-	}
-	if props.SKUName != nil {
-		commitment.ResourceType = *props.SKUName
-	}
-
-	return commitment
+	return reservations.StrictCommitments(ctx, c.subscriptionID, c.factories(), maxReservationsPages, common.ServiceNoSQL,
+		armreservations.ReservedResourceTypeCosmosDb, reservations.StrictLabels{Service: "cosmosdb", Resource: "Cosmos DB"})
 }
 
 // PurchaseCommitment purchases Cosmos DB reserved capacity using the two-step