feat(platform-api): support upstreamDefinitions pool and per-operation upstream overrides

platform-api/internal/dto/api.go

@@ -137,15 +137,16 @@ type Vhosts struct {
 
 // APIYAMLData represents a basic spec section of the API deployment YAML
 type APIYAMLData struct {
-	DisplayName       string                 `yaml:"displayName"`
-	Version           string                 `yaml:"version"`
-	Context           string                 `yaml:"context"`
-	SubscriptionPlans []string               `yaml:"subscriptionPlans,omitempty"`
-	Vhosts            *Vhosts                `yaml:"vhosts,omitempty"`
-	Upstream          *UpstreamYAML          `yaml:"upstream,omitempty"`
-	Policies          []Policy               `yaml:"policies,omitempty"`
-	Operations        []api.OperationRequest `yaml:"operations,omitempty"`
-	Channels          []api.ChannelRequest   `yaml:"channels,omitempty"`
+	DisplayName         string                 `yaml:"displayName"`
+	Version             string                 `yaml:"version"`
+	Context             string                 `yaml:"context"`
+	SubscriptionPlans   []string               `yaml:"subscriptionPlans,omitempty"`
+	Vhosts              *Vhosts                `yaml:"vhosts,omitempty"`
+	Upstream            *UpstreamYAML          `yaml:"upstream,omitempty"`
+	UpstreamDefinitions []ReusableUpstreamYAML `yaml:"upstreamDefinitions,omitempty"`
+	Policies            []Policy               `yaml:"policies,omitempty"`
+	Operations          []api.OperationRequest `yaml:"operations,omitempty"`
+	Channels            []api.ChannelRequest   `yaml:"channels,omitempty"`
 }
 
 // UpstreamYAML represents the upstream configuration for API deployment YAML
@@ -160,10 +161,28 @@ type UpstreamTarget struct {
 	Ref string `yaml:"ref,omitempty"`
 }
 
+// ReusableUpstreamYAML represents a named entry in the deployment YAML's upstreamDefinitions pool.
+type ReusableUpstreamYAML struct {
+	Name      string                `yaml:"name"`
+	BasePath  string                `yaml:"basePath,omitempty"`
+	Timeout   *UpstreamTimeoutYAML  `yaml:"timeout,omitempty"`
+	Upstreams []UpstreamBackendYAML `yaml:"upstreams"`
+}
+
+// UpstreamBackendYAML represents a weighted backend target within a reusable upstream.
+type UpstreamBackendYAML struct {
+	URL    string `yaml:"url"`
+	Weight *int   `yaml:"weight,omitempty"`
+}
+
+// UpstreamTimeoutYAML represents the timeout configuration for a reusable upstream.
+type UpstreamTimeoutYAML struct {
+	Connect string `yaml:"connect,omitempty"`
+}
+
 // APIListResponse represents a paginated list of APIs (constitution-compliant)
 type APIListResponse struct {
 	Count      int        `json:"count" yaml:"count"`           // Number of items in current response
 	List       []*API     `json:"list" yaml:"list"`             // Array of API objects
 	Pagination Pagination `json:"pagination" yaml:"pagination"` // Pagination metadata
 }
-