allow setting a replica count in extensions.

Author: hugosantos

internal/frontend/cuefrontendopaque/server.go

@@ -26,20 +26,18 @@ var (
 		"args", "env", "services", "ports", "unstable_permissions", "permissions", "probe", "probes", "security",
 		"sidecars", "mounts", "resources", "requires", "tolerations", "annotations",
 		"resourceLimits", "resourceRequests", "terminationGracePeriodSeconds",
-		"extensions", "nodeSelector",
+		"extensions", "nodeSelector", "replicas",
 		// This is needed for the "spec" in server templates. This can't be a private field, otherwise it can't be overridden.
 		"spec"}
 
 	serverFields = append(slices.Clone(extensionFields),
-		"name", "class", "integration", "image", "imageFrom", "unstable_naming", "replicas", "spec")
+		"name", "class", "integration", "image", "imageFrom", "unstable_naming", "spec")
 )
 
 type cueServer struct {
 	Name  string `json:"name"`
 	Class string `json:"class"`
 
-	Replicas int32 `json:"replicas"`
-
 	cueServerExtension
 }
 
@@ -65,6 +63,8 @@ type cueServerExtension struct {
 
 	TerminationGracePeriodSeconds int64 `json:"terminationGracePeriodSeconds,omitempty"`
 
+	Replicas int32 `json:"replicas"`
+
 	Extensions []string `json:"extensions,omitempty"`
 }
 
@@ -100,7 +100,6 @@ func parseCueServer(ctx context.Context, env *schema.Environment, pl parsing.Ear
 		Name:         bits.Name,
 		Framework:    schema.Framework_OPAQUE,
 		RunByDefault: true,
-		Replicas:     bits.Replicas,
 		Self:         fragment,
 	}
 
@@ -111,9 +110,6 @@ func parseCueServer(ctx context.Context, env *schema.Environment, pl parsing.Ear
 		out.DeployableClass = string(schema.DeployableClass_STATEFUL)
 	case "daemonset", string(schema.DeployableClass_DAEMONSET):
 		out.DeployableClass = string(schema.DeployableClass_DAEMONSET)
-		if bits.Replicas > 0 {
-			return nil, fnerrors.NewWithLocation(loc, "daemon set deployments do not support custom replica counts")
-		}
 	default:
 		return nil, fnerrors.NewWithLocation(loc, "%s: server class is not supported", bits.Class)
 	}
@@ -388,6 +384,10 @@ func parseServerExtension(ctx context.Context, env *schema.Environment, pl parsi
 		})
 	}
 
+	if bits.Replicas > 0 {
+		out.Replicas = bits.Replicas
+	}
+
 	for _, ext := range bits.Extensions {
 		pkg := schema.PackageName(ext)
 		if err := invariants.EnsurePackageLoaded(ctx, pl, loc.PackageName, pkg); err != nil {

internal/planning/deploy/deploy.go

@@ -872,7 +872,7 @@ func PrepareRunOpts(ctx context.Context, stack *planning.Stack, srv planning.Pla
 	out.ErrorLocation = srv.Location
 	out.PackageRef = srv.Proto().GetPackageRef()
 	out.Class = schema.DeployableClass(proto.DeployableClass)
-	out.Replicas = proto.Replicas
+	out.Replicas = frag.Replicas
 	out.Id = proto.Id
 	out.Name = proto.Name
 	out.Volumes = append(out.Volumes, frag.Volume...)

internal/planning/stack.go

@@ -364,6 +364,14 @@ func (cs *computeState) computeServerContents(ctx context.Context, rp *resourceP
 			ps.MergedFragment.NodeSelector = append(ps.MergedFragment.NodeSelector, frag.NodeSelector...)
 			ps.MergedFragment.Listener = append(ps.MergedFragment.Listener, frag.Listener...)
 
+			if frag.Replicas != 0 {
+				if ps.MergedFragment.Replicas != 0 && frag.Replicas != ps.MergedFragment.Replicas {
+					return fnerrors.New("incompatible replicas definition")
+				} else if ps.MergedFragment.Replicas == 0 {
+					ps.MergedFragment.Replicas = frag.Replicas
+				}
+			}
+
 			if frag.Permissions != nil {
 				if ps.MergedFragment.Permissions == nil {
 					ps.MergedFragment.Permissions = &schema.ServerPermissions{}
@@ -699,6 +707,7 @@ func evalProvision(ctx context.Context, secs is.SecretsSource, server Server, no
 		ComputePlanWith: append(slices.Clone(node.ComputePlanWith), combinedProps.ComputePlanWith...),
 		ServerFragments: fragments,
 	}
+
 	parsed.PrepareProps.ProvisionInput = combinedProps.ProvisionInput
 	parsed.PrepareProps.Extension = combinedProps.Extension
 	parsed.PrepareProps.ServerExtension = combinedProps.ServerExtension

internal/versions/versions.json

@@ -1,5 +1,5 @@
 {
-	"api_version": 110,
+	"api_version": 111,
 	"minimum_api_version": 40,
 	"cache_version": 1
 }