Add ttl CLI parameter and function input value

fn.go

@@ -4,12 +4,14 @@ import (
 	"context"
 	"fmt"
 	"maps"
+	"time"
 
 	"github.com/crossplane-contrib/function-patch-and-transform/input/v1beta1"
 	"github.com/crossplane/crossplane-runtime/v2/pkg/errors"
 	"github.com/crossplane/crossplane-runtime/v2/pkg/fieldpath"
 	"github.com/crossplane/crossplane-runtime/v2/pkg/logging"
 	"github.com/crossplane/crossplane-runtime/v2/pkg/reconciler/managed"
+	"google.golang.org/protobuf/types/known/durationpb"
 	"google.golang.org/protobuf/types/known/structpb"
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
 	"k8s.io/apimachinery/pkg/util/json"
@@ -27,6 +29,7 @@ type Function struct {
 	fnv1.UnimplementedFunctionRunnerServiceServer
 
 	log logging.Logger
+	ttl time.Duration
 }
 
 // RunFunction runs the Function.
@@ -37,14 +40,23 @@ func (f *Function) RunFunction(ctx context.Context, req *fnv1.RunFunctionRequest
 	log.Debug("Running Function")
 
 	// TODO(negz): We can probably use a longer TTL if all resources are ready.
-	rsp := response.To(req, response.DefaultTTL)
+	rsp := response.To(req, f.ttl)
 
 	input := &v1beta1.Resources{}
 	if err := request.GetInput(req, input); err != nil {
 		response.Fatal(rsp, errors.Wrap(err, "cannot get Function input"))
 		return rsp, nil
 	}
 
+	if input.TTL != "" {
+		dur, err := time.ParseDuration(input.TTL)
+		if err != nil {
+			response.Fatal(rsp, errors.Wrapf(err, "cannot set ttl"))
+			return rsp, nil
+		}
+		rsp.Meta.Ttl = durationpb.New(dur)
+	}
+
 	// Our input is an opaque object nested in a Composition, so unfortunately
 	// it won't handle validation for us.
 	if err := ValidateResources(input); err != nil {

fn_test.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"testing"
+	"time"
 
 	"github.com/crossplane-contrib/function-patch-and-transform/input/v1beta1"
 	"github.com/crossplane/crossplane-runtime/v2/pkg/logging"
@@ -1535,7 +1536,7 @@ func TestRunFunction(t *testing.T) {
 
 	for name, tc := range cases {
 		t.Run(name, func(t *testing.T) {
-			f := &Function{log: logging.NewNopLogger()}
+			f := &Function{log: logging.NewNopLogger(), ttl: response.DefaultTTL}
 			rsp, err := f.RunFunction(tc.args.ctx, tc.args.req)
 
 			if diff := cmp.Diff(tc.want.rsp, rsp, protocmp.Transform()); diff != "" {
@@ -1549,6 +1550,39 @@ func TestRunFunction(t *testing.T) {
 	}
 }
 
+func TestRunFunctionCacheTTL(t *testing.T) {
+	f := &Function{log: logging.NewNopLogger(), ttl: response.DefaultTTL}
+	rsp, err := f.RunFunction(context.Background(), &fnv1.RunFunctionRequest{
+		Input: resource.MustStructObject(&v1beta1.Resources{
+			TTL: "5m",
+			Resources: []v1beta1.ComposedTemplate{
+				{
+					Name: "cool-resource",
+					Base: &runtime.RawExtension{Raw: []byte(`{"apiVersion":"example.org/v1","kind":"CD"}`)},
+				},
+			},
+		}),
+		Observed: &fnv1.State{
+			Composite: &fnv1.Resource{
+				Resource: resource.MustStructJSON(`{"apiVersion":"example.org/v1","kind":"XR"}`),
+			},
+		},
+		Desired: &fnv1.State{
+			Composite: &fnv1.Resource{
+				Resource: resource.MustStructJSON(`{"apiVersion":"example.org/v1","kind":"XR"}`),
+			},
+		},
+	})
+	if err != nil {
+		t.Fatalf("RunFunction(...): %v", err)
+	}
+
+	want := durationpb.New(5 * time.Minute)
+	if diff := cmp.Diff(want, rsp.GetMeta().GetTtl(), protocmp.Transform()); diff != "" {
+		t.Errorf("RunFunction(...): -want TTL, +got TTL:\n%s", diff)
+	}
+}
+
 // Crossplane sends as context a fake resource:
 // { "apiVersion": "internal.crossplane.io/v1alpha1", "kind": "Environment", ... the actual environment content ... }
 // See: https://github.com/crossplane/crossplane/blob/806f0d20d146f6f4f1735c5ec6a7dc78923814b3/internal/controller/apiextensions/composite/environment_fetcher.go#L85C1-L85C1

input/v1beta1/resources.go

@@ -36,6 +36,10 @@ type Resources struct {
 	// composite resource is created.
 	Resources []ComposedTemplate `json:"resources"`
 
+	// TTL for which a response can be cached in time.Duration format. Default "1m".
+	// +optional
+	TTL string `json:"ttl,omitempty"`
+
 	// WriteConnectionSecretToRef specifies the name and namespace of a Secret
 	// to which any connection details for this composite resource should be
 	// written. This field is only used for Crossplane v2 composite resources.

main.go

@@ -2,20 +2,24 @@
 package main
 
 import (
+	"time"
+
 	"github.com/alecthomas/kong"
 
 	"github.com/crossplane/function-sdk-go"
+	"github.com/crossplane/function-sdk-go/response"
 )
 
 // CLI of this Function.
 type CLI struct {
 	Debug bool `help:"Emit debug logs in addition to info logs." short:"d"`
 
-	Network            string `default:"tcp"                                                                                        help:"Network on which to listen for gRPC connections."`
-	Address            string `default:":9443"                                                                                      help:"Address at which to listen for gRPC connections."`
-	TLSCertsDir        string `env:"TLS_SERVER_CERTS_DIR"                                                                           help:"Directory containing server certs (tls.key, tls.crt) and the CA used to verify client certificates (ca.crt)"`
-	Insecure           bool   `help:"Run without mTLS credentials. If you supply this flag --tls-server-certs-dir will be ignored."`
-	MaxRecvMessageSize int    `default:"4"                                                                                          help:"Maximum size of received messages in MB."`
+	Network            string         `default:"tcp"                                                                                        help:"Network on which to listen for gRPC connections."`
+	Address            string         `default:":9443"                                                                                      help:"Address at which to listen for gRPC connections."`
+	TLSCertsDir        string         `env:"TLS_SERVER_CERTS_DIR"                                                                           help:"Directory containing server certs (tls.key, tls.crt) and the CA used to verify client certificates (ca.crt)"`
+	Insecure           bool           `help:"Run without mTLS credentials. If you supply this flag --tls-server-certs-dir will be ignored."`
+	MaxRecvMessageSize int            `default:"4"                                                                                          help:"Maximum size of received messages in MB."`
+	TTL                *time.Duration `default:"1m"                                                                                         help:"Time to live for function response."`
 }
 
 // Run this Function.
@@ -25,7 +29,12 @@ func (c *CLI) Run() error {
 		return err
 	}
 
-	return function.Serve(&Function{log: log},
+	ttl := response.DefaultTTL
+	if c.TTL != nil {
+		ttl = *c.TTL
+	}
+
+	return function.Serve(&Function{log: log, ttl: ttl},
 		function.Listen(c.Network, c.Address),
 		function.MTLSCertificates(c.TLSCertsDir),
 		function.Insecure(c.Insecure),

package/input/pt.fn.crossplane.io_resources.yaml

@@ -1286,6 +1286,10 @@ spec:
               - name
               type: object
             type: array
+          ttl:
+            description: TTL for which a response can be cached in time.Duration format.
+              Default "1m".
+            type: string
           writeConnectionSecretToRef:
             description: |-
               WriteConnectionSecretToRef specifies the name and namespace of a Secret