Possible to define multiple sequencing rules

Signed-off-by: Hasan Turken <[email protected]>

Author: turkenh

example/composition.yaml

@@ -70,7 +70,10 @@ spec:
     input:
       apiVersion: template.fn.crossplane.io/v1beta1
       kind: Input
-      sequence:
-      - first-resource
-      - second-resource
-      - third-resource
+      rules:
+        - sequence:
+          - first-resource
+          - second-resource
+        - sequence:
+          - first-resource
+          - third-resource

fn.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"fmt"
 	"github.com/crossplane/function-sdk-go/resource"
 
 	"github.com/crossplane/crossplane-runtime/pkg/errors"
@@ -31,9 +32,6 @@ func (f *Function) RunFunction(_ context.Context, req *fnv1beta1.RunFunctionRequ
 		return rsp, nil
 	}
 
-	response.Normalf(rsp, "I was run with input %q!", in.Sequence)
-	f.log.Info("I was run!", "input", in.Sequence)
-
 	//  Get the desired composed resources from the request.
 	desiredComposed, err := request.GetDesiredComposedResources(req)
 	if err != nil {
@@ -47,22 +45,32 @@ func (f *Function) RunFunction(_ context.Context, req *fnv1beta1.RunFunctionRequ
 		return rsp, nil
 	}
 
-	for i, r := range in.Sequence {
-		if i == 0 {
-			// We don't need to do anything for the first resource in the sequence.
-			continue
-		}
-		if _, created := observedComposed[r]; created {
-			// We've already created this resource, so we don't need to do anything.
-			// We only sequence creation of resources that don't exist yet.
-			continue
-		}
-		for _, before := range in.Sequence[:i] {
-			if b, ok := desiredComposed[before]; !ok || b.Ready != resource.ReadyTrue {
-				// A resource that should exist before this one is not in the desired list, or it is not ready yet.
-				// So, we should not create the resource waiting for it yet.
-				delete(desiredComposed, r)
-				break
+	sequences := make([][]resource.Name, 0, len(in.Rules))
+	for _, rule := range in.Rules {
+		sequences = append(sequences, rule.Sequence)
+	}
+
+	for _, sequence := range sequences {
+		for i, r := range sequence {
+			if i == 0 {
+				// We don't need to do anything for the first resource in the sequence.
+				continue
+			}
+			if _, created := observedComposed[r]; created {
+				// We've already created this resource, so we don't need to do anything.
+				// We only sequence creation of resources that don't exist yet.
+				continue
+			}
+			for _, before := range sequence[:i] {
+				if b, ok := desiredComposed[before]; !ok || b.Ready != resource.ReadyTrue {
+					// A resource that should exist before this one is not in the desired list, or it is not ready yet.
+					// So, we should not create the resource waiting for it yet.
+					msg := fmt.Sprintf("Delaying creation of resource %q because %q is not ready or does not exist yet", r, before)
+					response.Normal(rsp, msg)
+					f.log.Info(msg)
+					delete(desiredComposed, r)
+					break
+				}
 			}
 		}
 	}

input/v1beta1/input.go

@@ -12,8 +12,11 @@ import (
 // This isn't a custom resource, in the sense that we never install its CRD.
 // It is a KRM-like object, so we generate a CRD to describe its schema.
 
-// TODO: Add your input type here! It doesn't need to be called 'Input', you can
-// rename it to anything you like.
+type SequencingRule struct {
+	// TODO: InferFromUsages
+	// InferFromUsages bool            `json:"inferFromUsages,omitempty"`
+	Sequence []resource.Name `json:"sequence,omitempty"`
+}
 
 // Input can be used to provide input to this Function.
 // +kubebuilder:object:root=true
@@ -23,5 +26,5 @@ type Input struct {
 	metav1.TypeMeta   `json:",inline"`
 	metav1.ObjectMeta `json:"metadata,omitempty"`
 
-	Sequence []resource.Name `json:"sequence"`
+	Rules []SequencingRule `json:"rules"`
 }

input/v1beta1/zz_generated.deepcopy.go

@@ -33,14 +33,20 @@ spec:
             type: string
           metadata:
             type: object
-          sequence:
+          rules:
             items:
-              description: A Name uniquely identifies a composed resource within a
-                Composition Function pipeline. It's not the resource's metadata.name.
-              type: string
+              properties:
+                sequence:
+                  description: 'TODO: InferFromUsages InferFromUsages bool            `json:"inferFromUsages,omitempty"`'
+                  items:
+                    description: A Name uniquely identifies a composed resource within
+                      a Composition Function pipeline. It's not the resource's metadata.name.
+                    type: string
+                  type: array
+              type: object
             type: array
         required:
-        - sequence
+        - rules
         type: object
     served: true
     storage: true