generate policies using go generate

Author: Artem Ivanov

apis/v1alpha1/policy_methods.go

@@ -0,0 +1,70 @@
+package main
+
+import (
+	"log"
+	"os"
+	"text/template"
+)
+
+//go:generate go run gen_policies.go
+
+// Define policy types
+var policies = []struct {
+	Name         string
+	HasSingleRef bool // true if it uses a single TargetRef, false if it uses TargetRefs
+}{
+	{"ClientSettingsPolicy", true},
+	{"ObservabilityPolicy", false},
+	{"UpstreamSettingsPolicy", false},
+}
+
+// Template for generating policy methods
+const tmpl = `// Code generated by gen_policies.go; DO NOT EDIT.
+
+package v1alpha1
+
+import "sigs.k8s.io/gateway-api/apis/v1alpha2"
+
+{{- range . }}
+
+func (p *{{ .Name }}) GetTargetRefs() []v1alpha2.LocalPolicyTargetReference {
+    {{- if .HasSingleRef }}
+    return []v1alpha2.LocalPolicyTargetReference{p.Spec.TargetRef}
+    {{- else }}
+    return p.Spec.TargetRefs
+    {{- end }}
+}
+
+func (p *{{ .Name }}) GetPolicyStatus() v1alpha2.PolicyStatus {
+    return p.Status
+}
+
+func (p *{{ .Name }}) SetPolicyStatus(status v1alpha2.PolicyStatus) {
+    p.Status = status
+}
+
+{{- end }}
+`
+
+func main() {
+	// Ensure the output directory exists
+	outputDir := "../apis/v1alpha1"
+	if err := os.MkdirAll(outputDir, os.ModePerm); err != nil {
+		log.Fatalf("failed to create directory: %v", err)
+	}
+
+	// Open the output file
+	file, err := os.Create("../policy_methods.go")
+	if err != nil {
+		log.Fatalf("failed to create file: %v", err)
+	}
+	defer file.Close()
+
+	// Create a template and execute it with the policy list
+	t := template.Must(template.New("policy").Parse(tmpl))
+	if err := t.Execute(file, policies); err != nil {
+		log.Fatalf("failed to execute template: %v", err)
+	}
+
+	log.Printf("Writing PolicyMethods to %s... Done\n", "policy_methods.go")
+}

apis/v1alpha1/tools/gen_policies.go

@@ -0,0 +1,59 @@
+package main
+
+import (
+	"log"
+	"os"
+	"text/template"
+)
+
+//go:generate go run gen_policies.go
+
+// Define policy types
+var policies = []string{
+	"ObservabilityPolicy",
+}
+
+// Template for generating policy methods
+const tmpl = `// Code generated by gen_policies.go; DO NOT EDIT.
+
+package v1alpha2
+
+import "sigs.k8s.io/gateway-api/apis/v1alpha2"
+
+{{ range . }}
+func (p *{{ . }}) GetTargetRefs() []v1alpha2.LocalPolicyTargetReference {
+    return p.Spec.TargetRefs
+}
+
+func (p *{{ . }}) GetPolicyStatus() v1alpha2.PolicyStatus {
+    return p.Status
+}
+
+func (p *{{ . }}) SetPolicyStatus(status v1alpha2.PolicyStatus) {
+    p.Status = status
+}
+{{ end }}
+`
+
+func main() {
+	// Ensure the output directory exists
+	outputDir := "../apis/v1alpha2"
+	if err := os.MkdirAll(outputDir, os.ModePerm); err != nil {
+		log.Fatalf("failed to create directory: %v", err)
+	}
+
+	// Open the output file
+	file, err := os.Create("../policy_methods.go")
+	if err != nil {
+		log.Fatalf("failed to create file: %v", err)
+	}
+	defer file.Close()
+
+	// Create a template and execute it with the policy list
+	t := template.Must(template.New("policy").Parse(tmpl))
+	if err := t.Execute(file, policies); err != nil {
+		log.Fatalf("failed to execute template: %v", err)
+	}
+
+	log.Printf("Writing PolicyMethods to %s... Done\n", "policy_methods.go")
+}