add initial support for Apache APISIX provider

Signed-off-by: Navendu Pottekkat <[email protected]>

cmd/print.go

@@ -28,6 +28,7 @@ import (
 	"k8s.io/client-go/tools/clientcmd"
 
 	// Call init function for the providers
+	_ "github.com/kubernetes-sigs/ingress2gateway/pkg/i2gw/providers/apisix"
 	_ "github.com/kubernetes-sigs/ingress2gateway/pkg/i2gw/providers/ingressnginx"
 	_ "github.com/kubernetes-sigs/ingress2gateway/pkg/i2gw/providers/kong"
 )

pkg/i2gw/providers/apisix/README.md

@@ -0,0 +1,7 @@
+# Apache APISIX Provider
+
+The project supports translating Apache APISIX specific annotations.
+
+## Supported Annotations
+
+- `k8s.apisix.apache.org/http-to-https`: When set to true, this annotation can be used to redirect HTTP requests to HTTPS with a `301` status code and with the same URI as the original request.

pkg/i2gw/providers/apisix/annotations.go

@@ -0,0 +1,27 @@
+/*
+Copyright 2024 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package apisix
+
+import "fmt"
+
+const (
+	annotationPrefix = "k8s.apisix.apache.org"
+)
+
+func apisixAnnotation(suffix string) string {
+	return fmt.Sprintf("%s/%s", annotationPrefix, suffix)
+}

pkg/i2gw/providers/apisix/apisix.go

@@ -0,0 +1,75 @@
+/*
+Copyright 2024 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package apisix
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/kubernetes-sigs/ingress2gateway/pkg/i2gw"
+	"k8s.io/apimachinery/pkg/util/validation/field"
+)
+
+// The Name of the provider.
+const Name = "apisix"
+const ApisixIngressClass = "apisix"
+
+func init() {
+	i2gw.ProviderConstructorByName[Name] = NewProvider
+}
+
+// Provider implements the i2gw.Provider interface.
+type Provider struct {
+	storage        *storage
+	resourceReader *resourceReader
+	converter      *converter
+}
+
+// NewProvider constructs and returns the apisix implementation of i2gw.Provider.
+func NewProvider(conf *i2gw.ProviderConf) i2gw.Provider {
+	return &Provider{
+		storage:        newResourcesStorage(),
+		resourceReader: newResourceReader(conf),
+		converter:      newConverter(),
+	}
+}
+
+// ToGatewayAPI converts the received i2gw.InputResources to i2gw.GatewayResources
+// including the kong specific features.
+func (p *Provider) ToGatewayAPI(_ i2gw.InputResources) (i2gw.GatewayResources, field.ErrorList) {
+	return p.converter.convert(p.storage)
+}
+
+func (p *Provider) ReadResourcesFromCluster(ctx context.Context) error {
+	storage, err := p.resourceReader.readResourcesFromCluster(ctx)
+	if err != nil {
+		return fmt.Errorf("failed to read resources from cluster: %w", err)
+	}
+
+	p.storage = storage
+	return nil
+}
+
+func (p *Provider) ReadResourcesFromFile(_ context.Context, filename string) error {
+	storage, err := p.resourceReader.readResourcesFromFile(filename)
+	if err != nil {
+		return fmt.Errorf("failed to read resources from file: %w", err)
+	}
+
+	p.storage = storage
+	return nil
+}

pkg/i2gw/providers/apisix/converter.go

@@ -0,0 +1,64 @@
+/*
+Copyright 2024 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package apisix
+
+import (
+	"github.com/kubernetes-sigs/ingress2gateway/pkg/i2gw"
+	"github.com/kubernetes-sigs/ingress2gateway/pkg/i2gw/providers/common"
+	networkingv1 "k8s.io/api/networking/v1"
+	"k8s.io/apimachinery/pkg/util/validation/field"
+)
+
+// converter implements the ToGatewayAPI function of i2gw.ResourceConverter interface.
+type converter struct {
+	featureParsers                []i2gw.FeatureParser
+	implementationSpecificOptions i2gw.ProviderImplementationSpecificOptions
+}
+
+// newConverter returns an apisix converter instance.
+func newConverter() *converter {
+	return &converter{
+		featureParsers: []i2gw.FeatureParser{
+			httpToHttpsFeature,
+		},
+		implementationSpecificOptions: i2gw.ProviderImplementationSpecificOptions{
+			// The list of the implementationSpecific ingress fields options comes here.
+		},
+	}
+}
+
+func (c *converter) convert(storage *storage) (i2gw.GatewayResources, field.ErrorList) {
+	ingressList := []networkingv1.Ingress{}
+	for _, ing := range storage.Ingresses {
+		ingressList = append(ingressList, *ing)
+	}
+	// Convert plain ingress resources to gateway resources, ignoring all
+	// provider-specific features.
+	gatewayResources, errs := common.ToGateway(ingressList, c.implementationSpecificOptions)
+	if len(errs) > 0 {
+		return i2gw.GatewayResources{}, errs
+	}
+
+	for _, parseFeatureFunc := range c.featureParsers {
+		// Apply the feature parsing function to the gateway resources, one by one.
+		parseErrs := parseFeatureFunc(i2gw.InputResources{Ingresses: ingressList}, &gatewayResources)
+		// Append the parsing errors to the error list.
+		errs = append(errs, parseErrs...)
+	}
+
+	return gatewayResources, errs
+}

pkg/i2gw/providers/apisix/http_to_https.go

@@ -0,0 +1,58 @@
+/*
+Copyright 2024 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package apisix
+
+import (
+	"github.com/kubernetes-sigs/ingress2gateway/pkg/i2gw"
+	"github.com/kubernetes-sigs/ingress2gateway/pkg/i2gw/providers/common"
+	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/apimachinery/pkg/util/validation/field"
+	"k8s.io/utils/ptr"
+	gatewayv1 "sigs.k8s.io/gateway-api/apis/v1"
+)
+
+func httpToHttpsFeature(ingressResources i2gw.InputResources, gatewayResources *i2gw.GatewayResources) field.ErrorList {
+	var errs field.ErrorList
+	httpToHTTPSAnnotation := apisixAnnotation("http-to-https")
+	ruleGroups := common.GetRuleGroups(ingressResources.Ingresses)
+	for _, rg := range ruleGroups {
+		for _, rule := range rg.Rules {
+			if val := rule.Ingress.Annotations[httpToHTTPSAnnotation]; val == "true" {
+				if rule.Ingress.Spec.Rules == nil {
+					continue
+				}
+				key := types.NamespacedName{Namespace: rule.Ingress.Namespace, Name: common.RouteName(rg.Name, rg.Host)}
+				httpRoute, ok := gatewayResources.HTTPRoutes[key]
+				if !ok {
+					errs = append(errs, field.NotFound(field.NewPath("HTTPRoute"), key))
+				}
+
+				for i, rule := range httpRoute.Spec.Rules {
+					rule.Filters = append(rule.Filters, gatewayv1.HTTPRouteFilter{
+						Type: gatewayv1.HTTPRouteFilterRequestRedirect,
+						RequestRedirect: &gatewayv1.HTTPRequestRedirectFilter{
+							Scheme:     ptr.To("https"),
+							StatusCode: ptr.To(int(301)),
+						},
+					})
+					httpRoute.Spec.Rules[i] = rule
+				}
+			}
+		}
+	}
+	return errs
+}