Add code blocks for example

pkg/i2gw/providers/ingressnginx/converter.go

@@ -22,7 +22,7 @@ import (
 	"k8s.io/apimachinery/pkg/util/validation/field"
 )
 
-// converter implements the ConvertHTTPRoutes function of i2gw.ResourceConverter interface.
+// converter implements the ToGatewayAPI function of i2gw.ResourceConverter interface.
 type converter struct {
 	conf *i2gw.ProviderConf
 

provider.md

@@ -13,16 +13,128 @@ A provider must be able to read its custom resources, and convert them.
 * A setup Go development environment.
 
 ## Step-by-Step Implementation
-1. Add a new package under the `providers` package.
+1. Add a new package under the `providers` package. Say we want to add a new gateway provider example.
+```
+.
+├── ingress2gateway.go
+├── ingress2gateway_test.go
+├── provider.go
+└── providers
+    ├── common
+    ├── examplegateway
+    └── ingressnginx
+```
 2. Create a struct named `resourceReader` which implements the `CustomResourceReader` interface in a file named
 `resource_converter.go`.
+```go
+package examplegateway
+
+import (
+	"context"
+
+	"github.com/kubernetes-sigs/ingress2gateway/pkg/i2gw"
+)
+
+// converter implements the i2gw.CustomResourceReader interface.
+type resourceReader struct {
+	conf *i2gw.ProviderConf
+}
+
+// newResourceReader returns a resourceReader instance.
+func newResourceReader(conf *i2gw.ProviderConf) *resourceReader {
+	return &resourceReader{
+		conf: conf,
+	}
+}
+
+func (r *resourceReader) ReadResourcesFromCluster(ctx context.Context, customResources interface{}) error {
+	// read example-gateway related resources from the cluster.
+	return nil
+}
+
+func (r *resourceReader) ReadResourcesFromFiles(ctx context.Context, customResources interface{}, filename string) error {
+	// read example-gateway related resources from the file.
+	return nil
+}
+```
 3. Create a struct named `converter` which implements the `ResourceConverter` interface in a file named `converter.go`.
 The implemented `ToGatewayAPI` function should simply call every registered `featureParser` function, one by one.
 Take a look at `ingressnginx/converter.go` for example.
+```go
+package examplegateway
+
+import (
+	"github.com/kubernetes-sigs/ingress2gateway/pkg/i2gw"
+)
+
+// converter implements the ToGatewayAPI function of i2gw.ResourceConverter interface.
+type converter struct {
+	conf *i2gw.ProviderConf
+
+	featureParsers []i2gw.FeatureParser
+}
+
+// newConverter returns an ingress-nginx converter instance.
+func newConverter(conf *i2gw.ProviderConf) *converter {
+	return &converter{
+		conf: conf,
+		featureParsers: []i2gw.FeatureParser{
+			// The list of feature parsers comes here.
+		},
+	}
+}
+```
 4. Create a new struct named after the provider you are implementing. This struct should embed the previous 2 structs 
 you created.
+```go
+package examplegateway
+
+import (
+	"github.com/kubernetes-sigs/ingress2gateway/pkg/i2gw"
+)
+
+// Provider implements the i2gw.Provider interface.
+type Provider struct {
+	conf *i2gw.ProviderConf
+
+	*resourceReader
+	*converter
+}
+
+// NewProvider constructs and returns the example-gateway implementation of i2gw.Provider.
+func NewProvider(conf *i2gw.ProviderConf) i2gw.Provider {
+	return &Provider{
+		conf:           conf,
+		resourceReader: newResourceReader(conf),
+		converter:      newConverter(conf),
+	}
+}
+```
 5. Add the new provider to `i2gw.ProviderConstructorByName`.
+```go
+package examplegateway
+
+import (
+	"github.com/kubernetes-sigs/ingress2gateway/pkg/i2gw"
+)
+
+// The Name of the provider.
+const Name = "example-gateway-provider"
+
+func init() {
+	i2gw.ProviderConstructorByName[Name] = NewProvider
+}
+```
 6. Import the new package at `cmd/print`.
+```go
+package cmd
+
+import (
+	// Call init function for the providers
+	_ "github.com/kubernetes-sigs/ingress2gateway/pkg/i2gw/providers/ingressnginx"
+	_ "github.com/kubernetes-sigs/ingress2gateway/pkg/i2gw/providers/examplegateway"
+)
+```
 
 ## Creating a feature parser
 In case you want to add support for the conversion of a specific feature within a provider (see for example the canary