docs: add examples for Login, Logout and Credential

example_test.go

@@ -0,0 +1,73 @@
+/*
+Copyright The ORAS 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 credentials_test
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+
+	credentials "github.com/oras-project/oras-credentials-go"
+	"oras.land/oras-go/v2/registry/remote"
+	"oras.land/oras-go/v2/registry/remote/auth"
+)
+
+func ExampleLogin() {
+	store, err := credentials.NewStore("example/path/config.json", credentials.StoreOptions{AllowPlaintextPut: true})
+	if err != nil {
+		panic(err)
+	}
+	registry, err := remote.NewRegistry("example.registry.com")
+	if err != nil {
+		panic(err)
+	}
+	cred := auth.Credential{Username: "username-example", Password: "password-example"}
+	err = credentials.Login(context.Background(), store, registry, cred)
+	if err != nil {
+		panic(err)
+	}
+	fmt.Println("Login succeeded")
+}
+
+func ExampleLogout() {
+	store, err := credentials.NewStore("example/path/config.json", credentials.StoreOptions{})
+	if err != nil {
+		panic(err)
+	}
+	err = credentials.Logout(context.Background(), store, "example.registry.com")
+	if err != nil {
+		panic(err)
+	}
+	fmt.Println("Logout succeeded")
+}
+
+func ExampleCredential() {
+	store, err := credentials.NewStore("example/path/config.json", credentials.StoreOptions{})
+	if err != nil {
+		panic(err)
+	}
+
+	client := auth.Client{}
+	client.Credential = credentials.Credential(store)
+
+	request, err := http.NewRequest(http.MethodGet, "localhost:8080", nil)
+	if err != nil {
+		panic(err)
+	}
+
+	_, err = client.Do(request)
+	if err != nil {
+		panic(err)
+	}
+}