Add Kotlin WebFlux sample

Issue: gh-5558

samples/boot/kotlin-webflux/spring-security-samples-boot-kotlin-webflux.gradle.kts

@@ -0,0 +1,41 @@
+import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
+
+plugins {
+    id("io.spring.convention.spring-sample-boot")
+	kotlin("jvm")
+	kotlin("plugin.spring") version "1.3.71"
+}
+
+repositories {
+	mavenCentral()
+}
+
+dependencies {
+    implementation(project(":spring-security-core"))
+    implementation(project(":spring-security-config"))
+    implementation(project(":spring-security-web"))
+	implementation("org.springframework.boot:spring-boot-starter-webflux")
+    implementation("org.springframework.boot:spring-boot-starter-thymeleaf")
+    implementation("org.thymeleaf.extras:thymeleaf-extras-springsecurity5")
+	implementation("io.projectreactor.kotlin:reactor-kotlin-extensions")
+	implementation("org.jetbrains.kotlin:kotlin-reflect")
+	implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8")
+	implementation("org.jetbrains.kotlinx:kotlinx-coroutines-reactor")
+
+    testImplementation(project(":spring-security-test"))
+	testImplementation("org.springframework.boot:spring-boot-starter-test") {
+		exclude(group = "org.junit.vintage", module = "junit-vintage-engine")
+	}
+	testImplementation("io.projectreactor:reactor-test")
+}
+
+tasks.withType<Test> {
+	useJUnitPlatform()
+}
+
+tasks.withType<KotlinCompile> {
+	kotlinOptions {
+		freeCompilerArgs = listOf("-Xjsr305=strict")
+		jvmTarget = "1.8"
+	}
+}

samples/boot/kotlin-webflux/src/main/kotlin/org/springframework/security/samples/KotlinWebfluxApplication.kt

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2002-2020 the original author or 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
+ *
+ *      https://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 org.springframework.security.samples
+
+import org.springframework.boot.autoconfigure.SpringBootApplication
+import org.springframework.boot.runApplication
+
+@SpringBootApplication
+class KotlinWebfluxApplication
+
+fun main(args: Array<String>) {
+	runApplication<KotlinWebfluxApplication>(*args)
+}

samples/boot/kotlin-webflux/src/main/kotlin/org/springframework/security/samples/config/SecurityConfig.kt

@@ -0,0 +1,56 @@
+/*
+ * Copyright 2002-2020 the original author or 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
+ *
+ *      https://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 org.springframework.security.samples.config
+
+import org.springframework.context.annotation.Bean
+import org.springframework.security.config.Customizer
+import org.springframework.security.config.annotation.web.reactive.EnableWebFluxSecurity
+import org.springframework.security.config.web.server.ServerHttpSecurity
+import org.springframework.security.config.web.server.invoke
+import org.springframework.security.core.userdetails.MapReactiveUserDetailsService
+import org.springframework.security.core.userdetails.ReactiveUserDetailsService
+import org.springframework.security.core.userdetails.User
+import org.springframework.security.web.server.SecurityWebFilterChain
+
+@EnableWebFluxSecurity
+class SecurityConfig {
+
+    @Bean
+    fun springSecurityFilterChain(http: ServerHttpSecurity): SecurityWebFilterChain {
+        return http {
+            authorizeExchange {
+                authorize("/log-in", permitAll)
+                authorize("/", permitAll)
+                authorize("/css/**", permitAll)
+                authorize("/user/**", hasAuthority("ROLE_USER"))
+            }
+            formLogin {
+                loginPage = "/log-in"
+            }
+        }
+    }
+
+    @Bean
+    fun userDetailsService(): ReactiveUserDetailsService {
+        val userDetails = User.withDefaultPasswordEncoder()
+                .username("user")
+                .password("password")
+                .roles("USER")
+                .build()
+        return MapReactiveUserDetailsService(userDetails)
+    }
+}

samples/boot/kotlin-webflux/src/main/kotlin/org/springframework/security/samples/web/MainController.kt

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2002-2020 the original author or 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
+ *
+ *      https://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 org.springframework.security.samples.web
+
+import org.springframework.stereotype.Controller
+import org.springframework.web.bind.annotation.GetMapping
+
+@Controller
+class MainController {
+
+    @GetMapping("/")
+    fun index(): String {
+        return "index"
+    }
+
+    @GetMapping("/user/index")
+    fun userIndex(): String {
+        return "user/index"
+    }
+
+    @GetMapping("/log-in")
+    fun login(): String {
+        return "login"
+    }
+}

samples/boot/kotlin-webflux/src/main/resources/application.yml

@@ -0,0 +1,6 @@
+server:
+  port: 8080
+
+spring:
+  thymeleaf:
+    cache: false

samples/boot/kotlin-webflux/src/main/resources/css/main.css

@@ -0,0 +1,8 @@
+body {
+    font-family: sans;
+    font-size: 1em;
+}
+
+div.logout {
+    float: right;
+}

samples/boot/kotlin-webflux/src/main/resources/templates/index.html

@@ -0,0 +1,24 @@
+<!DOCTYPE html>
+<html xmlns="http://www.w3.org/1999/xhtml" xmlns:th="https://www.thymeleaf.org" xmlns:sec="https://www.thymeleaf.org/thymeleaf-extras-springsecurity5">
+    <head>
+        <title>Hello Spring Security</title>
+        <meta charset="utf-8" />
+        <link rel="stylesheet" href="/static/css/main.css" th:href="@{/css/main.css}" />
+    </head>
+    <body>
+        <div th:fragment="logout" class="logout" sec:authorize="isAuthenticated()">
+            Logged in user: <span sec:authentication="name"></span> |
+            Roles: <span sec:authentication="principal.authorities"></span>
+            <div>
+                <form action="#" th:action="@{/logout}" method="post">
+                    <input type="submit" value="Logout" />
+                </form>
+            </div>
+        </div>
+        <h1>Hello Spring Security</h1>
+        <p>This is an unsecured page, but you can access the secured pages after authenticating.</p>
+        <ul>
+            <li>Go to the <a href="/user/index" th:href="@{/user/index}">secured pages</a></li>
+        </ul>
+    </body>
+</html>

samples/boot/kotlin-webflux/src/main/resources/templates/login.html

@@ -0,0 +1,20 @@
+<!DOCTYPE html>
+<html xmlns="http://www.w3.org/1999/xhtml" xmlns:th="https://www.thymeleaf.org">
+    <head>
+        <title>Login page</title>
+        <meta charset="utf-8" />
+        <link rel="stylesheet" href="/static/css/main.css" th:href="@{/css/main.css}" />
+	</head>
+    <body>
+        <h1>Login page</h1>
+        <p>Example user: user / password</p>
+        <form th:action="@{/log-in}" method="post">
+            <label for="username">Username</label>:
+            <input type="text" id="username" name="username" autofocus="autofocus" /> <br />
+            <label for="password">Password</label>:
+            <input type="password" id="password" name="password" /> <br />
+            <input type="submit" value="Log in" />
+        </form>
+        <p><a href="/" th:href="@{/}">Back to home page</a></p>
+    </body>
+</html>

samples/boot/kotlin-webflux/src/main/resources/templates/user/index.html

@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<html xmlns="http://www.w3.org/1999/xhtml" xmlns:th="https://www.thymeleaf.org">
+    <head>
+        <title>Hello Spring Security</title>
+        <meta charset="utf-8" />
+        <link rel="stylesheet" href="/static/css/main.css" th:href="@{/css/main.css}" />
+    </head>
+    <body>
+        <div th:substituteby="index::logout"></div>
+        <h1>This is a secured page!</h1>
+        <p><a href="/" th:href="@{/}">Back to home page</a></p>
+    </body>
+</html>

samples/boot/kotlin-webflux/src/test/kotlin/org/springframework/security/samples/KotlinWebfluxApplicationTests.kt

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2002-2020 the original author or 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
+ *
+ *      https://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 org.springframework.security.samples
+
+import org.junit.jupiter.api.Test
+import org.springframework.beans.factory.annotation.Autowired
+import org.springframework.boot.test.context.SpringBootTest
+import org.springframework.context.ApplicationContext
+import org.springframework.test.web.reactive.server.WebTestClient
+import org.springframework.security.test.context.support.WithMockUser
+
+@SpringBootTest
+class KotlinWebfluxApplicationTests {
+
+    lateinit var rest: WebTestClient
+
+    @Autowired
+    fun setup(context: ApplicationContext) {
+        rest = WebTestClient
+                .bindToApplicationContext(context)
+                .configureClient()
+                .build()
+    }
+
+    @Test
+    fun `index page is not protected`() {
+        rest
+                .get()
+                .uri("/")
+                .exchange()
+                .expectStatus().isOk
+    }
+
+    @Test
+    fun `protected page when unauthenticated then redirects to login `() {
+        rest
+                .get()
+                .uri("/user/index")
+                .exchange()
+                .expectStatus().is3xxRedirection
+                .expectHeader().valueEquals("Location", "/log-in")
+    }
+
+    @Test
+    @WithMockUser
+    fun `protected page can be accessed when authenticated`() {
+        rest
+                .get()
+                .uri("/user/index")
+                .exchange()
+                .expectStatus().isOk
+    }
+}