#562 Adding module spring-cloud-kubernetes-loadbalancer with implementation for service mode

pom.xml

@@ -96,6 +96,7 @@
 		<module>spring-cloud-kubernetes-istio</module>
 		<module>spring-cloud-kubernetes-integration-tests</module>
 		<module>docs</module>
+		<module>spring-cloud-kubernetes-loadbalancer</module>
 	</modules>
 
 	<dependencyManagement>

spring-cloud-kubernetes-loadbalancer/pom.xml

@@ -0,0 +1,45 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+		 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<parent>
+		<artifactId>spring-cloud-kubernetes</artifactId>
+		<groupId>org.springframework.cloud</groupId>
+		<version>2.0.0-SNAPSHOT</version>
+	</parent>
+	<modelVersion>4.0.0</modelVersion>
+
+	<artifactId>spring-cloud-kubernetes-loadbalancer</artifactId>
+	<name>Spring Cloud Kubernetes :: Load Balancer</name>
+
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.cloud</groupId>
+			<artifactId>spring-cloud-starter-loadbalancer</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.cloud</groupId>
+			<artifactId>spring-cloud-kubernetes-discovery</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>commons-lang</groupId>
+			<artifactId>commons-lang</artifactId>
+			<version>2.6</version>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-actuator</artifactId>
+			<optional>true</optional>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-configuration-processor</artifactId>
+			<optional>true</optional>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+</project>

spring-cloud-kubernetes-loadbalancer/src/main/java/org/springframework/cloud/kubernetes/loadbalancer/KubernetesClientConfiguration.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2013-2020 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.cloud.kubernetes.loadbalancer;
+
+import io.fabric8.kubernetes.client.KubernetesClient;
+
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.context.annotation.Bean;
+import org.springframework.core.env.Environment;
+
+/**
+ * Kubernetes load balancer client properties.
+ *
+ * @author Piotr Minkowski
+ */
+public class KubernetesClientConfiguration {
+
+	@Bean
+	@ConditionalOnProperty(name = "spring.cloud.kubernetes.loadbalancer.mode",
+			havingValue = "SERVICE")
+	KubernetesServicesListSupplier kubernetesServicesListSupplier(Environment environment,
+			KubernetesClient kubernetesClient, KubernetesServiceInstanceMapper mapper) {
+		return new KubernetesServicesListSupplier(environment, kubernetesClient, mapper);
+	}
+
+}

spring-cloud-kubernetes-loadbalancer/src/main/java/org/springframework/cloud/kubernetes/loadbalancer/KubernetesLoadBalancerAutoConfiguration.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2013-2020 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.cloud.kubernetes.loadbalancer;
+
+import org.springframework.cloud.kubernetes.discovery.KubernetesDiscoveryProperties;
+import org.springframework.cloud.loadbalancer.annotation.LoadBalancerClients;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+/**
+ * @author Piotr Minkowski
+ */
+@Configuration
+@LoadBalancerClients(defaultConfiguration = KubernetesClientConfiguration.class)
+public class KubernetesLoadBalancerAutoConfiguration {
+
+	@Bean
+	KubernetesLoadBalancerProperties properties() {
+		return new KubernetesLoadBalancerProperties();
+	}
+
+	@Bean
+	KubernetesServiceInstanceMapper mapper(KubernetesLoadBalancerProperties properties,
+			KubernetesDiscoveryProperties discoveryProperties) {
+		return new KubernetesServiceInstanceMapper(properties, discoveryProperties);
+	}
+
+}

spring-cloud-kubernetes-loadbalancer/src/main/java/org/springframework/cloud/kubernetes/loadbalancer/KubernetesLoadBalancerMode.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2013-2019 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.cloud.kubernetes.loadbalancer;
+
+/**
+ * @author Piotr Minkowski
+ */
+public enum KubernetesLoadBalancerMode {
+
+	/**
+	 * using pod ip and port.
+	 */
+	POD,
+	/**
+	 * using kubernetes service name and port.
+	 */
+	SERVICE
+
+}

spring-cloud-kubernetes-loadbalancer/src/main/java/org/springframework/cloud/kubernetes/loadbalancer/KubernetesLoadBalancerProperties.java

@@ -0,0 +1,112 @@
+/*
+ * Copyright 2013-2020 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.cloud.kubernetes.loadbalancer;
+
+import org.springframework.boot.context.properties.ConfigurationProperties;
+
+/**
+ * @author Piotr Minkowski
+ */
+@ConfigurationProperties(prefix = "spring.cloud.kubernetes.loadbalancer")
+public class KubernetesLoadBalancerProperties {
+
+	/**
+	 * Ribbon enabled,default true.
+	 */
+	private Boolean enabled = true;
+
+	/**
+	 * {@link KubernetesLoadBalancerMode} setting ribbon server list with ip of pod or
+	 * service name. default value is POD.
+	 */
+	private KubernetesLoadBalancerMode mode = KubernetesLoadBalancerMode.POD;
+
+	/**
+	 * cluster domain.
+	 */
+	private String clusterDomain = "cluster.local";
+
+	/**
+	 * service port name.
+	 */
+	private String portName = "http";
+
+	/**
+	 * Get cluster domain.
+	 * @return the cluster domain
+	 */
+	public String getClusterDomain() {
+		return clusterDomain;
+	}
+
+	/**
+	 * Sets cluster domain.
+	 * @param clusterDomain the cluster domain
+	 */
+	public void setClusterDomain(String clusterDomain) {
+		this.clusterDomain = clusterDomain;
+	}
+
+	/**
+	 * Gets mode.
+	 * @return the mode
+	 */
+	public KubernetesLoadBalancerMode getMode() {
+		return mode;
+	}
+
+	/**
+	 * Sets mode.
+	 * @param mode the mode
+	 */
+	public void setMode(KubernetesLoadBalancerMode mode) {
+		this.mode = mode;
+	}
+
+	/**
+	 * Gets enabled.
+	 * @return the enabled
+	 */
+	public Boolean getEnabled() {
+		return enabled;
+	}
+
+	/**
+	 * Sets enabled.
+	 * @param enabled the enabled
+	 */
+	public void setEnabled(Boolean enabled) {
+		this.enabled = enabled;
+	}
+
+	/**
+	 * Gets portName.
+	 * @return portName port name
+	 */
+	public String getPortName() {
+		return portName;
+	}
+
+	/**
+	 * Sets portName.
+	 * @param portName port name
+	 */
+	public void setPortName(String portName) {
+		this.portName = portName;
+	}
+
+}

spring-cloud-kubernetes-loadbalancer/src/main/java/org/springframework/cloud/kubernetes/loadbalancer/KubernetesServiceInstance.java

@@ -0,0 +1,84 @@
+/*
+ * Copyright 2013-2020 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.cloud.kubernetes.loadbalancer;
+
+import java.net.URI;
+import java.util.Map;
+
+import org.springframework.cloud.client.ServiceInstance;
+
+/**
+ * @author Piotr Minkowski
+ */
+public class KubernetesServiceInstance implements ServiceInstance {
+
+	private String serviceId;
+
+	private String instanceId;
+
+	private int port;
+
+	private boolean secure;
+
+	private String host;
+
+	private URI uri;
+
+	private Map<String, String> metadata;
+
+	KubernetesServiceInstance(String serviceId, String instanceId, int port,
+			boolean secure, String host, URI uri, Map<String, String> metadata) {
+		this.serviceId = serviceId;
+		this.instanceId = instanceId;
+		this.port = port;
+		this.secure = secure;
+		this.host = host;
+		this.uri = uri;
+		this.metadata = metadata;
+	}
+
+	@Override
+	public String getServiceId() {
+		return serviceId;
+	}
+
+	@Override
+	public String getHost() {
+		return host;
+	}
+
+	@Override
+	public int getPort() {
+		return port;
+	}
+
+	@Override
+	public boolean isSecure() {
+		return secure;
+	}
+
+	@Override
+	public URI getUri() {
+		return uri;
+	}
+
+	@Override
+	public Map<String, String> getMetadata() {
+		return metadata;
+	}
+
+}

spring-cloud-kubernetes-loadbalancer/src/main/java/org/springframework/cloud/kubernetes/loadbalancer/KubernetesServiceInstanceMapper.java

@@ -0,0 +1,140 @@
+/*
+ * Copyright 2013-2020 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.cloud.kubernetes.loadbalancer;
+
+import java.net.URI;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+
+import io.fabric8.kubernetes.api.model.ObjectMeta;
+import io.fabric8.kubernetes.api.model.Service;
+import io.fabric8.kubernetes.api.model.ServicePort;
+import io.fabric8.kubernetes.client.utils.Utils;
+import org.apache.commons.lang.StringUtils;
+
+import org.springframework.cloud.kubernetes.discovery.KubernetesDiscoveryProperties;
+
+/**
+ * @author Piotr Minkowski
+ */
+public class KubernetesServiceInstanceMapper {
+
+	private static final String DSL = "//";
+
+	private static final String COLON = ":";
+
+	private final KubernetesLoadBalancerProperties properties;
+
+	private final KubernetesDiscoveryProperties discoveryProperties;
+
+	KubernetesServiceInstanceMapper(KubernetesLoadBalancerProperties properties,
+			KubernetesDiscoveryProperties discoveryProperties) {
+		this.properties = properties;
+		this.discoveryProperties = discoveryProperties;
+	}
+
+	public KubernetesServiceInstance map(Service service) {
+		final ObjectMeta meta = service.getMetadata();
+		final List<ServicePort> ports = service.getSpec().getPorts();
+		ServicePort port = null;
+		if (ports.size() == 1) {
+			port = ports.get(0);
+		}
+		else if (ports.size() > 1
+				&& Utils.isNotNullOrEmpty(this.properties.getPortName())) {
+			Optional<ServicePort> optPort = ports.stream()
+					.filter(it -> properties.getPortName().endsWith(it.getName()))
+					.findAny();
+			if (optPort.isPresent()) {
+				port = optPort.get();
+			}
+		}
+		if (port == null) {
+			return null;
+		}
+		final String host = createHost(service);
+		final boolean secure = isSecure(service, port);
+		return new KubernetesServiceInstance(meta.getName(), meta.getUid(),
+				port.getPort(), secure, host,
+				createUri(secure ? "https" : "http", host, port.getPort()),
+				getServiceMetadata(service));
+	}
+
+	private Map<String, String> getServiceMetadata(Service service) {
+		final Map<String, String> serviceMetadata = new HashMap<>();
+		KubernetesDiscoveryProperties.Metadata metadataProps = this.discoveryProperties
+				.getMetadata();
+		if (metadataProps.isAddLabels()) {
+			Map<String, String> labelMetadata = getMapWithPrefixedKeys(
+					service.getMetadata().getLabels(), metadataProps.getLabelsPrefix());
+			serviceMetadata.putAll(labelMetadata);
+		}
+		if (metadataProps.isAddAnnotations()) {
+			Map<String, String> annotationMetadata = getMapWithPrefixedKeys(
+					service.getMetadata().getAnnotations(),
+					metadataProps.getAnnotationsPrefix());
+			serviceMetadata.putAll(annotationMetadata);
+		}
+
+		return serviceMetadata;
+	}
+
+	private Map<String, String> getMapWithPrefixedKeys(Map<String, String> map,
+			String prefix) {
+		if (map == null) {
+			return new HashMap<>();
+		}
+		if (!org.springframework.util.StringUtils.hasText(prefix)) {
+			return map;
+		}
+		final Map<String, String> result = new HashMap<>();
+		map.forEach((k, v) -> result.put(prefix + k, v));
+		return result;
+	}
+
+	private boolean isSecure(Service service, ServicePort port) {
+		final String securedLabelValue = service.getMetadata().getLabels()
+				.getOrDefault("secured", "false");
+		if (securedLabelValue.equals("true")) {
+			return true;
+		}
+		final String securedAnnotationValue = service.getMetadata().getAnnotations()
+				.getOrDefault("secured", "false");
+		if (securedAnnotationValue.equals("true")) {
+			return true;
+		}
+		return (port.getName() != null && port.getName().endsWith("https"))
+				|| port.getPort().toString().endsWith("443");
+	}
+
+	private String createHost(Service service) {
+		return String.format("%s.%s.svc.%s", service.getMetadata().getName(),
+				StringUtils.isNotBlank(service.getMetadata().getNamespace())
+						? service.getMetadata().getNamespace() : "default",
+				properties.getClusterDomain());
+	}
+
+	private URI createUri(String scheme, String host, int port) {
+		StringBuilder sb = new StringBuilder();
+		sb.append(scheme).append(COLON).append(DSL).append(host).append(COLON)
+				.append(port);
+		return URI.create(sb.toString());
+	}
+
+}

spring-cloud-kubernetes-loadbalancer/src/main/java/org/springframework/cloud/kubernetes/loadbalancer/KubernetesServicesListSupplier.java

@@ -0,0 +1,69 @@
+/*
+ * Copyright 2013-2020 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.cloud.kubernetes.loadbalancer;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import io.fabric8.kubernetes.api.model.Service;
+import io.fabric8.kubernetes.client.KubernetesClient;
+import org.apache.commons.lang.StringUtils;
+import reactor.core.publisher.Flux;
+
+import org.springframework.cloud.client.ServiceInstance;
+import org.springframework.cloud.loadbalancer.core.ServiceInstanceListSupplier;
+import org.springframework.cloud.loadbalancer.support.LoadBalancerClientFactory;
+import org.springframework.core.env.Environment;
+
+/**
+ * @author Piotr Minkowski
+ */
+public class KubernetesServicesListSupplier implements ServiceInstanceListSupplier {
+
+	private Environment environment;
+
+	private KubernetesClient kubernetesClient;
+
+	private KubernetesServiceInstanceMapper mapper;
+
+	KubernetesServicesListSupplier(Environment environment,
+			KubernetesClient kubernetesClient, KubernetesServiceInstanceMapper mapper) {
+		this.environment = environment;
+		this.kubernetesClient = kubernetesClient;
+		this.mapper = mapper;
+	}
+
+	@Override
+	public String getServiceId() {
+		return environment.getProperty(LoadBalancerClientFactory.PROPERTY_NAME);
+	}
+
+	@Override
+	public Flux<List<ServiceInstance>> get() {
+		List<ServiceInstance> result = new ArrayList<>();
+		Service service = StringUtils.isNotBlank(this.kubernetesClient.getNamespace())
+				? this.kubernetesClient
+						.services().inNamespace(this.kubernetesClient.getNamespace())
+						.withName(this.getServiceId()).get()
+				: this.kubernetesClient.services().withName(this.getServiceId()).get();
+		if (service != null) {
+			result.add(mapper.map(service));
+		}
+		return Flux.just(result);
+	}
+
+}

spring-cloud-kubernetes-loadbalancer/src/main/resources/META-INF/spring.factories

@@ -0,0 +1,2 @@
+org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
+org.springframework.cloud.kubernetes.loadbalancer.KubernetesLoadBalancerAutoConfiguration