[Turbine] Turbine controller (#2223)

spring-cloud-netflix-turbine/src/main/java/org/springframework/cloud/netflix/turbine/ClusterInformation.java

+package org.springframework.cloud.netflix.turbine;
+
+import java.util.Objects;
+
+public class ClusterInformation {
+
+    private final String name;
+    private final String link;
+
+    public ClusterInformation(String name, String link) {
+        this.name = name;
+        this.link = link;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public String getLink() {
+        return link;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        ClusterInformation that = (ClusterInformation) o;
+        return Objects.equals(name, that.name) &&
+                Objects.equals(link, that.link);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(name, link);
+    }
+
+    @Override
+    public String toString() {
+        return "ClusterInformation{" +
+                "name='" + name + '\'' +
+                ", link='" + link + '\'' +
+                '}';
+    }
+}

spring-cloud-netflix-turbine/src/main/java/org/springframework/cloud/netflix/turbine/TurbineController.java

+package org.springframework.cloud.netflix.turbine;
+
+import org.springframework.http.MediaType;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import javax.servlet.http.HttpServletRequest;
+import java.util.Collection;
+
+@RestController
+public class TurbineController {
+
+	private final TurbineInformationService turbineInformationService;
+
+	public TurbineController(TurbineInformationService turbineInformationService) {
+		this.turbineInformationService = turbineInformationService;
+	}
+
+	@GetMapping(value = "/clusters", produces = MediaType.APPLICATION_JSON_VALUE)
+	public Collection<ClusterInformation> clusters(HttpServletRequest request) {
+		return turbineInformationService.getClusterInformations(request);
+	}
+
+}

spring-cloud-netflix-turbine/src/main/java/org/springframework/cloud/netflix/turbine/TurbineInformationService.java

+package org.springframework.cloud.netflix.turbine;
+
+import com.netflix.turbine.data.AggDataFromCluster;
+import com.netflix.turbine.data.DataFromSingleInstance;
+import com.netflix.turbine.monitor.MonitorConsole;
+import com.netflix.turbine.monitor.TurbineDataMonitor;
+import com.netflix.turbine.monitor.cluster.ClusterMonitor;
+import org.springframework.http.server.ServletServerHttpRequest;
+import org.springframework.web.util.UriComponents;
+import org.springframework.web.util.UriComponentsBuilder;
+
+import javax.servlet.http.HttpServletRequest;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+
+import static com.netflix.turbine.monitor.cluster.AggregateClusterMonitor.AggregatorClusterMonitorConsole;
+
+public class TurbineInformationService {
+
+	public Collection<ClusterInformation> getClusterInformations(HttpServletRequest request) {
+		String hostName = getHostName(request);
+		return getClusterInformations(hostName);
+	}
+
+	private Collection<ClusterInformation> getClusterInformations(String hostName) {
+		Collection<TurbineDataMonitor<AggDataFromCluster>> monitors = AggregatorClusterMonitorConsole.getAllMonitors();
+		List<ClusterInformation> clusterInformations = new ArrayList<>();
+		for (TurbineDataMonitor<AggDataFromCluster> monitor : monitors) {
+			ClusterMonitor clusterMonitor = (ClusterMonitor) monitor;
+			MonitorConsole<DataFromSingleInstance> instanceConsole = clusterMonitor.getInstanceMonitors();
+			for (TurbineDataMonitor<DataFromSingleInstance> single : instanceConsole.getAllMonitors()) {
+				String cluster = single.getStatsInstance().getCluster();
+				ClusterInformation info = new ClusterInformation(cluster,
+						getLink(hostName, cluster));
+				clusterInformations.add(info);
+			}
+		}
+		return clusterInformations;
+	}
+
+	private String getLink(String hostName, String cluster) {
+		return hostName + "/turbine.stream?cluster=" + cluster;
+	}
+
+	private String getHostName(HttpServletRequest request) {
+		UriComponents components = UriComponentsBuilder
+				.fromHttpRequest(new ServletServerHttpRequest(request)).build();
+		String host = components.getHost();
+		int port = components.getPort();
+		String scheme = components.getScheme();
+		if (port > -1) {
+			return String.format("%s://%s:%d", scheme, host, port);
+		}
+		return String.format("%s://%s", scheme, host);
+	}
+
+}