/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.catalina.valves;
import java.io.IOException;
import jakarta.servlet.ServletException;
import jakarta.servlet.http.HttpServletResponse;
import org.apache.catalina.Container;
import org.apache.catalina.Context;
import org.apache.catalina.LifecycleException;
import org.apache.catalina.connector.Request;
import org.apache.catalina.connector.Response;
import org.apache.tomcat.util.buf.MessageBytes;
/**
* Simple Valve that responds to cloud orchestrators health checks.
*/
public class HealthCheckValve extends ValveBase {
private static final String UP = "{ " + " \"status\": \"UP\", " + " \"checks\": [] " + "}";
private static final String DOWN = "{ " + " \"status\": \"DOWN\", " + " \"checks\": [] " + "}";
private String path = "/health";
/**
* Will be set to true if the valve is associated with a context.
*/
protected boolean context = false;
/**
* Check if all child containers are available.
*/
protected boolean checkContainersAvailable = true;
public HealthCheckValve() {
super(true);
}
public final String getPath() {
return path;
}
public final void setPath(String path) {
this.path = path;
}
public boolean getCheckContainersAvailable() {
return this.checkContainersAvailable;
}
public void setCheckContainersAvailable(boolean checkContainersAvailable) {
this.checkContainersAvailable = checkContainersAvailable;
}
@Override
protected void startInternal() throws LifecycleException {
super.startInternal();
context = (getContainer() instanceof Context);
}
@Override
public void invoke(Request request, Response response) throws IOException, ServletException {
MessageBytes urlMB = context ? request.getRequestPathMB() : request.getDecodedRequestURIMB();
if (urlMB.equals(path)) {
response.setContentType("application/json");
if (!checkContainersAvailable || isAvailable(getContainer())) {
response.getOutputStream().print(UP);
} else {
response.setStatus(HttpServletResponse.SC_SERVICE_UNAVAILABLE);
response.getOutputStream().print(DOWN);
}
} else {
getNext().invoke(request, response);
}
}
protected boolean isAvailable(Container container) {
for (Container child : container.findChildren()) {
if (!isAvailable(child)) {
return false;
}
}
return container.getState().isAvailable();
}
}