详解如何通过tomcat的ManagerServlet远程部署项目

介绍

之前在邮政实习时，leader让我阅读tomcat的源代码，尝试自己实现远程部署项目的功能，于是便有了这此实践。
在Tomact中有一个Manager应用程序，它是用来管理已经部署的web应用程序，在这个应用程序中，ManagerServlet是他的主servlet，通过它我们可以获取tomcat的部分指标，远程管理web应用程序，不过这个功能会受到web应用程序部署中安全约束的保护。

当你请求ManagerServlet时，它会检查getPathInfo()返回的值以及相关的查询参数，以确定被请求的操作。它支持以下操作和参数(从servlet路径开始):

我们可以通过ManagerServlet中getPathInfo()提供的操作，将自己的项目远程部署到服务器上，下面将贴出我的实践代码，在实践它之前你只需要引入httpclient包和commons包。

封装统一的远程请求管理类

封装此类用于方便client请求ManagerServlet：

import java.io.File;
import java.net.URL;
import java.net.URLEncoder;

import org.apache.commons.io.IOUtils;
import org.apache.commons.lang.StringUtils;
import org.apache.http.Header;
import org.apache.http.HttpHost;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.Credentials;
import org.apache.http.auth.UsernamePasswordCredentials;
import org.apache.http.client.AuthCache;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpRequestBase;
import org.apache.http.client.protocol.ClientContext;
import org.apache.http.impl.auth.BasicScheme;
import org.apache.http.impl.client.BasicAuthCache;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.impl.conn.PoolingClientConnectionManager;
import org.apache.http.protocol.BasicHttpContext;

public class TomcatManager {
  private static final String MANAGER_CHARSET = "UTF-8";
  private String username;
  private URL url;
  private String password;
  private String charset;
  private boolean verbose;
  private DefaultHttpClient httpClient;
  private BasicHttpContext localContext;

  /** constructor */
  public TomcatManager(URL url, String username) {
    this(url, username, "");
  }
  public TomcatManager(URL url, String username, String password) {
    this(url, username, password, "ISO-8859-1");
  }
  public TomcatManager(URL url, String username, String password, String charset) {
    this(url, username, password, charset, true);
  }
  public TomcatManager(URL url, String username, String password, String charset, boolean verbose) {
    this.url = url;
    this.username = username;
    this.password = password;
    this.charset = charset;
    this.verbose = verbose;

    // 创建网络请求相关的配置
    PoolingClientConnectionManager poolingClientConnectionManager = new PoolingClientConnectionManager();
    poolingClientConnectionManager.setMaxTotal(5);
    this.httpClient = new DefaultHttpClient(poolingClientConnectionManager);

    if (StringUtils.isNotEmpty(username)) {
      Credentials creds = new UsernamePasswordCredentials(username, password);

      String host = url.getHost();
      int port = url.getPort() > -1 ? url.getPort() : AuthScope.ANY_PORT;
      httpClient.getCredentialsProvider().setCredentials(new AuthScope(host, port), creds);

      AuthCache authCache = new BasicAuthCache();
      BasicScheme basicAuth = new BasicScheme();
      HttpHost targetHost = new HttpHost(url.getHost(), url.getPort(), url.getProtocol());
      authCache.put(targetHost, basicAuth);

      localContext = new BasicHttpContext();
      localContext.setAttribute(ClientContext.AUTH_CACHE, authCache);
    }
  }

  /** 根据指定的path部署并启动一个新的应用程序 */
  public TomcatManagerResponse deploy(String path, File war, boolean update) throws Exception {
    StringBuilder buffer = new StringBuilder("/deploy");
    buffer.append("?path=").append(URLEncoder.encode(path, charset));
    if (war != null) {
      buffer.append("&war=").append(URLEncoder.encode(war.toString(), charset));
    }
    if (update) {
      buffer.append("&update=true");
    }
    return invoke(buffer.toString());
  }

  /** 获取所有已部署的web应用程序的上下文路径。格式为path:status:sessions(活动会话数) */
  public TomcatManagerResponse list() throws Exception {
    StringBuilder buffer = new StringBuilder("/list");
    return invoke(buffer.toString());
  }

  /** 获取系统信息和JVM信息 */
  public TomcatManagerResponse serverinfo() throws Exception {
    StringBuilder buffer = new StringBuilder("/serverinfo");
    return invoke(buffer.toString());
  }

  /** 真正发送请求的方法 */
  private TomcatManagerResponse invoke(String path) throws Exception {
    HttpRequestBase httpRequestBase = new HttpGet(url + path);
    HttpResponse response = httpClient.execute(httpRequestBase, localContext);

    int statusCode = response.getStatusLine().getStatusCode();
    switch (statusCode) {
      case HttpStatus.SC_OK: // 200
      case HttpStatus.SC_CREATED: // 201
      case HttpStatus.SC_ACCEPTED: // 202
        break;
      case HttpStatus.SC_MOVED_PERMANENTLY: // 301
      case HttpStatus.SC_MOVED_TEMPORARILY: // 302
      case HttpStatus.SC_SEE_OTHER: // 303
      String redirectUrl = getRedirectUrl(response);
      this.url = new URL(redirectUrl);
      return invoke(path);
    }

    return new TomcatManagerResponse().setStatusCode(response.getStatusLine().getStatusCode())
        .setReasonPhrase(response.getStatusLine().getReasonPhrase())
        .setHttpResponseBody(IOUtils.toString(response.getEntity().getContent()));
  }

  /** 提取重定向URL */
  protected String getRedirectUrl(HttpResponse response) {
    Header locationHeader = response.getFirstHeader("Location");
    String locationField = locationHeader.getValue();
    // is it a relative Location or a full ?
    return locationField.startsWith("http") ? locationField : url.toString() + '/' + locationField;
  }
}

封装响应结果集

@Data
public class TomcatManagerResponse {
  private int statusCode;
  private String reasonPhrase;
  private String httpResponseBody;
}

测试远程部署

在测试之前请先在配置文件放通下面用户权限：

<role rolename="admin-gui"/>
<role rolename="admin-script"/>
<role rolename="manager-gui"/>
<role rolename="manager-script"/>
<role rolename="manager-jmx"/>
<role rolename="manager-status"/>
<user username="sqdyy" password="123456" roles="manager-gui,manager-script,manager-jmx,manager-status,admin-script,admin-gui"/>

下面是测试成功远程部署war包的代码：

import static org.testng.AssertJUnit.assertEquals;
import java.io.File;
import java.net.URL;
import org.testng.annotations.Test;

public class TestTomcatManager {

  @Test
  public void testDeploy() throws Exception {
    TomcatManager tm = new TomcatManager(new URL("http://localhost:8080/manager/text"), "sqdyy", "123456");
    File war = new File("E:\\tomcat\\simple-war-project-1.0-SNAPSHOT.war");
    TomcatManagerResponse response = tm.deploy("/simple-war-project-1.0-SNAPSHOT", war, true);
    System.out.println(response.getHttpResponseBody());
    assertEquals(200, response.getStatusCode());

    // output:
    // OK - Deployed application at context path /simple-war-project-1.0-SNAPSHOT
  }

  @Test
  public void testList() throws Exception {
    TomcatManager tm = new TomcatManager(new URL("http://localhost:8080/manager/text"), "sqdyy", "123456");
    TomcatManagerResponse response = tm.list();
    System.out.println(response.getHttpResponseBody());
    assertEquals(200, response.getStatusCode());

    // output:
    // OK - Listed applications for virtual host localhost
    // /:running:0:ROOT
    // /simple-war-project-1.0-SNAPSHOT:running:0:simple-war-project-1.0-SNAPSHOT
    // /examples:running:0:examples
    // /host-manager:running:0:host-manager
    // /manager:running:0:manager
    // /docs:running:0:docs
  }

  @Test
  public void testServerinfo() throws Exception {
    TomcatManager tm = new TomcatManager(new URL("http://localhost:8080/manager/text"), "sqdyy", "123456");
    TomcatManagerResponse response = tm.serverinfo();
    System.out.println(response.getHttpResponseBody());
    assertEquals(200, response.getStatusCode());

    // output:
    // OK - Server info
    // Tomcat Version: Apache Tomcat/7.0.82
    // OS Name: Windows 10
    // OS Version: 10.0
    // OS Architecture: amd64
    // JVM Version: 1.8.0_144-b01
    // JVM Vendor: Oracle Corporation
  }
}

参考资料

ManagerServlet 源码地址

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