[大数据]hadoop学习之WebHDFS (REST API)

官网永远是学习最好的地方

https://hadoop.apache.org/docs/r3.2.2/hadoop-yarn/hadoop-yarn-site/FairScheduler.html

?为什么要用rest api呢? 使用这个之前我们是如何操作hdfs上的文件的？

通过fs地址 和filesysterm，

现在webHdfs这个明显好用。。。

直接开搞。两种方式 一种是shell脚本 一种是java代码。

webhdfs已经开启?

?rest 端口为14000

集群为cdh 安装了kerberos的认证。

shell版本

[devuser@worker01 /data/cc_test/web]$ kinit hdfs 
Password for hdfs@CDH.COM: 
[devuser@worker01 /data/cc_test/web]$ klist
Ticket cache: FILE:/tmp/krb5cc_1000
Default principal: hdfs@CDH.COM

Valid starting       Expires              Service principal
2021-07-26T15:51:03  2021-07-27T15:51:03  krbtgt/CDH.COM@CDH.COM
	renew until 2021-08-02T15:51:03
[devuser@worker01 /data/cc_test/web]$ curl --negotiate -u : http://node03.data.com:14000/webhdfs/v1/?op=liststatus
{"FileStatuses":{"FileStatus":[{"pathSuffix":"data","type":"DIRECTORY","length":0,"owner":"hive","group":"hive","permission":"755","accessTime":0,"modificationTime":1627024265890,"blockSize":0,"replication":0},{"pathSuffix":"dolphinscheduler","type":"DIRECTORY","length":0,"owner":"dolphinscheduler","group":"dolphinscheduler","permission":"755","accessTime":0,"modificationTime":1606204815466,"blockSize":0,"replication":0},{"pathSuffix":"dolphinscheduler_xxx","type":"DIRECTORY","length":0,"owner":"dolphinscheduler","group":"dolphinscheduler","permission":"755","accessTime":0,"modificationTime":1604988539901,"blockSize":0,"replication":0},{"pathSuffix":"hbase","type":"DIRECTORY","length":0,"owner":"hbase","group":"hbase","permission":"755","accessTime":0,"modificationTime":1626160944859,"blockSize":0,"replication":0},{"pathSuffix":"streamx","type":"DIRECTORY","length":0,"owner":"devuser","group":"devuser","permission":"777","accessTime":0,"modificationTime":1624874177497,"blockSize":0,"replication":0},{"pathSuffix":"system","type":"DIRECTORY","length":0,"owner":"hdfs","group":"supergroup","permission":"755","accessTime":0,"modificationTime":1618555718143,"blockSize":0,"replication":0},{"pathSuffix":"tmp","type":"DIRECTORY","length":0,"owner":"hdfs","group":"supergroup","permission":"1777","accessTime":0,"modificationTime":1622450280651,"blockSize":0,"replication":0},{"pathSuffix":"user","type":"DIRECTORY","length":0,"owner":"hdfs","group":"supergroup","permission":"755","accessTime":0,"modificationTime":1611304943508,"blockSize":0,"replication":0}]}}
[devuser@worker01 /data/cc_test/web]$ 

java代码版本

import cn.hutool.core.lang.Console;
import cn.hutool.http.HttpUtil;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.security.UserGroupInformation;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.util.Properties;

public class downloadUtil {
    private static Logger logger=LoggerFactory.getLogger(downloadUtil.class);

    private  static  String listStatus_url="http://node03.data.com:14000/webhdfs/v1/?op=liststatus";
    public static void main(String[] args) {
        kerberos_auth(null);
        String result1= HttpUtil.get(listStatus_url);
        Console.log(result1);
    }

    private static void kerberos_auth(Properties prop){
        if (System.getProperty("os.name").toLowerCase().contains("windows")) {
            try {
                String krb5FilePath = "C:\\Users\\coder\\Desktop\\kerberos\\krb5.ini";
                String krb5KeyTabPath = "C:\\Users\\coder\\Desktop\\kerberos\\hive.keytab";
                String krbPrincipal = "hive@CDH.COM";
                // System.setProperty("java.security.krb5.conf", krb5Conf);
                System.setProperty("java.security.krb5.conf", krb5FilePath);
                System.setProperty("sun.security.krb5.debug", "true");
                Configuration configuration = new Configuration();
                configuration.set("hadoop.security.authentication", "Kerberos");
                configuration.set("keytab.file", krb5KeyTabPath);
                configuration.set("kerberos.principal", krbPrincipal);
                UserGroupInformation.setConfiguration(configuration);
                UserGroupInformation.loginUserFromKeytab(krbPrincipal, krb5KeyTabPath);
            } catch (IOException e) {
                logger.error("kerberos login异常 : {}", e.getMessage());
            }
        }else {
            try {
                String hive_keytable = prop.getProperty("hive_keytable");
                String hive_principal= prop.getProperty("hive_principal");
                logger.info("验证kerberos，hive_principal={},hive_keytable={}",hive_principal,hive_keytable);
                UserGroupInformation.loginUserFromKeytab(hive_principal, hive_keytable);
            } catch (IOException e) {
                logger.error("kerberos login异常 : {}", e.getMessage());
            }
        }
    }

}

打印日志

{
  "FileStatuses": {
    "FileStatus": [
      {
        "pathSuffix": "data",
        "type": "DIRECTORY",
        "length": 0,
        "owner": "hive",
        "group": "hive",
        "permission": "755",
        "accessTime": 0,
        "modificationTime": 1627024265890,
        "blockSize": 0,
        "replication": 0
      },
      {
        "pathSuffix": "dolphinscheduler",
        "type": "DIRECTORY",
        "length": 0,
        "owner": "dolphinscheduler",
        "group": "dolphinscheduler",
        "permission": "755",
        "accessTime": 0,
        "modificationTime": 1606204815466,
        "blockSize": 0,
        "replication": 0
      },
      {
        "pathSuffix": "dolphinscheduler_xxx",
        "type": "DIRECTORY",
        "length": 0,
        "owner": "dolphinscheduler",
        "group": "dolphinscheduler",
        "permission": "755",
        "accessTime": 0,
        "modificationTime": 1604988539901,
        "blockSize": 0,
        "replication": 0
      },
      {
        "pathSuffix": "hbase",
        "type": "DIRECTORY",
        "length": 0,
        "owner": "hbase",
        "group": "hbase",
        "permission": "755",
        "accessTime": 0,
        "modificationTime": 1626160944859,
        "blockSize": 0,
        "replication": 0
      },
      {
        "pathSuffix": "streamx",
        "type": "DIRECTORY",
        "length": 0,
        "owner": "devuser",
        "group": "devuser",
        "permission": "777",
        "accessTime": 0,
        "modificationTime": 1624874177497,
        "blockSize": 0,
        "replication": 0
      },
      {
        "pathSuffix": "system",
        "type": "DIRECTORY",
        "length": 0,
        "owner": "hdfs",
        "group": "supergroup",
        "permission": "755",
        "accessTime": 0,
        "modificationTime": 1618555718143,
        "blockSize": 0,
        "replication": 0
      },
      {
        "pathSuffix": "tmp",
        "type": "DIRECTORY",
        "length": 0,
        "owner": "hdfs",
        "group": "supergroup",
        "permission": "1777",
        "accessTime": 0,
        "modificationTime": 1622450280651,
        "blockSize": 0,
        "replication": 0
      },
      {
        "pathSuffix": "user",
        "type": "DIRECTORY",
        "length": 0,
        "owner": "hdfs",
        "group": "supergroup",
        "permission": "755",
        "accessTime": 0,
        "modificationTime": 1611304943508,
        "blockSize": 0,
        "replication": 0
      }
    ]
  }
}