Updated on 2024-08-10 GMT+08:00

HTTP REST API Introduction

Function Description

Users can use the application programming interface (API) of Representational State Transfer (REST) to create, read and write, append, and delete files. For details of the REST API, see the following official guidelines:

http://hadoop.apache.org/docs/r3.1.1/hadoop-project-dist/hadoop-hdfs/WebHDFS.html.

Preparing Running Environment

  1. Install the client. Install the client on the node. For example, install the client in the /opt/client directory.

    1. Run the following command to for the user authentication. In the command, the hdfs is taken as an example and can be defined by users.
      kinit hdfs

      The validity duration of kinit authentication is 24 hours. After 24 hours, you need to re-authenticate the sample with the kinit to restart the sample.

    2. Prepare files testFile and testFileAppend and write content 'Hello, webhdfs user!' and 'Welcome back to webhdfs!'. Run the following command to prepare testFile and testFileAppend files:

      touch testFile

      vi testFile

      Hello, webhdfs user!

      touch testFileAppend

      vi testFileAppend

      Welcome back to webhdfs!

  2. The MRS cluster supports only the HTTPS access by default. If access by using the HTTPS service, perform 3. If access by using the HTTP service, perform 4.
  3. HTTPS-based access is different from HTTP-based access. When you access HDFS using HTTPS, you must ensure that the SSL protocol supported by the curl command is supported by the cluster because SSL security encryption is used. If the cluster does not support the SSL protocol, change the SSL protocol in the cluster. For example, if the Curl command only supports the TLSv1 protocol, modify the protocol configuration performing following measures:

    Log in to FusionInsight Manager and choose Cluster > Name of the desired cluster > Services > HDFS > Configurations > All Configurations. Type hadoop.ssl.enabled.protocols in the research box, check whether the parameter value contains TLSv1. If the parameter value does not contain TLSv1, add TLSv1 in the hadoop.ssl.enabled.protocols configuration item, and clear the value of ssl.server.exclude.cipher.list. Otherwise, HDFS cannot be accessed by using HTTPS. Then click Save and click More > Restart Service to restart the HDFS service.

    TLSv1 has security vulnerabilities. Exercise caution when using it.

  4. Log in to the FusionInsight Manager portal, choose Cluster > Name of the desired cluster > Services > HDFS > Configurations > All Configurations. Type dfs.http.policy in the research box, select HTTP_AND_HTTPS, click Save, and select More >Restart Service to restart the HDFS service.

Procedure

  1. Log in to the FusionInsight Manager portal, click Cluster > Name of the desired cluster > Services, and then select HDFS. The HDFS page is displayed.

    Because webhdfs is accessed through HTTP/HTTPS, you need to obtain the IP address of the active NameNode and the HTTP/HTTPS port.

    1. Click Instance, and in HDFS Instances page, view the host name and IP address of the active NameNode.
    2. Click Configurations, and in HDFS Service Configuration page, find namenode.https.port (9870) and namenode.https.port (9871).

  2. Create a directory by referring to the following link:

    http://hadoop.apache.org/docs/r3.1.1/hadoop-project-dist/hadoop-hdfs/WebHDFS.html#Make_a_Directory

    Click the link, Figure 1 is displayed:

    Figure 1 Example code of creating a directory

    Go to the /opt/client directory, the installation directory of the client, and create the huawei directory.

    1. Run the following command to check whether the huawei directory exists in the current path.

      hdfs dfs -ls /

      The running results are as follows:

      linux1:/opt/client # hdfs dfs -ls /
      16/04/22 16:10:02 INFO hdfs.PeerCache: SocketCache disabled.
      Found 7 items
      -rw-r--r--   3 hdfs   supergroup          0 2016-04-20 18:03 /PRE_CREATE_DIR.SUCCESS
      drwxr-x---   - flume  hadoop              0 2016-04-20 18:02 /flume
      drwx------   - hbase  hadoop              0 2016-04-22 15:19 /hbase
      drwxrwxrwx   - mapred hadoop              0 2016-04-20 18:02 /mr-history
      drwxrwxrwx   - spark  supergroup          0 2016-04-22 15:19 /sparkJobHistory
      drwxrwxrwx   - hdfs   hadoop              0 2016-04-22 14:51 /tmp
      drwxrwxrwx   - hdfs   hadoop              0 2016-04-22 14:50 /user

      The huawei directory does not exist in the current path.

    2. Run the command in Figure 1 that is named with huawei. Replace the <HOST> and <PORT>in the command with the host name or IP address and port number that are obtained in 1. Type the huawei as the directory in the <PATH>.

      The <HOST> can be replaced by the host name or IP address. It is noted that the port of HTTP is different from the port of HTTPS.

      • Run the following command to access HTTP:
        linux1:/opt/client # curl -i -X PUT --negotiate -u: "http://linux1:9870/webhdfs/v1/huawei?op=MKDIRS"

        In the command, the <HOST> is replaced by linux 1 and the <PORT> is replaced by 9870.

      • The running result is displayed as follows:
        HTTP/1.1 401 Authentication required
        Date: Thu, 05 May 2016 03:10:09 GMT
        Pragma: no-cache
        Date: Thu, 05 May 2016 03:10:09 GMT
        Pragma: no-cache
        X-Frame-Options: SAMEORIGIN
        WWW-Authenticate: Negotiate
        Set-Cookie: hadoop.auth=; Path=/; Expires=Thu, 01-Jan-1970 00:00:00 GMT; HttpOnly
        Content-Length: 0
        HTTP/1.1 200 OK
        Cache-Control: no-cache
        Expires: Thu, 05 May 2016 03:10:09 GMT
        Date: Thu, 05 May 2016 03:10:09 GMT
        Pragma: no-cache
        Expires: Thu, 05 May 2016 03:10:09 GMT
        Date: Thu, 05 May 2016 03:10:09 GMT
        Pragma: no-cache
        Content-Type: application/json
        X-Frame-Options: SAMEORIGIN
        WWW-Authenticate: Negotiate YGoGCSqGSIb3EgECAgIAb1swWaADAgEFoQMCAQ+iTTBLoAMCARKiRARCArhuv39Ttp6lhBlG3B0JAmFjv9weLp+SGFI+t2HSEHN6p4UVWKKy/kd9dKEgNMlyDu/o7ytzs0cqMxNsI69WbN5H
        Set-Cookie: hadoop.auth="u=hdfs&p=hdfs@<system domain name>&t=kerberos&e=1462453809395&s=wiRF4rdTWpm3tDST+a/Sy0lwgA4="; Path=/; Expires=Thu, 05-May-2016 13:10:09 GMT; HttpOnly
        Transfer-Encoding: chunked
        {"boolean":true}linux1:/opt/client # 

        If {"boolean":true} returns, the huawei directory is successfully created.

      • Run the following command to access HTTPS:
        linux1:/opt/client # curl -i -k -X PUT --negotiate -u: "https://10.120.172.109:9871/webhdfs/v1/huawei?op=MKDIRS"

        In the command, the <HOST> is replaced by IP address (10.120.172.109) and the <PORT> is replaced by 9871.

      • The running result is displayed as follows:
        HTTP/1.1 401 Authentication required
        Date: Fri, 22 Apr 2016 08:13:37 GMT
        Pragma: no-cache
        Date: Fri, 22 Apr 2016 08:13:37 GMT
        Pragma: no-cache
        X-Frame-Options: SAMEORIGIN
        WWW-Authenticate: Negotiate
        Set-Cookie: hadoop.auth=; Path=/; Expires=Thu, 01-Jan-1970 00:00:00 GMT; Secure; HttpOnly
        Content-Length: 0
        HTTP/1.1 200 OK
        Cache-Control: no-cache
        Expires: Fri, 22 Apr 2016 08:13:37 GMT
        Date: Fri, 22 Apr 2016 08:13:37 GMT
        Pragma: no-cache
        Expires: Fri, 22 Apr 2016 08:13:37 GMT
        Date: Fri, 22 Apr 2016 08:13:37 GMT
        Pragma: no-cache
        Content-Type: application/json
        X-Frame-Options: SAMEORIGIN
        WWW-Authenticate: Negotiate YGoGCSqGSIb3EgECAgIAb1swWaADAgEFoQMCAQ+iTTBLoAMCARKiRARCugB+yT3Y+z8YCRMYJHXF84o1cyCfJq157+NZN1gu7D7yhMULnjr+7BuUdEcZKewFR7uD+DRiMY3akg3OgU45xQ9R
        Set-Cookie: hadoop.auth="u=hdfs&p=hdfs@<system domain name>&t=kerberos&e=1461348817963&s=sh57G7iVccX/Aknoz410yJPTLHg="; Path=/; Expires=Fri, 22-Apr-2016 18:13:37 GMT; Secure; HttpOnly
        Transfer-Encoding: chunked
        
        {"boolean":true}linux1:/opt/client # 

        If {"boolean":true} returns, the huawei directory is successfully created.

    3. Run the following command to check the huawei directory in the path.
      linux1:/opt/client # hdfs dfs -ls /
      16/04/22 16:14:25 INFO hdfs.PeerCache: SocketCache disabled.
      Found 8 items
      -rw-r--r--   3 hdfs   supergroup          0 2016-04-20 18:03 /PRE_CREATE_DIR.SUCCESS
      drwxr-x---   - flume  hadoop              0 2016-04-20 18:02 /flume
      drwx------   - hbase  hadoop              0 2016-04-22 15:19 /hbase
      drwxr-xr-x   - hdfs  supergroup          0 2016-04-22 16:13 /huawei
      drwxrwxrwx   - mapred hadoop              0 2016-04-20 18:02 /mr-history
      drwxrwxrwx   - spark  supergroup          0 2016-04-22 16:12 /sparkJobHistory
      drwxrwxrwx   - hdfs   hadoop              0 2016-04-22 14:51 /tmp
      drwxrwxrwx   - hdfs   hadoop              0 2016-04-22 16:10 /user

  3. Create a command of the upload request to obtain the information about Location where the DataNode IP address is written in.

    • Run the following command to access HTTP:
      linux1:/opt/client # curl -i -X PUT --negotiate -u: "http://linux1:9870/webhdfs/v1/huawei/testHdfs?op=CREATE"
    • The running result is displayed as follows:
      HTTP/1.1 401 Authentication required
      Date: Thu, 05 May 2016 06:09:48 GMT
      Pragma: no-cache
      Date: Thu, 05 May 2016 06:09:48 GMT
      Pragma: no-cache
      X-Frame-Options: SAMEORIGIN
      WWW-Authenticate: Negotiate
      Set-Cookie: hadoop.auth=; Path=/; Expires=Thu, 01-Jan-1970 00:00:00 GMT; HttpOnly
      Content-Length: 0
      
      HTTP/1.1 307 TEMPORARY_REDIRECT
      Cache-Control: no-cache
      Expires: Thu, 05 May 2016 06:09:48 GMT
      Date: Thu, 05 May 2016 06:09:48 GMT
      Pragma: no-cache
      Expires: Thu, 05 May 2016 06:09:48 GMT
      Date: Thu, 05 May 2016 06:09:48 GMT
      Pragma: no-cache
      Content-Type: application/octet-stream
      X-Frame-Options: SAMEORIGIN
      WWW-Authenticate: Negotiate YGoGCSqGSIb3EgECAgIAb1swWaADAgEFoQMCAQ+iTTBLoAMCARKiRARCzQ6w+9pNzWCTJEdoU3z9xKEyg1JQNka0nYaB9TndvrL5S0neAoK2usnictTFnqIincAjwB6SnTtht8Q16WDlHJX/
      Set-Cookie: hadoop.auth="u=hdfs&p=hdfs@<system domain name>&t=kerberos&e=1462464588403&s=qry87vAyYzSn9VsS6Rm6vKLhKeU="; Path=/; Expires=Thu, 05-May-2016 16:09:48 GMT; HttpOnly
      Location: http://linux1:25010/webhdfs/v1/huawei/testHdfs?op=CREATE&delegation=HgAFYWRtaW4FYWRtaW4AigFUf4lZdIoBVKOV3XQOCBSyXvFAp92alcRs4j-KNulnN6wUoBJXRUJIREZTIGRlbGVnYXRpb24UMTAuMTIwLjE3Mi4xMDk6MjUwMDA&namenoderpcaddress=hacluster&overwrite=false
      Content-Length: 0
    • Run the following command to access HTTPS:
      linux1:/opt/client # curl -i -k -X PUT --negotiate -u: "https://linux1:25003/webhdfs/v1/huawei/testHdfs?op=CREATE"
    • The running result is displayed as follows:
      HTTP/1.1 401 Authentication required
      Date: Thu, 05 May 2016 03:46:18 GMT
      Pragma: no-cache
      Date: Thu, 05 May 2016 03:46:18 GMT
      Pragma: no-cache
      X-Frame-Options: SAMEORIGIN
      WWW-Authenticate: Negotiate
      Set-Cookie: hadoop.auth=; Path=/; Expires=Thu, 01-Jan-1970 00:00:00 GMT; Secure; HttpOnly
      Content-Length: 0
      
      HTTP/1.1 307 TEMPORARY_REDIRECT
      Cache-Control: no-cache
      Expires: Thu, 05 May 2016 03:46:18 GMT
      Date: Thu, 05 May 2016 03:46:18 GMT
      Pragma: no-cache
      Expires: Thu, 05 May 2016 03:46:18 GMT
      Date: Thu, 05 May 2016 03:46:18 GMT
      Pragma: no-cache
      Content-Type: application/octet-stream
      X-Frame-Options: SAMEORIGIN
      WWW-Authenticate: Negotiate YGoGCSqGSIb3EgECAgIAb1swWaADAgEFoQMCAQ+iTTBLoAMCARKiRARCZMYR8GGUkn7pPZaoOYZD5HxzLTRZ71angUHKubW2wC/18m9/OOZstGQ6M1wH2pGriipuCNsKIfwP93eO2Co0fQF3
      Set-Cookie: hadoop.auth="u=hdfs&p=hdfs@<system domain name>&t=kerberos&e=1462455978166&s=F4rXUwEevHZze3PR8TxkzcV7RQQ="; Path=/; Expires=Thu, 05-May-2016 13:46:18 GMT; Secure; HttpOnly
      Location: https://linux1:9865/webhdfs/v1/huawei/testHdfs?op=CREATE&delegation=HgAFYWRtaW4FYWRtaW4AigFUfwX3t4oBVKMSe7cCCBSFJTi9j7X64QwnSz59TGFPKFf7GhNTV0VCSERGUyBkZWxlZ2F0aW9uFDEwLjEyMC4xNzIuMTA5OjI1MDAw&namenoderpcaddress=hacluster&overwrite=false
      Content-Length: 0

  4. According to the Location information, create the testHdfs file in the /huawei/testHdfs file on the HDFS and upload the content in the local testFile file into the testHdfs file.

    • Run the following command to access HTTP:
      linux1:/opt/client # curl -i -X PUT -T testFile --negotiate -u: "http://linux1:9864/webhdfs/v1/huawei/testHdfs?op=CREATE&delegation=HgAFYWRtaW4FYWRtaW4AigFUf4lZdIoBVKOV3XQOCBSyXvFAp92alcRs4j-KNulnN6wUoBJXRUJIREZTIGRlbGVnYXRpb24UMTAuMTIwLjE3Mi4xMDk6MjUwMDA&namenoderpcaddress=hacluster&overwrite=false"
    • The running result is displayed as follows:
      HTTP/1.1 100 Continue
      HTTP/1.1 201 Created
      Location: hdfs://hacluster/huawei/testHdfs
      Content-Length: 0
      Connection: close
    • Run the following command to access HTTPS:
      linux1:/opt/client # curl -i -k -X PUT -T testFile --negotiate -u: "https://linux1:9865/webhdfs/v1/huawei/testHdfs?op=CREATE&delegation=HgAFYWRtaW4FYWRtaW4AigFUfwX3t4oBVKMSe7cCCBSFJTi9j7X64QwnSz59TGFPKFf7GhNTV0VCSERGUyBkZWxlZ2F0aW9uFDEwLjEyMC4xNzIuMTA5OjI1MDAw&namenoderpcaddress=hacluster&overwrite=false"
    • The running result is displayed as follows:
      HTTP/1.1 100 Continue
      HTTP/1.1 201 Created
      Location: hdfs://hacluster/huawei/testHdfs
      Content-Length: 0
      Connection: close

  5. Go to the /huawei/testHdfs directory and read the content of testHdfs file.

    • Run the following command to access HTTP:
      linux1:/opt/client # curl -L --negotiate -u: "http://linux1:9870/webhdfs/v1/huawei/testHdfs?op=OPEN"
    • The running result is displayed as follows:
      Hello, webhdfs user!
    • Run the following command to access HTTPS:
      linux1:/opt/client # curl -k -L --negotiate -u: "https://linux1:9871/webhdfs/v1/huawei/testHdfs?op=OPEN"
    • The running result is displayed as follows:
      Hello, webhdfs user!

  6. Create a command of the upload request to obtain the information about Location where the DataNode IP address of testHdfs file is written in.

    • Run the following command to access HTTP:
      linux1:/opt/client # curl -i -X POST --negotiate -u: "http://linux1:9870//webhdfs/v1/huawei/testHdfs?op=APPEND"
    • The running result is displayed as follows:
      HTTP/1.1 401 Authentication required
      Cache-Control: must-revalidate,no-cache,no-store
      Date: Thu, 05 May 2016 05:35:02 GMT
      Pragma: no-cache
      Date: Thu, 05 May 2016 05:35:02 GMT
      Pragma: no-cache
      Content-Type: text/html; charset=iso-8859-1
      X-Frame-Options: SAMEORIGIN
      WWW-Authenticate: Negotiate
      Set-Cookie: hadoop.auth=; Path=/; Expires=Thu, 01-Jan-1970 00:00:00 GMT; HttpOnly
      Content-Length: 1349
      
      HTTP/1.1 307 TEMPORARY_REDIRECT
      Cache-Control: no-cache
      Expires: Thu, 05 May 2016 05:35:02 GMT
      Date: Thu, 05 May 2016 05:35:02 GMT
      Pragma: no-cache
      Expires: Thu, 05 May 2016 05:35:02 GMT
      Date: Thu, 05 May 2016 05:35:02 GMT
      Pragma: no-cache
      Content-Type: application/octet-stream
      X-Frame-Options: SAMEORIGIN
      WWW-Authenticate: Negotiate YGoGCSqGSIb3EgECAgIAb1swWaADAgEFoQMCAQ+iTTBLoAMCARKiRARCTYvNX/2JMXhzsVPTw3Sluox6s/gEroHH980xMBkkYlCnO3W+0fM32c4/F98U5bl5dzgoolQoBvqq/EYXivvR12WX
      Set-Cookie: hadoop.auth="u=hdfs&p=hdfs@<system domain name>&t=kerberos&e=1462462502626&s=et1okVIOd7DWJ/LdhzNeS2wQEEY="; Path=/; Expires=Thu, 05-May-2016 15:35:02 GMT; HttpOnly
      Location: http://linux1:9864/webhdfs/v1/huawei/testHdfs?op=APPEND&delegation=HgAFYWRtaW4FYWRtaW4AigFUf2mGHooBVKN2Ch4KCBRzjM3jwSMlAowXb4dhqfKB5rT-8hJXRUJIREZTIGRlbGVnYXRpb24UMTAuMTIwLjE3Mi4xMDk6MjUwMDA&namenoderpcaddress=hacluster
      Content-Length: 0
    • Run the following command to access HTTPS:
      linux1:/opt/client # curl -i -k -X POST --negotiate -u: "https://linux1:9871/webhdfs/v1/huawei/testHdfs?op=APPEND"
    • The running result is displayed as follows:
      HTTP/1.1 401 Authentication required
      Cache-Control: must-revalidate,no-cache,no-store
      Date: Thu, 05 May 2016 05:20:41 GMT
      Pragma: no-cache
      Date: Thu, 05 May 2016 05:20:41 GMT
      Pragma: no-cache
      Content-Type: text/html; charset=iso-8859-1
      X-Frame-Options: SAMEORIGIN
      WWW-Authenticate: Negotiate
      Set-Cookie: hadoop.auth=; Path=/; Expires=Thu, 01-Jan-1970 00:00:00 GMT; Secure; HttpOnly
      Content-Length: 1349
      
      HTTP/1.1 307 TEMPORARY_REDIRECT
      Cache-Control: no-cache
      Expires: Thu, 05 May 2016 05:20:41 GMT
      Date: Thu, 05 May 2016 05:20:41 GMT
      Pragma: no-cache
      Expires: Thu, 05 May 2016 05:20:41 GMT
      Date: Thu, 05 May 2016 05:20:41 GMT
      Pragma: no-cache
      Content-Type: application/octet-stream
      X-Frame-Options: SAMEORIGIN
      WWW-Authenticate: Negotiate YGoGCSqGSIb3EgECAgIAb1swWaADAgEFoQMCAQ+iTTBLoAMCARKiRARCXgdjZuoxLHGtM1oyrPcXk95/Y869eMfXIQV5UdEwBZ0iQiYaOdf5+Vk7a7FezhmzCABOWYXPxEQPNugbZ/yD5VLT
      Set-Cookie: hadoop.auth="u=hdfs&p=hdfs@<system domain name>&t=kerberos&e=1462461641713&s=tGwwOH9scmnNtxPjlnu28SFtex0="; Path=/; Expires=Thu, 05-May-2016 15:20:41 GMT; Secure; HttpOnly
      Location: https://linux1:9865/webhdfs/v1/huawei/testHdfs?op=APPEND&delegation=HgAFYWRtaW4FYWRtaW4AigFUf1xi_4oBVKNo5v8HCBSE3Fg0f_EwtFKKlODKQSM2t32CjhNTV0VCSERGUyBkZWxlZ2F0aW9uFDEwLjEyMC4xNzIuMTA5OjI1MDAw&namenoderpcaddress=hacluster

  7. According to the Location information, add the content in the local testFileAppend file to the testHdfs file that is in the /huawei/testHdfs directory of HDFS.

    • Run the following command to access HTTP:
      linux1:/opt/client # curl -i -X POST -T testFileAppend --negotiate -u: "http://linux1:9864/webhdfs/v1/huawei/testHdfs?op=APPEND&delegation=HgAFYWRtaW4FYWRtaW4AigFUf2mGHooBVKN2Ch4KCBRzjM3jwSMlAowXb4dhqfKB5rT-8hJXRUJIREZTIGRlbGVnYXRpb24UMTAuMTIwLjE3Mi4xMDk6MjUwMDA&namenoderpcaddress=hacluster"
    • The running result is displayed as follows:
      HTTP/1.1 100 Continue
      HTTP/1.1 200 OK
      Content-Length: 0
      Connection: close
    • Run the following command to access HTTPS:
      linux1:/opt/client # curl -i -k -X POST -T testFileAppend --negotiate -u: "https://linux1:9865/webhdfs/v1/huawei/testHdfs?op=APPEND&delegation=HgAFYWRtaW4FYWRtaW4AigFUf1xi_4oBVKNo5v8HCBSE3Fg0f_EwtFKKlODKQSM2t32CjhNTV0VCSERGUyBkZWxlZ2F0aW9uFDEwLjEyMC4xNzIuMTA5OjI1MDAw&namenoderpcaddress=hacluster"
    • The running result is displayed as follows:
      HTTP/1.1 100 Continue
      HTTP/1.1 200 OK
      Content-Length: 0
      Connection: close

  8. Go to the /huawei/testHdfs directory and read all content in the testHdfs file.

    • Run the following command to access HTTP:
      linux1:/opt/client # curl -L --negotiate -u: "http://linux1:9870/webhdfs/v1/huawei/testHdfs?op=OPEN"
    • The running result is displayed as follows:
      Hello, webhdfs user!
      Welcome back to webhdfs!
    • Run the following command to access HTTPS:
      linux1:/opt/client # curl -k -L --negotiate -u: "https://linux1:9871/webhdfs/v1/huawei/testHdfs?op=OPEN"
    • The running result is displayed as follows:
      Hello, webhdfs user!
      Welcome back to webhdfs!

  9. List details of all directory and file information in the huawei directory of the HDFS.

    LISTSTATUS will return all child files and folders information in a single request.
    • Run the following command to access HTTP.
      linux1:/opt/client # curl --negotiate -u: "http://linux1:9870/webhdfs/v1/huawei/testHdfs?op=LISTSTATUS"
    • The result is displayed as follows:
      {"FileStatuses":{"FileStatus":[
      {"accessTime":1462425245595,"blockSize":134217728,"childrenNum":0,"fileId":17680,"group":"supergroup","length":70,"modificationTime":1462426678379,"owner":"hdfs","pathSuffix":"","permission":"755","replication":3,"storagePolicy":0,"type":"FILE"}
      ]}}
    • Run the following command to access HTTPS.
      linux1:/opt/client # curl -k --negotiate -u: "https://linux1:9871/webhdfs/v1/huawei/testHdfs?op=LISTSTATUS"
    • The result is displayed as follows:
      {"FileStatuses":{"FileStatus":[
      {"accessTime":1462425245595,"blockSize":134217728,"childrenNum":0,"fileId":17680,"group":"supergroup","length":70,"modificationTime":1462426678379,"owner":"hdfs","pathSuffix":"","permission":"755","replication":3,"storagePolicy":0,"type":"FILE"}
      ]}}
    LISTSTATUS along with size and startafter param will help in fetching the child files and folders information through multiple requests, thus avoiding the user interface from becoming slow when there is a large amount of child information to be fetched.
    • Run the following command to access HTTP.
      linux1:/opt/client # curl --negotiate -u: "http://linux1:9870/webhdfs/v1/huawei/?op=LISTSTATUS&startafter=sparkJobHistory&size=1"
    • The result is displayed as follows:
      {"FileStatuses":{"FileStatus":[
      {"accessTime":1462425245595,"blockSize":134217728,"childrenNum":0,"fileId":17680,"group":"supergroup","length":70,"modificationTime":1462426678379,"owner":"hdfs","pathSuffix":"testHdfs","permission":"755","replication":3,"storagePolicy":0,"type":"FILE"}
      ]}}
    • Run the following command to access HTTPS.
      linux1:/opt/client # curl -k --negotiate -u: "https://linux1:9871/webhdfs/v1/huawei/?op=LISTSTATUS&startafter=sparkJobHistory&size=1"
    • The result is displayed as follows:
      {"FileStatuses":{"FileStatus":[
      {"accessTime":1462425245595,"blockSize":134217728,"childrenNum":0,"fileId":17680,"group":"supergroup","length":70,"modificationTime":1462426678379,"owner":"hdfs","pathSuffix":"testHdfs","permission":"755","replication":3,"storagePolicy":0,"type":"FILE"}
      ]}}

  10. Delete the testHdfs file that is in the /huawei/testHdfs directory of HDFS.

    • Run the following command to access HTTP:
      linux1:/opt/client # curl -i -X DELETE  --negotiate -u: "http://linux1:9870/webhdfs/v1/huawei/testHdfs?op=DELETE"
    • The running result is displayed as follows:
      HTTP/1.1 401 Authentication required
      Date: Thu, 05 May 2016 05:54:37 GMT
      Pragma: no-cache
      Date: Thu, 05 May 2016 05:54:37 GMT
      Pragma: no-cache
      X-Frame-Options: SAMEORIGIN
      WWW-Authenticate: Negotiate
      Set-Cookie: hadoop.auth=; Path=/; Expires=Thu, 01-Jan-1970 00:00:00 GMT; HttpOnly
      Content-Length: 0
      HTTP/1.1 200 OK
      Cache-Control: no-cache
      Expires: Thu, 05 May 2016 05:54:37 GMT
      Date: Thu, 05 May 2016 05:54:37 GMT
      Pragma: no-cache
      Expires: Thu, 05 May 2016 05:54:37 GMT
      Date: Thu, 05 May 2016 05:54:37 GMT
      Pragma: no-cache
      Content-Type: application/json
      X-Frame-Options: SAMEORIGIN
      WWW-Authenticate: Negotiate YGoGCSqGSIb3EgECAgIAb1swWaADAgEFoQMCAQ+iTTBLoAMCARKiRARC9k0/v6Ed8VlUBy3kuT0b4RkqkNMCrDevsLGQOUQRORkzWI3Wu+XLJUMKlmZaWpP+bPzpx8O2Od81mLBgdi8sOkLw
      Set-Cookie: hadoop.auth="u=hdfs&p=hdfs@<system domain name>&t=kerberos&e=1462463677153&s=Pwxe5UIqaULjFb9R6ZwlSX85GoI="; Path=/; Expires=Thu, 05-May-2016 15:54:37 GMT; HttpOnly
      Transfer-Encoding: chunked
      {"boolean":true}linux1:/opt/client # 
    • Run the following command to access HTTPS:
      linux1:/opt/client # curl -i -k -X DELETE --negotiate -u: "https://linux1:9871/webhdfs/v1/huawei/testHdfs?op=DELETE"
    • The running result is displayed as follows:
      HTTP/1.1 401 Authentication required
      Date: Thu, 05 May 2016 06:20:10 GMT
      Pragma: no-cache
      Date: Thu, 05 May 2016 06:20:10 GMT
      Pragma: no-cache
      X-Frame-Options: SAMEORIGIN
      WWW-Authenticate: Negotiate
      Set-Cookie: hadoop.auth=; Path=/; Expires=Thu, 01-Jan-1970 00:00:00 GMT; Secure; HttpOnly
      Content-Length: 0
      HTTP/1.1 200 OK
      Cache-Control: no-cache
      Expires: Thu, 05 May 2016 06:20:10 GMT
      Date: Thu, 05 May 2016 06:20:10 GMT
      Pragma: no-cache
      Expires: Thu, 05 May 2016 06:20:10 GMT
      Date: Thu, 05 May 2016 06:20:10 GMT
      Pragma: no-cache
      Content-Type: application/json
      X-Frame-Options: SAMEORIGIN
      WWW-Authenticate: Negotiate YGoGCSqGSIb3EgECAgIAb1swWaADAgEFoQMCAQ+iTTBLoAMCARKiRARCLY5vrVmgsiH2VWRypc30iZGffRUf4nXNaHCWni3TIDUOTl+S+hfjatSbo/+uayQI/6k9jAfaJrvFIfxqppFtofpp
      Set-Cookie: hadoop.auth="u=hdfs&p=hdfs@<system domain name>&t=kerberos&e=1462465210180&s=KGd2SbH/EUSaaeVKCb5zPzGBRKo="; Path=/; Expires=Thu, 05-May-2016 16:20:10 GMT; Secure; HttpOnly
      Transfer-Encoding: chunked
      {"boolean":true}linux1:/opt/client #

The Key Management Server (KMS) uses the HTTP REST API to provide key management services for external systems. For details about the API, see http://hadoop.apache.org/docs/r3.1.1/hadoop-kms/index.html.

As REST API interface has done security hardening to prevent script injection attack. Through REST API interface, it cannot create directory and file name which contain those key words "<script ", "<iframe", "<frame", "javascript:".