:Build an FTP site on an instance that runs Alibaba Cloud Linux 3

Step 1: Install vsftpd

1. Connect to a Linux instance.

   For more information, see Connection methods.

2. Run the following command to install vsftpd:

   dnf install -y vsftpd

   A command output similar to the following one indicates that vsftpd is installed:

   Installed:
     vsftpd-3.0.3-35.0.1.al8.x86_64
   
   Complete!

3. Run the following command to enable the FTP service to automatically start on system startup:

   systemctl enable vsftpd.service

4. Run the following command to start the FTP service:

   systemctl start vsftpd.service

   Note

   If the "Job for vsftpd.service failed because the control process exited with error code" error message appears when you run the preceding command, check whether the following issues occur. If the issues occur, troubleshoot the issues and then restart FTP.

   • If port 21 is in use, run the lsof -i:21 command to check whether a process is running on the port. If a process is running on the port, run the kill -9 <Process ID> command to terminate the process.

   • If the network environment does not support IPv6 addresses, run the vim /etc/vsftpd/vsftpd.conf command to change the value of listen_ipv6 from YES to NO.

   • When the media access control (MAC) address that is specified for the network interface controller (NIC) named eth0 in the /etc/sysconfig/network-scripts/ifcfg-eth0 configuration file does not match the actual MAC address of the NIC, run the ifconfig command to query the actual MAC address of the NIC. Then, run the vim /etc/sysconfig/network-scripts/ifcfg-eth0 command to add or modify the HWADDR=<Actual MAC address of the NIC> parameter for the NIC in the configuration file. An ifconfig command output similar to the following one is returned, which indicates the MAC address of the eth0 NIC.

     

5. Run the following command to query the listening port of the FTP service:

   netstat -antup | grep ftp

   A command output similar to the following one indicates that the FTP service starts and listens on port 21:

   [root@iZbp14h7n3cwipjln62**** ~]# netstat -antup | grep ftp
   tcp6       0      0 :::21                   :::*                    LISTEN      5870/vsftpd

   By default, local user mode is enabled. To use the FTP service, configure other parameters.

Step 2: Configure vsftpd

In this example, vsftpd is configured in passive and local user modes to ensure data security.

1. Run the following command to create a Linux user for the FTP service. In this example, the ftptest user is created.

   adduser ftptest

2. Run the following command to change the password of the ftptest user:

   passwd ftptest

   Enter and confirm the password as prompted.

   [root@iZbp14h7n3cwipjln62**** ~]# passwd ftptest
   Changing password for user ftptest.
   New password:
   Retype new password:
   passwd: all authentication tokens updated successfully.

   Note

   To ensure password security, the entered password characters are hidden by default.

3. Run the following command to create a file directory for the FTP service.

   In this example, the /var/ftp/test file directory is created.

   mkdir /var/ftp/test

4. Run the following command to create a test file.

   In this example, the testfile.txt test file is created. The test file is used to access the FTP server from an FTP client.

   touch /var/ftp/test/testfile.txt

5. Run the following command to change the owner of the /var/ftp/test directory to ftptest:

   chown -R ftptest:ftptest /var/ftp/test

6. Modify the vsftpd.conf configuration file.

   1. Run the following command to open the configuration file of vsftpd.

      If you installed vsftpd by running the apt install vsftpd command, the path of the configuration file is /etc/vsftpd.conf.

      vim /etc/vsftpd/vsftpd.conf

   2. Press the I key to enter the Insert mode.

   3. Enable passive mode for the FTP server.

      Configure the following parameters and use the default values for other parameters.

      Important

      When you modify or add information in the configuration file, pay attention to the format. For example, an extra space may cause the service to fail to restart.

      Modify the following parameters:

      #Deny anonymous users from logging on to the FTP server. 
      anonymous_enable=NO
      #Allow local users to log on to the FTP server. 
      local_enable=YES
      #Listen on IPv4 sockets. 
      listen=YES

      Add a number sign (#) at the beginning of the line to comment out the following parameter and disable listening on IPv6 sockets.

      #listen_ipv6=YES

      Add the following parameters to the end of the configuration file. Change the value of pasv_address to the public IP address of the FTP server.

      #Specify the directory of a local user after the local user logs on. 
      local_root=/var/ftp/test
      #Limit all users to the home directory after they log on. 
      chroot_local_user=YES
      #Use a list to specify exception users. Exception users are not limited to the home directory after they log on. 
      chroot_list_enable=YES
      #Specify a file to store the list of exception users. 
      chroot_list_file=/etc/vsftpd/chroot_list
      #Enable passive mode. 
      pasv_enable=YES
      allow_writeable_chroot=YES
      #Enter the public IP address of the Linux instance used in this topic. 
      pasv_address=<Public IP address of the FTP server>
      #Specify the lowest possible port sent to the FTP clients for passive mode connections. 
      We recommend that you use ports in a high number range, such as 50000 to 50010. These ports provide more secure access to the FTP server. 
      pasv_min_port=50000
      #Specify the highest possible port sent to the FTP clients for passive mode connections 
      pasv_max_port=50010

      For information about more parameters, see vsftpd configuration file and parameters.

   4. Press the Esc key to exit the Insert mode. Enter :wq and press the Enter key to save and close the file.

7. Create the chroot_list file, and write the list of exception users to the file.

   Important

   If exception users do not exist, you must create the chroot_list file and leave the file empty.

   1. Run the following command to create the chroot_list file:

      vim /etc/vsftpd/chroot_list

   2. Press the I key to enter the Insert mode.

   3. Enter the list of exception users. Exception users are not limited to the home directory and have access to other directories.

   4. Press the Esc key to exit the Insert mode. Enter :wq and press the Enter key to save and close the file.

8. Run the following command to restart vsftpd:

   systemctl restart vsftpd.service

Step 3: Configure security groups

Step 4: Check whether you can access the FTP server from an FTP client

You can use FTP clients, Windows command-line tools, or browsers to check whether the FTP server is reachable. In this example, an on-premises host that runs a Windows Server 2012 R2 64-bit operating system is used as an FTP client to describe how to access the FTP server.

1. On the on-premises host, open File Explorer.

2. In the address bar, enter ftp://<Public IP address of the FTP server>:<FTP port>. In this example, the public IP address of the Linux instance is used. Example: ftp://121.43.XX.XX:21.

   Note

   If you cannot access the FTP site, perform the following operations:

   • Check whether port 21 is correctly configured in the security groups. For more information, see the Step 3: Configure security groups section of this topic.

   • Check whether the vsftpd.conf file is correctly configured. For more information, see the Modify the vsftpd.conf configuration file step in this topic.

   • Check whether a firewall is enabled on the on-premises host.

3. In the Log on as dialog box, enter the FTP username and password that you configured and then click Logon.

   After you log on to the FTP server, you can view the files in the specified directory on the FTP server. For example, you can view the test file named testfile.txt.