Object Storage Service:Advanced configurations

Configure the account information

When you use ossfs to access Object Storage Service (OSS) buckets, you must configure your account information, including your AccessKey ID and AccessKey secret. The account information must be written to the account configuration file in the $bucket_name:$access_key_id:$access_key_secret format. ossfs obtains the account information from the account configuration file.

Use instance RAM roles

In Elastic Compute Service (ECS), you can use ossfs based on instance Resource Access Management (RAM) roles. You can attach a RAM role to an ECS instance to access OSS from the instance by using temporary credentials that are obtained from Security Token Service (STS). STS temporary credentials are automatically generated and updated. Applications can obtain the STS temporary credentials by using the instance metadata URL. The RAM role helps protect the security of your AccessKey pair and facilitates fine-grained permission control and management. For more information about instance RAM roles, see Overview.

The following section describes how to use ossfs by using the EcsRamRoleOssTest instance RAM role:

1. Create a RAM role named EcsRamRoleOssTest.
   For more information, see Step 1: Create an instance RAM role.
2. Grant the RAM role permissions to access OSS resources.
   For more information, see Grant permissions to a RAM role. In this example, the RAM role is granted the AliyunOSSReadOnlyAccess permission. You can specify a custom permission. For more information, see Create a custom policy.
3. Attach the RAM role to an ECS instance
   For more information, see Step 3: Attach the instance RAM role to an ECS instance.
4. Use ossfs based on the instance metadata URL.
   1. Log on to the ECS instance.
   2. Use ossfs. Add the -oram_role option.
      The bucket named Bucket1 located in the China (Hangzhou) region is used in the following example:

      ossfs bucket1 /tmp/ossfs -ourl=http://oss-cn-hangzhou.aliyuncs.com -oram_role=http://100.100.100.200/latest/meta-data/ram/security-credentials/EcsRamRoleOssTest

Configure access permissions

Attach a specific directory

ossfs bucket:/prefix mount_point -ourl=endpoint

When you run this command, make sure that an object named ${prefix}/ exists in the bucket. You can run the stat command of ossutil to check whether the object exists.

ossfs bucket-ossfs-test:/folder /tmp/ossfs-folder -ourl=http://oss-cn-hangzhou.aliyuncs.com

Attach a directory on startup

1. Write the bucket name, AccessKey ID, and AccessKey secret to the /etc/passwd-ossfs file, and change the permission on the file to 640.
   For more information, see Installation.
2. Enable automatic mount on startup.
   Note The following examples show how to enable automatic mount on startup for common versions of Ubuntu and CentOS. For other versions, refer to the relevant documents to enable automatic mount on startup.

   • Enable automatic mount on startup by using the fstab file for Ubuntu 14.04 or later and CentOS 6.5 or later
     1. Add the following command to the /etc/fstab file:

        ossfs#bucket_name mount_point fuse _netdev,url=url,allow_other 0 0

     2. Save the /etc/fstab file. Run the mount -a command. If no errors are reported, the settings are correctly configured
     3. After you complete the preceding operations, automatic mount on startup is enabled in Ubuntu 14.04. For CentOS 6.5, you must also run the following command:

        chkconfig netfs on

   • Enable automatic mount on startup by using the script for CentOS 7.0 or later
     1. Create the ossfs file in the /etc/init.d/ directory, and copy the content of the template to this file. Replace your_xxx with your actual information.
     2. Run the following command to allow the ossfs script to be executed:

        chmod a+x /etc/init.d/ossfs

        After the preceding command is run, you can execute the script. If the content of the script is correct, the OSS bucket is attached to the specified directory.
     3. Run the following command to start the ossfs script as a service which is automatically enabled on startup:

        chkconfig ossfs on

     4. After you complete the preceding operations, automatic mount on startup is enabled for ossfs.

Start ossfs by using Supervisor

Supervisor is a universal process management program of Python. Supervisor can turn a general command-line process into a background daemon and monitor the process. Supervisor automatically restarts the process when the process stops unexpectedly. Perform the following steps to start ossfs by using Supervisor:

1. Run the following command to install Supervisor:
   • CentOS

     sudo yum install supervisor

   • Ubuntu

     sudo apt-get install supervisor

2. Create an ossfs startup script.
   1. Run the following command to create a start_ossfs.sh file:

      mkdir /home/user1/ossfs_scripts

   2. Write the following command to the startup script:

      vi /home/user1/ossfs_scripts/start_ossfs.sh

      The following sample code provides an example on how the content of the start_ossfs.sh file is displayed:

      # Remove the mount point.
      fusermount -u /mnt/ossfs
      # Mount the OSS bucket. You must use the -f parameter to run ossfs on the frontend. 
      exec ossfs bucket_name mount_point -ourl=endpoint -f

3. Edit the /etc/supervisor/supervisord.conf file.

   sudo vi /etc/supervisor/supervisord.conf

   Add the following content to the end of the file:

   [program:ossfs]
   command=bash /home/user1/ossfs_scripts/start_ossfs.sh
   logfile=/var/log/ossfs.log
   log_stdout=true
   log_stderr=true
   logfile_maxbytes=1MB
   logfile_backups=10

4. Run the following command to run Supervisor:

   supervisord

5. Check whether Supervisor runs as expected.
   1. Run the following command to view the Supervisor process:

      ps aux | grep supervisor

   2. Run the following command to view the ossfs process:

      ps aux | grep ossfs

   3. Run the following command to stop the ossfs process.
      Important Do not use the killall command. If you run the killall command, the command sends the SIGTERM signal to stop the ossfs process. In this case, Supervisor does not restart the ossfs process.

      kill -9 ossfs 

      After the ossfs process is stopped, Supervisor restarts the ossfs process.
   4. Run the following command to view the ossfs process:

      ps aux | grep ossfs

Enable debug logging