File Storage NAS:Mount a file system on a Function Compute function

Limits

• A Function Compute function supports a maximum of five NAS mount targets in a single region.

• The local directories specified for the NAS mount targets in the function's runtime environment cannot conflict.

Configure a NAS file system

1. Log on to the Function Compute console. In the left-side navigation pane, choose Function Management > Functions.

2. In the top navigation bar, select a region. On the Functions page, click the target function.

3. On the function details page, select the Configuration tab and click Modify next to Advanced Settings. In the Advanced Settings panel, go to the Storage section, enable Mount NAS file system , configure the required settings, and then click Deploy.

   You can configure the NAS file system using either Automatic Configuration or Custom Configuration.

   Auto config

   The system automatically creates a general-purpose NAS file system named Alibaba-Fc-V3-Component-Generated, along with a VPC, vSwitch, and security group with the same name.

   When you use Automatic Configuration again in the same region, the system reuses the existing NAS file system and VPC configurations instead of creating new ones. For more information about pricing, see VPC billing and Billing of general-purpose NAS.

   Custom config

   You must manually select a NAS file system and configure its parameters, such as user, user group, and mount target.

   The following table describes key parameters.

   Parameter	Description	Example
   NAS	Select an existing NAS file system. To create a NAS file system, click Create NAS File System and create one in the File Storage console. Important Only NAS file systems that use the NFS protocol are supported. NAS file systems that use the SMB protocol are not supported.	01d394****
   User, User Group	Specify a custom user ID and user group ID. If unspecified, the configuration defaults to the root user: UID=0 and GID=0. For more information, see NAS users and user groups.	1
   Remote Directory	For a general-purpose NAS file system, this directory must start with /. For an extreme NAS file system, this directory must start with /share. If the specified directory does not exist on the remote NAS, Function Compute automatically creates it. The new directory will be owned by the user and user group you specified and will have 777 permissions. For more information, see Remote directory.	/
   Local directory of a function	We recommend using a subdirectory of /home , /mnt, /tmp, or /data. Note Do not use common Linux and Unix system directories or their subdirectories, such as /bin, /opt, /var, or /dev. Otherwise, the mount may fail. For more information, see Local function directory.	/mnt/nas

   Note

   • To share NAS resources across multiple functions, configure each function with the same user and user group.

   • Files written to NAS will have the same permissions as files created locally within the function.

Verify the mount

Prepare the function code to access NAS

After configuring the NAS file system, you can access it in your code using the local directory path you specified for the mount.

1. On the function details page, click the Code tab. Write your code in the code editor, and then click Deploy.

   This topic uses a Python event-driven function as an example. The code writes content to and reads content from the NAS file system.

   #!/usr/bin/env python
   # -*- coding: utf-8 -*-
   
   import random
   import subprocess
   import string
   import os
   
   def handler(event, context):
       # report file system disk space usage and check NAS mount target
       out, err=subprocess.Popen(['df', '-h'], stdout=subprocess.PIPE).communicate()
       print('disk: ' + str(out))
       lines = [ l.decode() for l in out.splitlines() if str(l).find(':') != -1 ]
       nas_dirs = [ x.split()[-1] for x in lines ]
       print('uid : ' + str(os.geteuid()))
       print('gid : ' + str(os.getgid()))
   
       for nas_dir in nas_dirs:
           sub_dir = randomString(16)
           file_name = randomString(6)+'.txt'
           new_dir = nas_dir + '/' + sub_dir + '/'
           print('test file: ' + new_dir + file_name)
           # Write to a NAS file.
           content = "NAS here I come"
           os.mkdir(new_dir)
           fw = open(new_dir + file_name, "w+")
           fw.write(content)
           fw.close()
           # Display the directory tree on the NAS mount
           for home, dirs, files in os.walk(nas_dir):
               level = home.replace(nas_dir, '').count(os.sep)
               indent = ' ' * 2 * (level)
               print('{}{}/'.format(indent, os.path.basename(home)))
               subindent = ' ' * 2 * (level + 1)
               for f in files:
                   print('{}{}'.format(subindent, f))
           # Read from a NAS file.
           f = open(new_dir + file_name, "r")
           print(f.readline())
           f.close()
       
       return 'success'
   
   def randomString(n):
       return ''.join(random.SystemRandom().choice(string.ascii_uppercase + string.digits) for _ in range(n))
     

Verify the result

1. After the code is deployed, click Test Function on the Code tab.

   After the execution is complete, you can view the results at the bottom of the Code tab. On the Log Output tab, you can see that the function successfully wrote to and read from the NAS file.

   C9JFL0.txt
   DCFIC887M7R74WYH/
   5CXI5H.txt
   H0630SH2QHPL9MHZ/
   EUV7ZA.txt
   H4UNM032L2TDLPPQ/
   YXDBPM.txt
   HYMF79FH11AYW66D/
   LU3WNG.txt
   Z3QNEH0MY0K3VM6G/
   9D3FM2.txt
   fc-1/
   modelscope-60c13a-model-download-func/
   NAS here I come
   FC Invoke End RequestId: 1-66878b18-16cd285c-27f5980efe23

2. (Optional) After the function runs, you can log on to the instance to view the files in the local function directory and confirm that they match the log output.

   1. On the function details page, click the Instance tab. In the Actions column of the target instance, click Connect to Instance.

      If no instances are running, click Test Function on the Code tab to run the function again and create an instance.

   2. After you log on to the instance, you can run commands to view the files in the configured local function directory.

      root@c-668b4cff-xxx:/code# cd /mnt/nas
      root@c-668b4cff-xxx:/mnt/nas# ls
      0Q0V5ZYWMW7SLUYV  BVT5FA0OV9ZLIZMU  DCFIC887M7R74WYH  F8I2CGH79QQGPZKC  HO63OSH2QHPL9MHZ  H4UNM032L2TDLPPQ  HYMF79FH11AYW66D  KEDRGMD67X64A6FD  Z3QNEH0MY0K3VM6G  fc-1  modelscope-60c13a-model-download-func
      root@c-668b4cff-xxx:/mnt/nas# cd ../
      root@c-668b4cff-xxx:/mnt# cd nas/Z3QNEH0MY0K3VM6G
      root@c-668b4cff-xxx:/mnt/nas/Z3QNEH0MY0K3VM6G# ls
      9D3FM2.txt
      root@c-668b4cff-xxx:/mnt/nas/Z3QNEH0MY0K3VM6G#

Related concepts

References

For more information about the scenarios for using NAS with Function Compute and the differences between storage types, see Select a function storage type.