Embedded pyATS File Transfer Server

The embedded file transfer server allows a server to be launched automatically with any pyATS job run. This enables file transfer with devices for the duration of a run, with support for FTP, TFTP, SCP and HTTP. The FileServer class uses the device.spawn.pid process ID to lookup the local IP address which is reachable by devices in the testbed. Altnernatively, you can specify the subnet argument to find the correct network interface and local IP address. Once found, the testbed will be updated with the accurate server address, and launch a process with file server to listen on that interface with a random port. The SCP protocol just gathers the relevant information to add to the testbed and enable easy SCP copying with a device, but does not start any other processes.

When an file server is started, it will auto generate random credentials. These are only used for the duration of the run, after which they are lost. They are also entirely unrelated to user credentials, keeping user credentials secure.

The FileServer class and related Easypy Plugin are found in the genie.libs.filetransferutils package, and the plugin will be automatically run with every pyATS run as long as it is installed.

Using the Plugin

To start a file transfer server using the Easypy Plugin, the server must be defined in the testbed YAML file with dynamic: true, as well as some other information.

testbed:
  servers:
    myftpserver:
      dynamic: true
      protocol: ftp
      subnet: 10.0.0.0/8  # Optional
      path: /path/to/root/dir

Additional information can be defined for dynamic servers:

• dynamic: true allows the file transfer server plugin to identify it as a server to be started.

• protocol is one of ftp, tftp, or scp. The default is ftp.

• subnet is how the FileServer can identify which interface faces the testbed network so that the devices will be able to connect and copy files. This can also be defined in Configuration. (optional)

• path is the root directory being served by a FTP or TFTP server. The default is /

Once a server is started by the plugin, copy commands can just reference it by name. An example using a Genie API:

uut.api.copy_to_device(protocol='ftp',
                       server='myftpserver',
                       remote_path='myimage.bin',
                       local_path='flash:/‘)

Using as a context manager

A FileServer can also be used as a context manager if not defined in the testbed. It will only last for the duration of the context block, but can also add itself to the testbed for discovery by various copy APIs during that time.

from genie.libs.filetransferutils import FileServer
with FileServer(protocol='ftp',
                path='/path/to/root/dir',
                testbed=testbed,
                name='mycontextserver') as fs:
    uut.api.copy_to_device(protocol='ftp',
                           server='mycontextserver',
                           remote_path='myimage.bin',
                           local_path='flash:/‘)

Caveats

• Devices may not support copying to a non-standard port. The default port can be used by defining the port value of the server as well in the testbed YAML with the default port 69 for TFTP. However this port must be available for this to work, or the plugin will fail and the job will not execute.