File transfer YAML

The file transfer YAML file describes the steps to obtain and transfer information from a network device to be stored in the Netpickers configs git repository. The information can be anything, although the main purpose is to collect the configuration itself.

The root element of the yaml is the protocols key with names of individual protocols, and should contain at least the default key.

Any given protocol can have:

• initial_context: object to initialize (local) variables used to define in the following objects.The following variables are present in any given moment:
  • dst_ip
  • dst_file
  • dst_volume
  • username
  • password
  • secret
• initialize: array of commands to obtain the information and store it in the appropriate file
• finalize: array of commands to clean up (temporary files etc)
• errors: objects defining what exception to raise in case of a matching reply from the device
• transfers: an object of transfer name (i.e. scp, sftp) with an array of commands that define how to transfer information to Netpicker. The transfers are executed in the defined order one by one until the {dst_file} is created so that it can be consumed by the Netpicker API.

Here is a transfer example of sftp for f5_linux device:

sftp:                                          # the name is arbitrary but should be descriptive enough
- command: sftp {username}@{dst_ip}            # the first command to be send
  finally:                                     # execute this command at the end even in case of failure
    command: "bye"                             # the command
    method: send_command                       # what netmiko method to use
    kwargs:                                    # additional keyword arguments to issue with the method
      expect_string: '#'
  prompts:                                     # the reply from the command is being matched against these keys
    password: "{password}"                     # if password appeared -> emit the password
    onnected to:                               # if C/connected to -> issue the put command
      command: put {src_file} {dst_file}
      method: send_command
      kwargs:
        expect_string: "sftp>"
        read_timeout: 600

For devices that do not support any advanced file transfer, one can use a screen scraping command like this:

screen:
  - show-run: tmsh show running-config recursive

The show-run is a shortcut for

  - command: tmsh show running-config recursive
    method: save_command_output
    kwargs:
      filename: {dst_file}

The save_command_output is not a netmiko native method but as the name suggest it takes the cli response of the device and saves it under the filename.

To avoid repetitiveness, one should use anchors. If there is more than one protocol, but the protocols have similar transfer methodology, one can use inheritance like:

protocols:
  default:
    initial_context:
      src_file: /var/local/scf/exportedconfig

    initialize:
      - command: tmsh show running-config recursive > {src_file}

    ...

  ucs:
    extends: default
    overrides:
      initial_context:
        src_file: /var/local/ncm.ucs

      initialize:
        - command: tmsh save /sys ucs {src_file}

In here, the ucs protocol will use the same steps as the default protocol but with overridden initial_context and initialize block.