remingtonc/gnmi-python-tutorial

Quick gNMI Python tutorial

gnmi-python-tutorial

Quick gNMI Python tutorial

Installation

git clone --recursive https://github.com/remingtonc/gnmi-python-tutorial
# Use your favorite Python dep handling
# with requirements.txt, or with pipenv...
pipenv install

YANG

We're using pyang to parse the YANG modules and determine what data we want to use in gNMI.

cd industry-models/vendor/cisco/xr/701
# Let's say we want openconfig-interfaces...
pyang -f tree openconfig-interfaces.yang openconfig-if*.yang

gNMI

We're using cisco-gnmi (cisco-ie/cisco-gnmi-python) - the class documentation and README in the repository has usage details.

(gnmi-python-tutorial) [gnmi-python-tutorial] python
Python 3.7.5 (default, Nov  1 2019, 02:16:32)
[Clang 11.0.0 (clang-1100.0.33.8)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> from cisco_gnmi import ClientBuilder
>>>

Loading Message from File

We can use the textual format for protobufs which is easy to write and directly load them in as messages to use with the client.

(gnmi-python-tutorial) [gnmi-python-tutorial] python
Python 3.7.5 (default, Nov  1 2019, 02:16:32)
[Clang 11.0.0 (clang-1100.0.33.8)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> from google.protobuf import text_format
>>> from cisco_gnmi import proto
>>> get_msg = proto.gnmi_pb2.GetRequest()
>>> proto_filename = 'cheating/get_interfaces.proto.txt'
>>> with open(proto_filename, 'r') as proto_fd:
...   proto_text = proto_fd.read()
...
>>> text_format.Merge(proto_text, get_msg)
path {
  elem {
    name: "interfaces"
  }
  elem {
    name: "interface"
  }
}
type: STATE
encoding: JSON_IETF
>>>