The YANG Development Kit (YDK) is a Software Development Kit that provides API's that are modeled in YANG. The main goal of YDK is to reduce the learning curve of YANG data models by expressing the model semantics in an API and abstracting protocol/encoding details. YDK is composed of a core package that defines services and providers, plus one or more module bundles that are based on YANG models.

Please see the release notes and documentation for details on some backward incompatible changes introduced as part of the 0.6.0 release.

A docker image is automatically built with the latest ydk-py installed. This be used to run ydk-py without installing anything natively on your machine.

To use the docker image, install docker on your system and run the below command. See the docker documentation for more details:

.. code-block:: sh

docker run -it ydkdev/ydk-py

Note: libssh 0.8.0 and later does not support separate threading library, which is required for YDK. Please use libssh-0.7.x.

Ubuntu (Debian-based)

The following packages must be present in your system before installing YDK-Py:

.. code-block:: sh

$ sudo apt-get update > /dev/null $ sudo add-apt-repository ppa:ubuntu-toolchain-r/test -y $ sudo apt-get install gdebi-core python3-dev python-dev libtool-bin

# Upgrade compiler to gcc 5.* $ sudo apt-get install gcc-5 g++-5 -y > /dev/null $ sudo ln -sf /usr/bin/gcc-5 /usr/bin/cc $ sudo ln -sf /usr/bin/g++-5 /usr/bin/c++

Download and install YDK core library - libydk. You can install the library using prebuilt debian packages for Xenial and Bionic LTS distributions. For other Ubuntu distributions it is recommended to build core library from source.

For Xenial (Ubuntu 16.04.4):

wget https://devhub.cisco.com/artifactory/debian-ydk/0.8.0/xenial/libydk_0.8.0-1_amd64.deb
sudo gdebi libydk_0.8.0-1_amd64.deb

For Bionic (Ubuntu 18.04.1):

wget https://devhub.cisco.com/artifactory/debian-ydk/0.8.0/bionic/libydk_0.8.0-1_amd64.deb
sudo gdebi libydk_0.8.0-1_amd64.deb

Centos (Fedora-based)

The following packages must be present in your system before installing YDK-Py. Currently, only Centos7/RHEL7 are known to work:

.. code-block:: sh

# The below may not be required on Fedora27 $ sudo yum install epel-release $ sudo yum install libssh-devel gcc-c++ python-devel

# Upgrade compiler to gcc 5.* $ sudo yum install centos-release-scl -y > /dev/null $ sudo yum install devtoolset-4-gcc* -y > /dev/null $ sudo ln -sf /opt/rh/devtoolset-4/root/usr/bin/gcc /usr/bin/cc $ sudo ln -sf /opt/rh/devtoolset-4/root/usr/bin/g++ /usr/bin/c++

# Install YDK core library $ sudo yum install https://devhub.cisco.com/artifactory/rpm-ydk/0.8.0/libydk-0.8.0-1.x86_64.rpm

It is required to install Xcode command line tools, homebrew and the following homebrew packages on your system before installing YDK-Py.

You can download the latest python package from here. Please do not use the homebrew version of python as it causes issues with installing ydk packages. Please execute brew rm python python3 to remove any homebrew python packages:

.. code-block:: sh

$ xcode-select --install $ /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)" $ brew install pkg-config libssh xml2 libxml2 curl pcre cmake pybind11

$ curl -O https://devhub.cisco.com/artifactory/osx-ydk/0.8.0/libydk-0.8.0-Darwin.pkg $ sudo installer -pkg libydk-0.8.0-Darwin.pkg -target /

Currently, YDK-Py from release 0.6.0 onwards is not supported on Windows.

Both Python 2 and 3 are supported. At least Python 2.7 or Python 3.4 must be installed in your system.

In order to enable YDK support for gNMI protocol, which is optional, the following third party software must be installed prior to gNMI YDK component installation.

$ wget https://github.com/google/protobuf/releases/download/v3.5.0/protobuf-cpp-3.5.0.zip
$ unzip protobuf-cpp-3.5.0.zip
$ cd protobuf-3.5.0
$ ./configure
$ make
$ make check
$ sudo make install
$ sudo ldconfig

$ git clone -b v1.9.1 https://github.com/grpc/grpc
$ cd grpc
$ git submodule update --init
$ make
$ sudo make install
$ sudo ldconfig

Ubuntu

For Xenial (Ubuntu 16.04.4):

wget https://devhub.cisco.com/artifactory/debian-ydk/0.8.0/xenial/libydk_gnmi_0.4.0-1_amd64.deb
sudo gdebi libydk_gnmi_0.4.0-1_amd64.deb

For Bionic (Ubuntu 18.04.1):

wget https://devhub.cisco.com/artifactory/debian-ydk/0.8.0/bionic/libydk_gnmi_0.4.0-1_amd64.deb
sudo gdebi libydk_gnmi_0.4.0-1_amd64.deb

CentOS

sudo yum install https://devhub.cisco.com/artifactory/rpm-ydk/0.8.0/libydk_gnmi_0.4.0-1.x86_64.rpm

There is an open issue with gRPC on Centos/Fedora, which requires an extra step before running any YDK gNMI application. See this issue on GRPC GitHub for details. As a workaround, the YDK based application runtime environment must include setting of LD_LIBRARY_PATH variable:

$ PROTO="/Your-Protobuf-and-Grpc-installation-directory"
$ export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$PROTO/grpc/libs/opt:$PROTO/protobuf-3.5.0/src/.libs:/usr/local/lib64

You can install the latest model packages from the Python package index. Note that, in some systems, you need to install the new package as root. You get a fully operational YDK environment by installing the cisco-ios-xr and/or cisco-ios-xe bundle(s) (depending on whether you're developing for an IOS XR or IOS XE platform) which automatically installs all other YDK-related packages (ydk, openconfig and ietf packages):

.. code-block:: sh

$ pip install ydk-models-cisco-ios-xr $ pip install ydk-models-cisco-ios-xe

Alternatively, you can perform a partial installation. If you only want to install the openconfig bundle and its dependencies (ydk and ietf packages), execute:

$ pip install ydk-models-openconfig

If you only want to install the ietf bundle and its dependencies (ydk package), execute:

.. code-block:: sh

$ pip install ydk-models-ietf

To installation of model bundles on CentOS/RedHat platforms require special handling; please follow the below steps.

Python2.7:

pip install ydk
pip install --install-option="--install-purelib=/usr/lib64/python2.7/site-packages" --no-deps ydk-models-ietf
pip install --install-option="--install-purelib=/usr/lib64/python2.7/site-packages" --no-deps ydk-models-openconfig
pip install --install-option="--install-purelib=/usr/lib64/python2.7/site-packages" --no-deps ydk-models-cisco-ios-xr
pip install --install-option="--install-purelib=/usr/lib64/python2.7/site-packages" --no-deps ydk-models-cisco-ios-xe

Python3.4:

pip install ydk
pip install --install-option="--install-purelib=/usr/lib64/python3.4/site-packages" --no-deps ydk-models-ietf
pip install --install-option="--install-purelib=/usr/lib64/python3.4/site-packages" --no-deps ydk-models-openconfig
pip install --install-option="--install-purelib=/usr/lib64/python3.4/site-packages" --no-deps ydk-models-cisco-ios-xr
pip install --install-option="--install-purelib=/usr/lib64/python3.4/site-packages" --no-deps ydk-models-cisco-ios-xe

Python3.6:

pip install ydk
pip install --install-option="--install-purelib=/usr/lib64/python3.6/site-packages" --no-deps ydk-models-ietf
pip install --install-option="--install-purelib=/usr/lib64/python3.6/site-packages" --no-deps ydk-models-openconfig
pip install --install-option="--install-purelib=/usr/lib64/python3.6/site-packages" --no-deps ydk-models-cisco-ios-xr
pip install --install-option="--install-purelib=/usr/lib64/python3.6/site-packages" --no-deps ydk-models-cisco-ios-xe

If you prefer not to use the YDK packages in the Python package index, you need to install manually the ydk core package and then the model bundles you plan to use. To install the ydk core package, execute:

.. code-block:: sh

$ cd core core$ python setup.py sdist core$ pip install dist/ydk*.gz

Once you have installed the ydk core package, you can install one more model bundles. Note that some bundles have dependencies on other bundles. Those dependencies are already captured in the bundle package. Make sure you install the desired bundles in the order below. To install the ietf bundle, execute:

.. code-block:: sh

core$ cd ../ietf ietf$ python setup.py sdist ietf$ pip install dist/ydk*.gz

To install the openconfig bundle, execute:

.. code-block:: sh

ietf$ cd ../openconfig openconfig$ python setup.py sdist openconfig$ pip install dist/ydk*.gz

To install the cisco-ios-xr bundle, execute:

.. code-block:: sh

openconfig$ cd ../cisco-ios-xr cisco-ios-xr$ python setup.py sdist cisco-ios-xr$ pip install dist/ydk*.gz cisco-ios-xr$ cd ..

You may want to perform the installation under a Python virtual environment (virtualenv/virtualenvwrapper). A virtual environment allows you to install multiple versions of YDK if needed. In addition, it prevents any potential conflicts between package dependencies in your system.

To install virtual environment support in your system, execute:

.. code-block:: sh

$ pip install virtualenv virtualenvwrapper $ source /usr/local/bin/virtualenvwrapper.sh

In some systems (e.g. Debian-based Linux), you need to install support for Python virtual environments as root:

.. code-block:: sh

$ sudo pip install virtualenv virtualenvwrapper $ source /usr/local/bin/virtualenvwrapper.sh

Create a new virtual environment:

.. code-block:: sh

$ mkvirtualenv -p python2.7 ydk-py

At this point, you can perform the quick install or the installation from source described above. Take into account that must not attempt to install YDK as root under a virtual environment.

• Read the API documentation for details on how to use the API and specific models
• Samples can be found under the samples directory
• Hundreds of additional samples can be found in the YDK-PY samples repository
• Join the YDK community to connect with other users and with the makers of YDK
• Additional YDK information can be found at ydk.io

The current YDK release version is 0.8.0. YDK-Py is licensed under the Apache 2.0 License.