Table of Contents
- Getting Started
- Backward Compatibility
- System Requirements
- Quick install
- Installing from Source
- Using Python Virtual Environment
- Documentation and Support
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.
The Python YDK-0.8.3 core package is compatible with all model bundles generated previously with ydk-gen releases starting from 0.7.3. Please see the release notes for details.
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.
docker run -it ydkdev/ydk-py
Please follow the below instructions to install the system requirements before installing YDK-Py:
Download and install third party dependency packages and then 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.
Install Third-party software dependencies:
sudo apt-get install gdebi-core python3-dev python-dev libtool-bin sudo apt-get install libcurl4-openssl-dev libpcre3-dev libssh-dev libxml2-dev libxslt1-dev cmake
For Xenial (Ubuntu 16.04.4):
# 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++ # Install YDK core library wget https://devhub.cisco.com/artifactory/debian-ydk/0.8.3/xenial/libydk-0.8.3-1.amd64.deb sudo gdebi libydk-0.8.3-1.amd64.deb
For Bionic (Ubuntu 18.04.1):
# Install YDK core library wget https://devhub.cisco.com/artifactory/debian-ydk/0.8.3/bionic/libydk-0.8.3-1.amd64.deb sudo gdebi libydk-0.8.3-1.amd64.deb
Note: Currently, only Centos7 and RHEL7 are known to work with YDK. Please see this issue on YDK GitHub for any potential/usage installation on CentOS.
The following packages must be present in your system before installing YDK-Py:
# Install Third-party software dependencies sudo yum install epel-release sudo yum install libssh-devel gcc-c++ python-devel python3-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/0.8.3/libydk-0.8.3-1.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.
# Install Third-party software dependencies xcode-select --install /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)" brew install pkg-config libssh xml2 libxml2 curl pcre cmake pybind11 # Install YDK core library curl -O https://devhub.cisco.com/artifactory/osx-ydk/0.8.3/libydk-0.8.3-Darwin.pkg sudo installer -pkg libydk-0.8.3-Darwin.pkg -target /
The libssh-0.8.0 does not support separate threading library, which is required for YDK. If after installation of libssh package the libssh_threads.a is missing, please downgrade the installation to libssh-0.7.6, or upgrade to libssh-0.8.1 or higher.
In order to enable YDK support for gNMI protocol, which is optional, the following third party software must be installed prior to gNMI YDK component installation.
wget https://github.com/google/protobuf/releases/download/v3.5.0/protobuf-cpp-3.5.0.zip unzip protobuf-cpp-3.5.0.zip cd protobuf-3.5.0 ./configure make sudo make install sudo ldconfig
git clone -b v1.9.1 https://github.com/grpc/grpc cd grpc git submodule update --init sudo ldconfig make sudo make install
For Xenial (Ubuntu 16.04.4):
wget https://devhub.cisco.com/artifactory/debian-ydk/0.8.3/xenial/libydk_gnmi_0.4.0-2_amd64.deb sudo gdebi libydk_gnmi_0.4.0-2_amd64.deb
For Bionic (Ubuntu 18.04.1):
wget https://devhub.cisco.com/artifactory/debian-ydk/0.8.3/bionic/libydk_gnmi_0.4.0-2_amd64.deb sudo gdebi libydk_gnmi_0.4.0-2_amd64.deb
sudo yum install https://devhub.cisco.com/artifactory/rpm-ydk/0.8.3/libydk_gnmi_0.4.0-2.x86_64.rpm
curl -O https://devhub.cisco.com/artifactory/osx-ydk/0.8.3/libydk_gnmi-0.4.0-2_Darwin.pkg sudo installer -pkg libydk_gnmi-0.4.0-2_Darwin.pkg -target /
There is an open issue with gRPC on Centos/Fedora, which requires an extra step before running any YDK gNMI application. See this issue on GRPC GitHub for details. As a workaround, the YDK based application runtime environment must include setting of LD_LIBRARY_PATH variable:
PROTO="/Your-Protobuf-and-Grpc-installation-directory" export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$PROTO/grpc/libs/opt:$PROTO/protobuf-3.5.0/src/.libs:/usr/local/lib64
YDK supports both Python2 and Python3 versions. At least Python2.7 or Python3.4 must be installed on your system.
It is also required for Python installation to include corresponding shared library. As example:
python2.7 - /usr/lib/x86_64-linux-gnu/libpython2.7.so python3.5m - /usr/lib/x86_64-linux-gnu/libpython3.5m.so
Please follow System Requirements to assure presence of shared Python libraries.
The developers of Python2 on Mac OS might face an issue ([#837](https://github.com/CiscoDevNet/ydk-gen/issues/837)). This is well known and documented issue. Each developer might have different approaches for its resolution. One of them is to use Python2 virtual environment. See section Using Python Virtual Environment for details.
In addition it is required properly set CMAKE_LIBRARY_PATH environment variable to assure that cmake uses correct Python library. Follow these steps to find and set correct library path.
- Find installations of libpython2.7 library:
$ locate libpython2.7.dylib /System/Library/Frameworks/Python.framework/Versions/2.7/lib/libpython2.7.dylib /System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/config/libpython2.7.dylib /usr/lib/libpython2.7.dylib /usr/local/Cellar/python@2/2.7.15_1/Frameworks/Python.framework/Versions/2.7/lib/libpython2.7.dylib /usr/local/Cellar/python@2/2.7.15_1/Frameworks/Python.framework/Versions/2.7/lib/python2.7/config/libpython2.7.dylib
- Choose non-system Python library installation and set CMAKE_LIBRARY_PATH before any YDK component installation. Example:
- Run YDK core package installation with ‘-v’ flag to check that PythonLibs points to correct library path. Example:
./generate.py --core pip install -v gen-api/python/ydk/dist/ydk*.tar.gz
- In ‘cmake’ log look for ‘PythonLibs’ and ‘found version’ settings line:
-- Found PythonLibs: /usr/local/Cellar/python@2/2.7.15_1/Frameworks/Python.framework/Versions/2.7/lib/libpython2.7.dylib (found version "2.7.15")
- Finally test you YDK core library installation from CLI, making sure there are no errors:
python -c "import ydk.types"
You can install the latest model packages from the DevHub artifactory and Python package index. Note that, in some systems, you need to install the new package as root.
To install the core and model bundles on Centos, please follow the below steps.
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
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
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
You can install the latest model packages from the DevHub artifactory and Python package index.
Note that, in some systems, you need to install the new package as root.
You get fully operational YDK environment by installing the
(depending on whether you’re developing application for IOS XR or IOS XE platform), which automatically installs all other
YDK-related packages (
pip install ydk-models-cisco-ios-xr pip install ydk-models-cisco-ios-xe
Alternatively, you can perform a partial installation.
If you prefer to install only the
openconfig bundle and its dependencies (
ietf packages), execute:
pip install ydk pip install ydk-models-openconfig
If you only want to install the
ietf bundle and its dependencies (
YDK package), execute:
pip install ydk pip install ydk-models-ietf
To enable gNMI Service support in Python based application, install package:
pip install ydk-service-gnmi
If you prefer not to use the YDK packages in the DevHub artifactory or Python package index, you need to install manually the
YDK core package and then the model bundles that you plan to use.
The Python core package is dependent on C++ core library libydk, which must be installed prior to Python package installation:
$ git clone https://github.com/CiscoDevNet/ydk-gen.git $ cd ydk-gen/sdk/cpp/core core$ mkdir -p build core$ cd build build$ cmake .. build$ make build$ sudo make install
To install the
YDK Python core package, execute:
$ cd ydk-gen/sdk/python/core core$ python setup.py sdist core$ pip install dist/ydk*.gz
Once you have installed the
YDK core package, you can install one or more model bundles. The source code for the model bundles can be generated by running:
git clone https://github.com/CiscoDevNet/ydk-py.git -b 0.8.3
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:
core$ cd ../ietf ietf$ python setup.py sdist ietf$ pip install dist/ydk*.gz
To install the
openconfig bundle, execute:
ietf$ cd ../openconfig openconfig$ python setup.py sdist openconfig$ pip install dist/ydk*.gz
To install the
cisco-ios-xr bundle, execute:
openconfig$ cd ../cisco-ios-xr cisco-ios-xr$ python setup.py sdist cisco-ios-xr$ pip install dist/ydk*.gz cisco-ios-xr$ cd ..
Optionaly the gNMI package for Python can be installed. The Python gNMI package is dependent on C++ core library libydk (see installation of Python core package above) and C++ gNMI library libydk_gnmi, which must be installed prior to Python package installation:
$ cd ydk-gen/sdk/cpp/gnmi gnmi$ mkdir -p build gnmi$ cd build build$ cmake .. build$ make build$ sudo make install
To install the
YDK Python gNMI package, execute:
$ cd ydk-gen/sdk/python/gnmi gnmi$ python setup.py sdist gnmi$ pip install dist/ydk*.gz
You may want to perform the installation under 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 on your system, execute:
pip install virtualenv virtualenvwrapper source /usr/local/bin/virtualenvwrapper.sh
Create new virtual environment:
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 you must not attempt to install YDK as root under virtual environment.
To get started using the YDK API, there are sample applications available in the YDK-Py repository. For example, to run the
bgp.py sample, execute:
ydk-py$ cd core/samples samples$ ./bgp.py -h Usage: bgp.py [-h | --help] [options] Options: -h, --help show this help message and exit -v VERSION, --version=VERSION force NETCONF version 1.0 or 1.1 -u USERNAME, --user=USERNAME login user name -p PASSWORD, --password=PASSWORD login user password --proto=PROTOCOL Which transport protocol to use, one of ssh or tcp --host=HOST NETCONF agent hostname or IP address --port=PORT NETCONF agent SSH port (ydk-py)samples$ ./bgp.py --host <ip-address-of-netconf-server> -u <username> -p <password> --port <port-number>