Copyright 2015, Cisco Systems, Inc

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

END OF SUPPORT

As of 18th August 2020 this application is no longer maintained. Developers are free to use the code as-is, including forking, but no more updates will be forthcoming from the project maintainers and any new or outstanding issues will neither be tracked nor responded to.

For a potential alternative, see YANG Suite.

1. Description

An open-source Yang Browser and RPC Builder Application to experiment with Yang Data Models

Features

• Upload / Compile yang models from User Interface Or Command Line
• Build NetConf RPC
• Generate Python example code [new]
• Search yang xpaths [new]
• Execute RPC against real netconf server
• Save created RPCs to collections for later use
• Build dependency graph for models
• Browse data model tree and inspect yang properties

Restconf support is experimental

This application is under Beta mode, contributions / suggestions are welcome !!

Screenshots:

2. Installation

2.1 First time installation

Prerequisite:

• MAC, Linux (not supported on Windows)
• python 2.7
• pip package manager (https://pip.pypa.io/en/stable/installing/)

   If already installed, make sure that pip / setuptools are upto date (commands may vary)
   
   pip install --upgrade pip
   
   Ubuntu: sudo pip install --upgrade setuptools

• virtualenv (recommended)

   Ubuntu: sudo apt-get install python-virtualenv
   Fedora: sudo dnf install python-virtualenv
   MAC: sudo pip install virtualenv

• graphviz (http://www.graphviz.org/Download.php)

   Ubuntu: sudo apt-get install graphviz
   Fedora: sudo dnf install graphviz
   MAC: brew install graphviz

• Browser with latest flash plugin (tested with google chrome)

Download and install:

   git clone https://github.com/CiscoDevNet/yang-explorer.git
   cd yang-explorer
   bash setup.sh

   Note: sudo may be required if you do not use virtualenv.

See section 7 Troubleshooting for more:

   If you get installation error for missing python.h or xmlversion.h try installing
   dependency packages:
   
   Ubuntu: sudo apt-get install libxml2-dev libxslt1-dev python-dev zlib1g-dev
   Fedora: sudo dnf install libxml2-devel libxslt-devel python-devel zlib-devel

2.2 Update exising installation

  cd <install-root>/yang-explorer
  git stash (if you have local changes)
  git pull origin
  git stash apply (if you have local changes)
  bash setup.sh

2.3 Backing up data

YangExplorer data can be backed up from data directory and it is portable to new servers -

   cp -r <install-root>/yang-explorer/server/data <backup-location>/data

Restore from backup location -

   cd <install-root>/yang-explorer/server

   # move current data to tmp location
   mv data data_old
   
   # replace data from backup location
   cp -r <backup-location>/data data

3. Running YangExplorer

3.1 Running with localhost

Start Server:

   cd <install-root>/yang-explorer
   [sudo] ./start.sh &

   Note: sudo may be required if you did not use virtualenv during installation.

Start Explorer:

   http://localhost:8088/static/YangExplorer.html

3.2 Running with ip-address (Shared server)

Start Server:

   # Determine <ip-address> using if-config
   
   # Add ip-address/port in YangExplorer.html after following line:
   cd <install-root>/yang-explorer/server/static
      vi YangExplorer.html
      var flashvars = {}; 
+     flashvars.host = '<ip-address>';
+     flashvars.port = '8088';

   # save & quit

   # Update ip-address in startup script
      cd <install-root>/yang-explorer
      vi start.sh
      (update HOST variable with <ip-address>)
   # save & quit
      
   ./start.sh

   Note: sudo may be required if you did not use virtualenv during installation.

Start Explorer:

   http://<ip-address>:8088/static/YangExplorer.html

4. Caveats

• Yang Model upload fails, Workaround: Use Google Chrome.
• See section 6 Troubleshooting for more:

5. User Guide (TBD)

5.1 Work Flow

5.2.1 Login:

YangExplorer uses user accounts to manage workspaces. You can create a user account using admin page (See 5.3.1 Creating User Account) or use the predefined login (guest/guest). You must login (click on the Login button on top right corner)

You can use guest login (guest/guest) or newly created account.

5.2.2 Adding/Deleing Yang Models:

Upload using yang-explorer user interface (TBD: screen shot is out-of-date)

• Click Manage Models tab
• Click Workspace tab
• Click Add button
  • Click Browse and select models to upload
  • Click Upload
  • Clear button can be used clear models in upload window
• Click Subscribe & Un-subscribe buttons to make selected models visible/invisible in explorer area
• Click Delete button to delete selected models from user account

Sync from Device

• Click Manage Models tab
• Click Device tab
  • Select a device from profile list
    • YangExplorer will list yang models on device
  • Select models to Sync to YangExplorer Workspace
  • Sync button to Sync Models to YangExplorer
  • You may encounter these error during sync:
    • Missing models: Select missing models from the list and try sync again
    • Duplicate models: In workspace tab, select duplicate models and delete
• Click Workspace tab
• Click Subscribe & Un-subscribe buttons to make selected models visible/invisible in explorer area
• Click Delete button to delete selected models from user account

Upload models using server console

   cd <install-root>/yang-explorer
   source v/bin/activate
   cd server
   python manage.py --user <username> --git <git-url> --dir <path/to/yang/models>
   
   example: local upload (assumes models are already available at dir path)
   python manage.py bulkupload --user guest --dir /users/prgohite/git/yang/vendor/cisco/xr/531
   
   example: git upload
   python manage.py bulkupload --user guest --git https://github.com/YangModels/yang.git --dir vendor/cisco/xr/531

All models must be compiled successfully, in case of any error none of the models will be uploaded to yang-explorer.

5.2.3 Generating the model dependency graph:

• Click Manage Models tab
• Click Workspace tab
  • Select one or more model name to get dependency graph
  • If no models are selected, all subscribed model will be used to generate graph
• Click Graph buttons to generate graph

5.2.4 Creating RPCs:

You can explore yang models in explorer area (left pane) using tree navigation:

• Value and Operation columns in explorer area are editable.

• Explore model in explorer area by navigating model tree

• Click value cell next to data node (leaf, container etc)

• Edit values

  • Select <get> and <get-config> for get, get-config netconf operations
  • Select <rpc> for RPCs
  • Enter data values for edit-config operation
  • Use Reset button on top-right bar to reset data in the model tree

• Update netconf operations for edit-config (optional advance option)

![alt tag](https://github.com/CiscoDevNet/yang-explorer/blob/master/docs/images/netconf-operations.png)
  - Select **Operations** tab
  - Select error-option
  - Check / Uncheck lock option

• Click RPC button under Build tab

5.2.5 Executing RPCs:

• Create RPC using 5.2.4
• Populate Device info in Device Settings Tab
• Click Run button under Build tab

Yang Explorer uses ncclient library to execute RPCs, connection timeout can be configured via environment varible default timout value is 45 seconds.

   #update value in start.sh & restart server
   export NCCLIENT_TIMEOUT=120

5.2.6 Generating Python example:

• Create a netconf / xml RPC - Create RPC using 5.2.4 - (OR) Provide custom netconf XML (Click custom RPC Checkbox)

• Click Script button under Build tab

• Click Copy button to copy generated code into system clipboard

• Save content as a python script (say example.py)

• Run python script from command line using given instruction in script header comments.

5.2.7 Saving RPCs to Collection:

• Create RPC using 5.2.4
• Click Save button under Build tab

5.2.8 Loading saved RPC:

• Click Collections Tab
• Double click on the RPCs title you want to load.

5.3 Admin Tasks

5.3.1 Creating User Account (optional):

Creating user account is optional as you can use default guest/guest login, however creating user account can be userful if you have a shared yang-explorer installation.

• Click Admin button in YangExplorer
• Login as admin (user: admin, password: admin)
• On admin page, click Users link
• On User Profiles page, click Add user link (top-right)
• Add user account info and click Save (Warning: passwords are transmitted in plaintext)

5.3.2 Creating Device Profiles:

Device profiles can be created to quickly populate device info from drop-down list in yang-explorer.

Note: You can use default user login (guest/guest)

• Click "Create device profile" link on Build -> Device Settings
• (OR) Click "Create device profile" link on Manage Models -> Device
• (OR) Click Admin button in YangExplorer
  • Login login as guest or your own login
  • On admin page, click Device profiles link
• On User Profiles page, click Add device profiles link (top-right)
• Add device credentials (device login info is not secured)
  • Add netconf credentials (Required for connecting to netconf server)
  • Add restconf credentials (Not used currently)
• click Save

5.3.3 Creating Collection:

Collections can be used to save user generated RPCs on the server so that saved RPCs can be re-used.

Note: You can use default user login (guest/guest)

• Click Admin button in YangExplorer
• Login login as guest or your own login
• On admin page, click Collections link
• On User Profiles page, click Add collection link (top-right)
  • Provide collection name
  • Select User from drop-down box
  • Provide description for this collection
• click Save

6 Misc Features

6.1 UI Model Tree annotations

Targeted content in YangExplorer UI tree can be annotated in different color, usually to represent additional information about of the Yang model node.

Installation:

  cd <install-root>/yang-explorer
  bash setup.sh -a <path to annotation json file>

Please refresh browser to reflect changes. You should see UI model tree node name in different color as per annotation file.

Uninstall:

  cd <install-root>/yang-explorer
  bash setup.sh -r

7 Troubleshooting

7.1 Installation

7.1.1 error for missing python.h or xmlversion.h

• Ubuntu: sudo apt-get install libxml2-dev libxslt1-dev python-dev
• Mac : xcode-select --install

7.1.2 django.db.utils.OperationalError: near "񐁂򐁇N": syntax error

• http://stackoverflow.com/questions/33270297/django-db-utils-operationalerror-near-n-syntax-error

7.1.3 After install if you are not able to login using guest/guest try one of the following

• mv server/data/db.sqlite3 server/data/db.sqlite3_backup
• bash setup.sh In end of setup.sh script log you should see something like this -

      ...
      Creating default users ..
      Copying default models ..
      Setup completed.. 
      
      Use start.sh to start yang-explorer server

7.1.4 Installation failed due to python 3 not supported

Python 3 is not supported by ncclient. Please install python 2.7 before proceeding futher. If python 2.7 is already installed on your system along with python 3, virtualenv may try to create python 3 environment. You can do following -

cd YangExplorer
rm -rf v

# find path to python 2.7 on your system
➜  ~  which python2.7   
/usr/bin/python2.7

# create a virtualenv with python 2.7, path may differ based on your installation
virtualenv -p /usr/bin/python2.7 v

# rerun setup
setup.sh

7.2 Yang Model Upload

7.2.1 Failure during upload of yang model

• Chrome browser is required currently to upload models using User Interface
• Please see failure message, if dependent models are missing you will see specific error in message window.