Last updated on April 20, 2016

This article shows you how to set up open source Netopeer server on Ubuntu 15.04 or 15.10 and Fedora 20 to use with Seguesoft's NETCONFc client. Officially Netopeer distribution claims it only supports RHEL and SUSE but it should just run fine on other Linux distributions such as Ubuntu and Fedora.

More recent Netopeer distribution has a Dockerfile that can be used to create a container that builds netopeer-server and starts the service. You need a linux with working docker installation to use it. This article does not cover that, rather, it focuses on the classic way (i.e., configure, make & make install) of installing Netopeer from source.

Note Well

1. Build libnetconf

2. Build netopeer server

3. Start netopeer server

4. Connect to netopeer server from NETCONFc

5. Configure netopeer server modules using netopeer-manager

Troubleshooting

    * No package 'libnetconf' found when running ./configure for netopeer server

    * D-Bus error: connection is not allowed to own the service "org.liberouter.netopeer.server" when server

    * 'Could not open socket to x.x.x.x:830'  error when connecting from NETCONFc

    * 'Unexpected session close or server is not running' when connecting to netopeer server from NETCONFc.

    * NACM: Module init failed when running netopeer-configurator

    * C compiler cannot create executable or cannot run C compiled programs

    * lnctool not found when running configure

    * When trying to create a connection from NETCONFc, the server says:
       np_ssh_create_client: SSH failed to accept a new connection: Failed to import private RSA host key

    * Can't make netopeer server to only listen on IPv4 on a different port?

  

Note Well:

Netopeer server is the leading open source NETCONF reference implementation. It has many features but sometimes it may prove to be a challenging task to gather all pieces and get it installed successfully on your Linux box. 

The following instructions are tested Ubuntu 15.04 or 15.10 x86_64 and Fedora 20 x86_64 systems. It is assumed that the system on which netopeer will be installed is an Ubuntu 15.04 or 15.10 desktop or Fedora 20, out-of-box default installation.

These instructions are based on a snapshot of libnetconf and netpeer github source repository on April 20, 2016. Future netopeer releases may require different system packages to be installed. If you find a discrepancy please inform us at This email address is being protected from spambots. You need JavaScript enabled to view it.

Please read the README and/or INSTALL file comes with libnetconf and netopeer distribution for latest information!

Other distributions and versions of Linux should be similar.  The key is to identify the names of various dependent packages of netopeer and install them according. A full list of packages that Netopeer depends on is oftern different based on what packages have already been installed on your system.  You will surely know what are are needed when you run libnetconf's and netopeer's ./configure script to generate Makefiles. If any of them is missing you must install them first.

  

1. Build libnetconf

1.1 Get libnetconf source :

$ git clone https://github.com/CESNET/libnetconf.git

1.2 Install the following required packages:

On Ubuntu 15.04 or 15.10:

$ sudo apt-get install libtool
$ sudo apt-get install libtool-bin
$ sudo apt-get install libxml2-dev
$ sudo apt-get install libxslt1-dev
$ sudo apt-get install libcurl4-openssl-dev
$ sudo apt-get install xsltproc
$ sudo apt-get install python-setuptools 
$ sudo apt-get install cmake 
$ sudo apt-get install zlib1g-dev
$ sudo apt-get install libssl-dev
$ sudo apt-get install pkg-config
$ sudo apt-get install lib-readline-dev

 

 On Fedora 20+:

$ sudo yum install libtool
$ sudo yum install libxml2-devel
$ sudo yum install libxslt-devel
$ sudo yum install libcurl-devel
$ sudo yum install python-setuptools
$ sudo yum install pkg-config
$ sudo yum install readline-devel

 

1.3 Install pyang

On either Ubuntu 15.04 or 15.10 or Fedora 20:

$ git clone https://github.com/mbj4668/pyang.git
$ cd pyang
$ sudo python setup.py install
$ cd ..

 

1.4 Install libssh

On Fedora 20+:
We can simply use the system provided libssh-devel 0.6.4

$ sudo yum install libssh-devel

On Ubuntu15.04 or 15.10+:

We need to build the latest libssh ourselves since the system installed libssh is 0.6.3 but libnetconf (and Netopeer server) needs at least 0.6.4.
If you have libssh0.6.3 installed on the system, remove it and the compile libssh 0.6.4 from the source code.

Get libsssh source and build it:

   $ git clone https://git.libssh.org/projects/libssh.git libssh
   $ cd libssh
   $ mkdir build
   $ cd build
   $ cmake ..
   $ make
   $ sudo make install
   $ cd ..

1.5 Now finally we can build libnetconf:

$ ./configure
$ make
$ sudo make install

If libnetconf’s configure scripts still can't find the libssh you just installed,  try setting up the following compiler flags before running './configure':

export CPPFLAGS='-I/usr/local/include'
export LDFLAGS='-L/usr/local/lib'

Alternatively you can try installing libssh in /usr, rather than the default /usr/local. To do that, first remove all contents in your libssh ‘build’ directory,
cd build
rm -rf *

then

cmake -DCMAKE_INSTALL_PREFIX=/usr ..
make
sudo make install 

 

2. Build netopeer server

2.1 Get netopeer source

$ git clone https://github.com/CESNET/netopeer.git

2.2 Install dependent package

Ubuntu 15.04 or 15.10: 

$ sudo apt-get install python-libxml2

Fedora 20:

$ sudo yum install libxml2-python

(Note this step may be not be needed since it may have been installed along with libxml2-devel rpm. )

2.3 Build Netopeer server

      $ cd netopeer/server
      $ ./configure      

On Fedora20+, if you get the following error:
configure: error: Package requirements (libnetconf) were not met:
No package 'libnetconf' found
Consider adjusting the PKG_CONFIG_PATH environment variable if you
installed software in a non-standard prefix.

If so, setup PKG_CONFIG_PATH environment variable to point to libnetconf pkg explicitly,  as shown below:

$ export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig

then redo

$ ./configure

      $ make
      $ sudo make install


 2.4. Build TransAPI cfgsystem example (ietf-system module sample implementation)

    If this cfgsystem is installed, you should be able to view ietf-system module in NETCONFc.

    First install dependent augeas package
    Ubuntu: 

$ sudo apt-get install libaugeas-dev  

   Fedora:        
       $ sudo yum install augeas-devel

   Then we can build it:

$ cd netopeer/transAPI/cfgsystem
$ ./configure


Note ./configure above may fail because a missing ietf-inet-types.yang module, if that happens, copy This email address is being protected from spambots. You need JavaScript enabled to view it. shipped with NETCONFc, rename it to ietf-inet-types.yang and place it into the source folder. So we have

netopeer/transAPI/cfgsystem/model/ietf-inet-types.yang

and then we redo
$ ./configure

$ make
$ sudo make install

3. Start netopeer server:

Ubuntu 15.04 or 15.10:

On a desktop Ubuntu system installed with default configurations, we must install openssh-server in order to run Netopeer, (or ssh into the box in general). 

$ sudo apt-get install openssh-server 

Then we can start netopeer:

$ sudo /usr/local/bin/netopeer-server -d

Fedora 20:

       $ su (log in as root, then)
       First, we need add /usr/local/lib into dynamic library search path:
       # export LD_LIBRARY_PATH=/usr/local/lib:$LD_LIBRARY_PATH 
       Then we need to disable firewall since it is enabled by default
       # systemctl stop firewalld
       # systemctl disable firewalld
       Finally we can start netopeer server
       # /usr/local/bin/netopeer-server  -d


The -d option makes the server to start in a daemon mode. You can also set logging verbosity by specifying parameter for the -v option from 0 to 3 (errors, warnings, verbose, debug).

 

4. Connect to netopeer server from NETCONFc

Start NETCONFc, click the 'Connect SSH' toolbar button, enter server’s host name or IP address, port number, user name and password. By default you should be able to use any SSH user configured in your Ubunto box to connect to it. Later you can enable NACM settings to restrict access.

Then click the button “Connect” on the session creation dialog. You should be connected to the server. If error happens, check if the server is running on the specified address and port. Also make sure the correct user name and password are used. See more in troubleshooting section.

For details on how to create a session from NETCONFc and browse default modules on netopeer server, see NETCONFc's menu Help->Help Topics ->First steps with NETCONFc

5. Configure netopeer server modules

To find out the default location to add YANG modules, run

$ sudo /usr/bin/netopeer-configurator

You can find the following information in [Netopeer] section


[Netopeer]          Using modules installed in path:  /usr/local/etc/netopeer/modules.conf.d

By default all modules's XML instance data (Netopeer calls this datastore, unfortunately the same terminology used as NETCONF's running/candidate/startup datastore) are stored in /usr/local/etc/netopeer/modules.conf.d

When you add a module using netopeer-manager, the --datastore option should point to /usr/local/etc/netopeer/modules.conf.d

Example of using netopeer-manager:

First check what modules are enabled by default:

  netopeer-manager list


List of startup Netopeer modules:
No module installed.

Ok, no modules are installed. Let's add some modules. To add a model, first convert .yang file .yin file using Pyang or Seguesoft's NETCONFc. Netopeer uses YIN format internally. As an example, let's add toaster datastore so you can use NETCONFc to configure it.

 Download toaster.yang from http://seguesoft.com/get-standard-yang-modules. Then you can do:


$ pyang -f yin /home/bob/YANG_modules/toaster.yang -o /home/bob/YANG_modules/toaster.yin

Then add toaster.yin's datastore into Netopeer as follows

# netopeer-manager add --name toaster --model /home/bob/YANG_modules/toaster.yin --datastore /usr/local/etc/netopeer/modules.conf.d/toaster.xml

For command reference type      

  netopeer-manager add --help     

To actually implement a model, see http://github.com/CESNET/netopeer/tree/master/transAPI/cfgsystem

 

Possible errors

* No package 'libnetconf' found when running ./configure for netopeer server

 On some systems such as Fedora x64, even if we install netconf into the default folder /usr/local, when compiling netopeer server it may fail with the following error:

 checking for LIBNETCONF...

configure: error: Package requirements (libnetconf) were not met: No package 'libnetconf' found

We can workaround this by doing the following before running ./configure:

 

export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig

You may also need to adjust the PKG_CONFIG_PATH environment variable if you installed software in a non-standard prefix.

Note In a typical Unix system, it will search in the directories /usr/lib/pkgconfig and /usr/share/pkgconfig. This will usually cover system installed modules. However, some local modules may be installed in a different prefix such as /usr/local. In that case, it's necessary to prepend the search path so that pkg-config can locate the .pc files.

 

$ pkg-config --modversion libnetconf

Package libnetconf was not found in the pkg-config search path. Perhaps you should add the directory containing `libnetconf.pc' to the PKG_CONFIG_PATH environment variable.

 

$ export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig
$ pkg-config --modversion libnetconf

  0.8.0

 * D-Bus error: connection is not allowed to own the service "org.liberouter.netopeer.server" when trying to start the server

When attempting to start netopeer server, you may get this error.

You need to use --with-dbus-services when running ./configure to generate makefile for netopeer server.

* 'Could not open socket to x.x.x.x:830' when connecting from NETCONFc.

The server is not running, or there is firewall between NETCONFc and Netopeer server that may be blocking port 830.

You can test this by quickly disabling Firewall

check the status of the firewall:

#systemctl status firewalld

to disable it:
#systemctl stop firewalld

#systemctl disable firewalld

 

You may also need to disable your SELinux or add port 830 as an additional port allowed by SELinux. For example, on Fedora:

 sudo semanage port -a -t ssh_port_t -p tcp 830

 sudo systemctl restart sshd

To disable SELinux,

vi /etc/selinux/config and change to use "disabled", save and restart your computer.  To verify:

getenforce

>>Disabled

 To set SELinux to permissive without restarting your computer

sudo setenforce  0

 

* 'Unexpected session close or server is not running' when trying to connect to netopeer server from NETCONFc


This usually indicated netopeer-agent could not be started successfully, perhaps because it was not able to locate dependent libraries etc.

First, try adding /usr/local/lib (or prerix/lib, if you used --prefix when running ./configure) into library search path. To do this, when logged in as root,

# vi /etc/ld.so.conf

and then add a new line /usr/local/lib at the end. So after editing it looks like:

/include ld.so.conf.d/*
/usr/local/lib

save and run the following command:

# ldconfig

If it still does not work, try manually connect to it and check logs for hints:

# ssh yourUserName@your-netopeer-server -p 830 -s netconf -F /usr/local/etc/netopeer/sshd_config

Check sshd log for additional hint:

cat /var/log/secure

If you see the following line:

pam+; pgomuid(sshd:session): set_loginuid failes

It's because the kernel doesn't have AUDIT enabled. So you get a bunch of errors in "/var/log/secure" with "set_loginuid failed opening loginuid".

Then just comment this line in file "/etc/pam.d/sshd":

#session required pam_loginuid.so

It's most likely because the Linux kernel you are using doesn't have AUDIT enabled. This may happen on some Linux installations or Linux VM installed on Oracle Virtual box . If you have no way to recompile kernel just disable pam_loginuid.so as shown above

 

NACM: Module init failed when running netopeer-configurator


Usually this means you need to update PKG_CONFIG_PATH.

export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig for root before invoking this command.)

in root user's .bashrc file: export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig

 

 C compiler cannot create executable

If you get an error complaining " C compiler cannot create executable" when doing ./configure

Please make sure you have a complete working c development environment installed, and you may need to use the recent or latest C compiler

For example on Fedora you need to do

yum install "Development Tools"

You may also need to install the following packages:

yum install libssh2-devel
yum install xslt-devel
yum install libcurl-devel
yum install xsltproc


On ubuntu:
sudo apt-get install libssh2-1-dev
sudo apt-get install libxslt1-dev
sudo apt-get install libcurl4-openssl-dev

 

 Inctool not found when running netopeer configure

This usually indicates libnetconf was not built with Pyang present. Check if you have Python and Pyang installed. If not first install them and then resinstall libnetconf

 

 netopeer-server: np_ssh_create_client: SSH failed to accept a new connection: Failed to import private RSA host key

This indicates ssh server is not enabled. On ubuntu Desktop, SSH is not installed or enabled by default in Ubuntu Desktop edition, to enable it:

 

sudo apt-get install openssh-server

sudo /etc/init.d/ssh restart

 Can't make NETOPEER server to listen on IPv4 only or a specific port

You need to change the startup config in /usr/local/etc/netopeer/cfgnetopeer/datastore-server.xml like the following:

<?xml version="1.0" encoding="UTF-8"?>
<datastores xmlns="urn:cesnet:tmc:datastores:file">
  <running lock=""/>
  <startup lock="">
    <netconf xmlns="urn:ietf:params:xml:ns:yang:ietf-netconf-server">
      <ssh>
        <listen>
          <interface>
            <address>0.0.0.0</address>
            <port>830</port>
          </interface>
        </listen>
      </ssh>
    </netconf>
  </startup>
  <candidate modified="false" lock=""/>
</datastores>