Clixon runs on Linux, FreeBSD port. CPU architectures include x86_64, i686, ARM32.

You can also run Clixon in a docker container.

Ubuntu Linux

This section can be used for many other Linux distributions.


Install packages:

sudo apt-get install flex bison

Install and build CLIgen:

git clone
cd cligen;
make install

Add a clixon user and group, using useradd and usermod:

sudo useradd -M -U clixon
sudo usermod -a -G clixon <your user>
sudo usermod -a -G clixon www-data # Only if RESTCONF

If you do not require RESTCONF, then continue with Build from source.

RESTCONF reverse proxy

There are two RESTCONF variants. Either a reverse proxy solution using fcgi and (for example) nginx, based on the FastCGI protocol. To install:

sudo apt-get install nginx libfcgi-dev

Note that fcgi may have other names on other platforms: fcgi-dev(alpine), fcgi(arch), fcgi-devkit(freebsd)

Note that the libfcgi-dev package may not exist in Ubuntu 18 bionic or later, you may have to build fcgi from source),

RESTCONF native http

For RESTCONF using the native http solution you may need to build libevhtp from source since few platforms have it as package (freebsd is one exception). It also requires openssl 1.1 API (not 1.0)


The openssl 1.1 API is NOT default in some older OS:s such as Ubuntu 16.0.4, CentOS 7

Native http also requires libevent-2.1:

sudo apt-get install libevent-dev

Build from source

Download clixon source code:

git clone

Configure Clixon using one of the following RESTCONF variants:

configure --without-restconf
configure --with-restconf=fcgi   # Reverse proxy This is default
configure --with-restconf=native # Native http using libevhtp/libevent-2.1

For more configure options see: Configure options.

Build and install:

make                      # Compile
sudo make install         # Install libs, binaries, config-files and include-files


FreeBSD has ports for both cligen and clixon available. You can install them as binary packages, or you can build them in a ports source tree locally.

If you install using binary packages or build from the ports collection, the installation locations comply with FreeBSD standards and you have some assurance that the installed package is correct and functional.

The nginx setup for RESTCONF is altered - the system user www is used, and the restconf daemon is placed in /usr/local/sbin.

Binary package install

To install the pre-built binary package, use the FreeBSD pkg command:

% pkg install clixon

This will install clixon and all the dependencies needed.

Build from source on FreeBSD

If you prefer you can also build clixon from the FreeBSD ports collection

Once you have the Ports Collection installed, you build clixon like this

% cd /usr/ports/devel/clixon
% make && make install

One issue with using the Ports Collection is that it may not install the latest version from GitHub. The port is generally updated soon after an official release, but there is still a lag between it and the master branch. The maintainer for the port tries to assure that the master branch will compile always, but no FreeBSD specific functional testing is done.


Once installed, Clixon can be setup using systemd. The following shows an example with the backend and restconf daemons for the main example. Install them as /etc/systemd/system/example.service and /etc/systemd/system/example_restconf.service, for example.

Systemd backend

The backend service is installed at /etc/systemd/system/example.service, for example. Note that in this example, the backend installation requires the restconf service, which is not necessary.

Description=Starts and stops a clixon example service on this system
ExecStart=/usr/local/sbin/clixon_backend -s running -f /usr/local/etc/example.xml

Systemd restconf

The Restconf service is installed at /etc/systemd/system/example_restconf.service, for example:

Description=Starts and stops an example clixon restconf service on this system
ExecStart=/usr/local/sbin/clixon_restconf -f /usr/local/etc/example.xml

The restconf daemon can also be started using the clixon-lib process-control RPC. For more info, see RESTCONF.


Clixon can run in a docker container. As an example the docker directory has code for building and running the clixon test suite:

cd docker/main
make docker
make test

The docker tests are run in the Travis CI


Clixon uses vagrant in testing. For example to start a freebsd vagrant host, install Clixon and run the test suite, do

cd test/vagrant
./ freebsd/FreeBSD-12.1-STABLE

Other platforms include: ubuntu/bionic64 and generic/centos8

Build libevhtp from source

For RESTCONF using native http build evhtp from source as follows:

sudo git clone
cd libevhtp
./configure --libdir=/usr/lib
sudo make install

Note: Clixon native mode requires openssl 1.1 API which is NOT default in Ubuntu 16.0.4, CentOS 7 for example.

Build fcgi from source

For RESTCONF using fcgi build fcgi from source as follows:

git clone
cd fcgi2
./configure --prefix=/usr
sudo make install

SSH subsystem

You can expose clixon_netconf as an SSH subsystem according to RFC 6242. Register the subsystem in /etc/sshd_config:

Subsystem netconf /usr/local/bin/clixon_netconf

and then invoke it from a client using:

ssh -s <host> netconf

Configure options

The Clixon configure script (generated by autoconf) includes several options apart from the standard ones.

These include (standard options are omitted)
--enable-debug Build with debug symbols, default: no
 Include optional yang files in clixon install used for example and testing, default: no
 Enable publish of notification streams using SSE and curl
 Use CLIGEN here
 RESTCONF using fcgi/ reverse proxy. This is default.
 RESTCONF using native http with libevhtp
 set default path to config file
--with-libxml2 use gnome/libxml2 regex engine
 Install Clixon yang files here (default: ${prefix}/share/clixon)
 Install optional yang files here (default: ${prefix}/share/clixon)

There are also some variables that can be set, such as:

LINKAGE=static ./configure     # Build static libraries
CFLAGS="-O1 -Wall" ./configure # Use other CFLAGS (overridden by --enable-debug)