Given that Docker is already installed on the host machine, to run NoMachine server inside Docker it's enough to build an image from the Dockerfile and launch it.

For example to build an image with MATE as desktop environment:

Step 1 - Create your image directory, e.g. :

Step 2 - Copy content of the Dockerfile below to: nomachine/Dockerfile.
Adapt the Dockerfile to your needs.

Step 3 - Copy content of the wrapper script below to: nomachine/nxserver.sh. Then set executable permissions:

Step 4 - Build the image:

Step 5 - Run the container:

Set a different port if necessary (see points d and e below).

You can specify multiple ports by reiterating the -p option, e.g.

The Dockerfile is a script which contains a set of instructions used to build the container image.

See also the official Docker documentation https://docs.docker.com/engine/reference/builder/

The Dockerfile below uses the NoMachine package downloaded from the NoMachine website as an example. It can be easily adapted to your environment:

a) By default this Docker file will run a MATE desktop environment, you can adjust it by replacing mate-desktop-environment-core with the desktop of your choice.

b) It will create the nomachine user with 'nomachine' as a password, you can specify a different username and password and repeat instructions for creating additional users.

c) Note that there is no need to expose ports in Dockerfile, this can be done by using the -p option when running the 'docker run' command. E.g.

e) Connections by the web use port 4080 and 4443 by default. Run:

to let users run web sessions. This applies to NoMachine servers supporting sessions by the web only.

Docker file

The nxserver.sh wrapper script

Troubleshooting

On some systems, e.g. Ubuntu 14.04 , AppArmor blocks many operations.

If the system logs report a message similar to:
apparmor="DENIED" operation="ptrace" profile="docker-default" pid=3004 comm="nxexec" requested_mask="read" denied_mask="read" peer="docker-default"

it's necessary to reconfigure AppArmor to let NoMachine access /proc filesystem. To do this you may install the AppArmor Utilities if you don't have them already:

If you get an error like the following while executing 'sudo aa-complain /etc/apparmor.d/docker':
apparmor.common.AppArmorException: 'Syntax Error: Invalid Regex @{PROC}/{*,**^[0-9*],sys/kernel/shm*} in file: /etc/apparmor.d/docker line: 16'

comment out the corresponding line (in this case line 16) in the /etc/apparmor.d/docker file.
Then execute once again this command:

Finally restart the container, NOT the docker service.

On Ubuntu 16.04, besides following the above instructions, it's also necessary to enable PTRACE capabilities required by NoMachine. Since PTRACE is not provided by the default docker AppArmor profile, add the --cap-add=SYS_PTRACE parameter to the docker command line, e.g.:

This point applies also to Mac.

This use case provides some example to illustrate how to set-up a browser, office suite, VOIP program and e-mail client in a Docker and run it as single application in a NoMachine custom session.

Note: the NoMachine product installed on the remote Linux server host must support the Linux virtual desktop functionality, e.g., Workstation, Terminal Server.

The following instructions have been tested in this environment:
- Hosting system: Ubuntu 18.04
- Docker version: 19.03.6
- NoMachine Workstation version: 7.0.211

How to run a NoMachine custom session
Connect by NoMachine to the Linux server host where you have installed a NoMachine product with support for the virtual Linux desktop functionality. In this example, Workstation has been installed. In the NoMachine client UI click on 'Create a new desktop or custom session'. Then click on 'Create a new custom session'.

In the 'Custom session' panel of the UI select the 'Run the following command' option and specify there the proper command to run the dockerized application on the Linux host. Examples in the next paragraphs provide also the command to be specified in this UI field.

Pre-requisites to run a dockerized application in a NoMachine custom session
- The remote host is Linux.
- Docker is installed on the host machine.
- A NoMachine server, e.g. NoMachine Workstation, is installed on the same host, but not in the Docker container.
- Instructions to set-up a dockerized application have to be executed in a terminal as normal user.

Step 1 - Get the browser-box Docker image.
Download the browser-box project at https://github.com/sameersbn/docker-browser-box by executing this command in a terminal::

Step 2 - Change directory to docker-browser-box and apply some manual configurations:

Modify the following line in the entrypoint.sh file:

exec sudo -HEu ${BROWSER_BOX_USER} PULSE_SERVER=/run/pulse/native $@ ${extra_opts}

to have:

exec sudo -HEu ${BROWSER_BOX_USER} PULSE_SERVER=/run/pulse $@ ${extra_opts}

In the scripts/browser-box script, substitute the following line:

VOLUMES+=" --volume=${XAUTH}:${XAUTH}"

with:

VOLUMES+=" --volume=$HOME/.Xauthority:${XAUTH}"

Remove the following line:

VOLUMES+=" --volume=/run/user/${USER_UID}/pulse:/run/pulse"

and add this line in place of the line above you have just removed:

VOLUMES+=" --volume=${PULSE_SERVER}:/run/pulse"

Substitute the following line:

${SUDO} docker run -d \

with:

${SUDO} docker run -d --net=host \

and:

${BROWSER_BOX_REPO}/browser-box:1.0.1-3 ${prog} $@ >/dev/null

with:

${BROWSER_BOX_REPO}/browser-box ${prog} $@ >/dev/null

Step 3 - Build the image:

Step 4 - Install scripts necessary to launch the browser
The following command will install the necessary scripts in the /usr/local/bin directory. Scripts will launch any of the following browsers: chromium-browser, firefox, google-chrome, google-chrome-stable, tor-browser:

Step 5 - Launch any of the available browsers
Browser can be launched by command line by using the 'browser-box ' command. For example, to launch google-chrome type the following command:

TIPS
I	In the "Run the following command" field of the NoMachine UI specify the 'browser-box ' command. For example to run Chrome as a single application with NoMachine, specify: browser-box google-chrome
II	If you need to uninstall scripts to run browsers in the docker container, execute the following command in a terminal:
$ docker run -it --rm \ --volume /usr/local/bin:/target \ sameersbn/browser-box uninstall
III	If you have problems with building browser-box image check value of TOR_VERSION variable in docker-browser-box/Dockerfile file. It's possible that version assigned here is older than versions of tor-browser available on https://dist.torproject.org/torbrowser/
IV	In case of problems with installing a public key for a repository, change line: && apt-key adv --fetch-keys "https://dl-ssl.google.com/linux/linux_signing_key.pub" \ to: && wget -q "https://dl-ssl.google.com/linux/linux_signing_key.pub" && apt-key add linux_signing_key.pub \ and: && gpg --keyserver hkp://ipv4.pool.sks-keyservers.net --recv-keys ${TOR_FINGERPRINT} \ && gpg --fingerprint ${TOR_FINGERPRINT} | grep -q "EF6E 286D DA85 EA2A 4BA7 DE68 4E2C 6E87 9329 8290" \ to: && wget -q https://openpgpkey.torproject.org/.well-known/openpgpkey/torproject.org/hu/kounek7zrdx745qydx6p59t9mqjpuhdf |gpg --import - \ && gpg --output ./tor.keyring --export 0xEF6E286DDA85EA2A4BA7DE684E2C6E8793298290 \ For more details please refer to: https://support.torproject.org/tbb/how-to-verify-signature/

Step 1- Get the LibreOffice Docker image.
Command below pulls down the LibreOffice docker image if it is not already available and runs it:

The same command can be also specified in the "Run the following command" field of the NoMachine UI to run LibreOffice in a NoMachine custom session. However it's more convenient to create a wrapper script like the following. Let's call it, for example, libreoffice.sh. Create the libreoffice.sh file with this content:

and give permissions to execute it by running from a terminal:

To run LibreOffice as a single application with NoMachine, specify this command in the "Run the following command" field of the GUI:
/path/to/your/home/libreoffice.sh

TIP

Terminating a custom session doesn't terminate a docker container. To terminate it you may use the docker kill <container ID> command.

Step 1 - Get the Skype Docker image
Command below pulls down the Skype Docker image if it is not already available and runs it:

The same command can be also specified in the "Run the following command" field of the NoMachine UI to run Skype in a NoMachine custom session. However it's more convenient to create a wrapper script like the following. Let's call it skype.sh. Create the skype.sh file with this content:

and give permissions to execute it by running from a terminal:

To run Skype as a single application with NoMachine, specify this command in the "Run the following command" field of the GUI:
/path/to/your/home/skype.sh

TIP

Terminating a custom session doesn't terminate a docker container. To terminate it you may use the docker kill <container ID> command.

Step 1 - Get the Thunderbird Docker image
Command below pulls down the Thunderbird Docker image if it is not already available and runs it:

The same command can be also specified in the "Run the following command" field of the NoMachine UI to run Thunderbird in a NoMachine custom session. However it's more convenient to create a wrapper script like the following. Let's call it thunderbird.sh. Create the thunderbird.sh file with this content:

and give permissions to execute it by running from a terminal:

To run Thunderbird as a single application with NoMachine, specify this command in the "Run the following command" field of the GUI:
/path/to/your/home/thunderbird.sh

TIP

Terminating a custom session doesn't terminate a docker container. To terminate it you may use the docker kill <container ID> command.