# FAQ

# Does Kontain run Docker containers without modifications?

Yes, it runs Docker containers without any modifications securely.

But if you would like more benefits, you can leverage Kontain's smaller resources/image sizes capabilities with a little bit more effort in your Dockerfile construction, and can also use its instant start capabilities for your slower containers.

# How do I run a Docker Container using Kontain?

Kontain runs whenever used as a runtime in docker or Kubernetes. The following is an example of this:

$ docker run -runtime=krun hello-world

Here is an example of Kontain in docker-compose, and in Kubernetes

# Which languages does it support?

The Default is English (United States), but it is not language dependent, so should work anywhere where Docker or Kubernetes works.

# Can it run on my desktop?

Yes, you can with the following Linux Operating Systems. If you are running Ubuntu 20.04 or above or Fedora 34 or above or Amazon Linux 2 with Kernel version 5.10 or above, it is very easy to install Kontain.

If you ensure that you have docker pre-installed, you can just use:

$ curl -s https://raw.githubusercontent.com/kontainapp/km/current/km-releases/kontain-install.sh | sudo bash

For more detailed instructions, you can refer to this link.

For running on a Windows 10 or above desktop, you can use Vagrant with Hyper-V as outlined here

For running on a Mac OS desktop, you can use brew to install Vagrant and install Kontain as outlined here

# How does it work?

Kontain works by adding a secure CRI-compliant Container runtime to Containerd, that is used by both Docker and Kubernetes to run containers.

By working with Containerd, the user just has to specify –runtime=krun in Docker or runtime:kontain in Kubernetes for a container to run in Kontain alongside other containers.

# Where can I use it or What platforms does it run on?

Kontain runs anywhere that Linux, Docker and Kubernetes runs, including AWS, Azure and Google Cloud and on-premises installations. It can be installed as a secure runtime for Docker/Containerd in desktops, VMs, Kubernetes.

# Is it easy to install?

As seen above, so long as you are running the requisite OS with KVM enabled and docker installed, it is very easy to install.

# How do I use it easily in 2 minutes?

Once you have it installed as shown above, you can use it to run a docker container as shown below:

$ docker run -runtime=krun hello-world

# Why should I use it over Docker for running my container?

Kontain:

secures a container with VM-level hardware isolation
provides smaller images thus consuming less resources,
without changing your CI/CD workflow/tools.
In addition, it provides instant start capabilities for your slow starting Docker containers.
Also, it runs alongside Docker containers in Docker-compose and Kubernetes, hence you can try out Kontain incrementally.

# Does it work with docker-compose?

Yes, you just have to add the line “runtime: krun” to docker-compose.yaml file. Here’s an example of Kontain in a docker-compose.yml file. It can run side by side with existing Docker containers, so you don’t have to run Here’s an example of Kontain in a Kubernetes manifest. It runs side by side with Docker containers.

# Is it open source?

Yes

# Is it free to try and use?

Yes