Demonstration on LXC containers

1. Demonstration on LXC containers
   1. Resources
   2. Creating a LXC container
   3. Launch a command on the container
      1. Get a bash on the container
   4. Stop the container and restart it
   5. Snapshot of the container and restoration

Resources

This demonstration directly uses a subpart of the content of the online try of LXC/LXD at this link. Please go to the corresponding link and start the online try.

Creating a LXC container

1. lxc image list No images are currently available on the host OS.

2. lxc launch images:ubuntu/18.04 first This command starts a container called “first” using the Ubuntu 18.04 image.

3. lxc list Your new container is listed in the list of containers.

4. lxc image list The ubuntu/18.04 is now listed in the list of known images.

5. lxc info first Get some info on your container.

Launch a command on the container

1. lxc exec first -- apt-get update and lxc exec first -- apt-get install sl -y These commands respectively execute the command apt-get update and apt-get install sl -y in your container. The package sl is a well known ASCII train application on Linux. Let’s try it!

2. lxc exec first -- /usr/games/sl Did you see the train?

Get a bash on the container

1. lxc exec first -- bash Now you should see root@first:~#. This means that you’re having a bash directly on your container!

2. mkdir test and touch test/toto.org and ls test/ You’ve just created a directory test and a org file in it toto.org. If you don’t know emacs-org mode, take a look! It could be helpful to handle your thesis project in a light way! (bibliography management, daily TODO lists, agenda, reproducible research and much more!)

Stop the container and restart it

1. exit You’ve quit the bash on your container.

2. lxc stop first You’ve stopped your container.

3. lxc start first You’ve started it again.

4. lxc exec first -- /usr/games/sl and lxc exec first -- ls test/ You’ve checked that your new package sl and your new file are still there!

Snapshot of the container and restoration

1. lxc snapshot first clean You’ve just created a snapshot from your running container first under the name clean.

2. lxc exec first -- rm -Rf /etc /usr Oups! You’ve just deleted a very important part of the Linux OS!

3. lxc exec first -- bash Ohhh no! Your bash is broken!

4. exit

5. lxc restore first clean Ok it seems to work to restore the first container!

6. lxc exec first -- bash and ls test/ YES!