Tutorial

Installing LXCM

To install LXCM, download it and run lxcm install. You can also install the Debian package.

git clone https://github.com/iwalton3/lxcm
cd lxcm
bash lxcm install

This will install all dependencies and configure the system to manage
containers.

Getting Help

LXCM has a built-in help command feature listing command syntax. To
access it, simply run the program without arguments:

lxcm

LXCM also has full support for tab completion. To get a list of commands
or suggestions, press the tab key twice.

Creating Containers Quickly

If you want to create a container and set it up using a menu interface
instead of the command line, issue this command and a wizard will guide
you through the process of setting up the container (and any templates).

lxcm ez

Creating a Template

To create a basic debian template for the exercises, run:

lxcm template debian debian

To get a listing of templates, run:

lxcm list-templates

Creating Containers

Create a new container, called mysql. Start the container and get a
shell.

lxcm new debian mysql
lxcm start mysql
lxcm shell mysql

You are now in a shell within the container. Install mysql using the
following command:

apt install mysql-server
service mysql start
mysql
CREATE USER 'test'@'%';
CREATE DATABASE testdb;
GRANT ALL PRIVILEGES ON testdb.* TO 'test'@'%' IDENTIFIED BY
'changeme';
[CTRL+D]

You are now running mysql in a container, but mysql needs to be
reconfigured to listen to network connections. To do that, enter this
command to install a text editor and edit the mysql configuration:

apt install vim
vim /etc/mysql/mariadb.conf.d/50-server.cnf

Find the bind-address directive (enter /bind) and change it to 0.0.0.0.
Then restart mysql and exit:

service mysql restart
[CTRL+D]

To ensure mysql starts with the container, run:

lxcm edit-startup mysql

Then add this line to the startup configuration:

service mysql start

(The default editor for lxcm is vim. You need to press i to insert, then
ESC :x ENTER to quit. You can also set the EDITOR environment variable
to something else, if you prefer another editor.)

To forward traffic into the container, use a port forward:

lxcm forward add tcp 3306 3306 mysql all

We are using a port forward of type “all” in this example. You can use
“private” to allow connections from other containers, or “public” to
allow connections from other computers on the network.

To confirm the mysql server works, install a mysql client and connect to
the database.

apt install mysql-client
ip a
mysql -h [your ip address] -u test -p

(Enter the password set earlier, which was changeme.)

Creating and Restoring Backups

To create a backup of the mysql container, enter this command:

lxcm backup mysql backup1

The backup, in this case is saved in
“/var/lib/lxcm/containers/mysql/backups/backup1.sfs”. The backup only
contains the changes from the template.

Let’s say someone decides to make pain for you. In this case, they
decided to delete everything:

lxcm execute mysql rm -rfv --no-preserve-root /

To recover from this, simply restore the backup:

lxcm restore mysql backup1
lxcm start mysql

You will be asked if you want to create a backup of the damaged system
first. This may be useful for analysis later.

Other Tips

Restarting Containers

To restart the mysql container, run:

lxcm restart mysql

Copying Files To and From Containers

You can use the put and get commands to copy files into and out of containers.

lxcm put mysql my-new-file-database.sql
lxcm get mysql /etc/passwd

Restoring Backups to Other Containers

If you want to investigate what happened to a system without having to
keep it down, after restoring the system you can investigate it by
mounting the backup. Follow these steps:

lxcm shell mysql
echo "echo YOU HAVE A VIRUS" >> ~/.bashrc
[CTRL+D]
lxcm restore backup1 mysql
lxcm start mysql
(Enter y for “create backup first”.)
lxcm inspect mysql "[backup name]”

Now you can examine the system without interrupting the original mysql
container.

Migrating a System over SSH

If you have an existing system and you want to make it into a container,
you can migrate it over SSH. Make sure the system has SSH as root
enabled, then run the following:

lxcm migrate [system ip] [template name]
lxcm new [template name] [container name]

If you would like to save space, run this command before creating the
container:

lxcm compress [template name]

You can also compress a template after creating a container, but you
must restart the containers for the operation to take effect.

Create a Template from a Container

Suppose you want to create many more mysql servers. To make a template
that includes the mysql configuration, enter this command:

lxcm compose mysql mysql-template

Firewall Policies

The container system can also manage firewall policies for the
containers and the host, by generating iptables rules based on a custom
syntax. See the lxcm help page and manual for details.

Creating Containers (Wizard)

The lxcm utility now includes an command called ez. When run, this allows you to make new containers by answering a series of questions. If a template is needed to create a container, you can create it using the wizard as well.

lxcm ez

Try creating a simple debian container running the apache web server.

Using Tab Completion

The command line now has support for tab completion. Use tab at any time while typing commands or options to get suggestions. Tab completion can considerably reduce the amount of time it takes to use the utility.

Copying Files

In the past, you used to need to deal with the special filesystems to copy files into and out of containers. Now there is a command that allows this to be done. It even supports tab completion for files inside containers.

lxcm put mysql my-new-file-database.sql
lxcm get mysql /etc/passwd

Autostart

You can configure a container to start with your computer. To do so, use the autostart command:

lxcm autostart [container name] manual/auto

Inspecting Backups

In the past, you needed to restore a backup to another container to be able to look at it without service downtime. Now you can mount a container backup read-only for your investigation needs:

lxcm inspect mysql "[backup name]”