How to install LXD container hypervisor on Ubuntu 16.04 LTS server

LXD Container:-
LXD is a lightweight open source hypervisor, It allows you to create multiple Container on a single machine or Virtual machine also. Where you can run multiple application, services without extra cost And without modifying core server application package. 

i.e. you are working in a hosting provider or Software development company, Where you need multiple version of  PHP, MySQL and Apache etc.. but you don't want to modify existing installation because it can interrupt current running application. For such requirement, you can use LXD container.

 LXD System requirement:
 One working PC with Ubuntu 16.04 LTS

Required Software packages:
1- LXD
2- zfsutils-linux
3- bridge-utils 


Step-1: Install LXD

root@Server16:~# apt install lxd

Step-2: Install zfsutils-Linux
ZFSUtils-Linux is required to create ZFS file system to store LXD Container, for ZFS file system we can use the same partition or can use another HDD.

Use command below to Install Zfsutils-linux

root@Server16:~# apt install zfsutils-linux

Step-3:  Install bridge-utils
we required this package to setup network bridge interface so that container's interface can get IP and can communicate with Public network.

Use command below to install this package.

root@Server16:~# apt install bridge-utils

Step-4: Create Bridge network interface.
 Modify your network Interface and it should look like below.

Change your Primary network interface to Manual and bind it with bridge network.

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

source /etc/network/interfaces.d/*

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
#auto enp0s3
iface enp0s3 inet manual
# Bridge Network Interface
auto br0
iface br0 inet dhcp
        bridge-ports enp0s3
        bridge-ifaces enp0s3
# Secondary Network Interface
auto enp0s8
iface enp0s8 inet dhcp

Save and Exit from the file.

Step-5: Restart your br0 network interface 

root@Server16:~# ifdown enp0s3 && ifup enp0s3 && ifup br0

Please Note: - If you don't see reply from bridge interface, Please restart your server once.

Check your network interface and IP address status using command below.

root@Server16:~# ifconfig
br0       Link encap:Ethernet  HWaddr 08:00:27:ab:3c:75
          inet addr:192.168.28.120  Bcast:192.168.28.255  Mask:255.255.255.0
          inet6 addr: fe80::a00:27ff:feab:3c75/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:337 errors:0 dropped:0 overruns:0 frame:0
          TX packets:141 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:30299 (30.2 KB)  TX bytes:17098 (17.0 KB)

enp0s3    Link encap:Ethernet  HWaddr 08:00:27:ab:3c:75
          inet6 addr: fe80::a00:27ff:feab:3c75/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:398 errors:0 dropped:0 overruns:0 frame:0
          TX packets:149 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:40161 (40.1 KB)  TX bytes:17866 (17.8 KB)

enp0s8    Link encap:Ethernet  HWaddr 08:00:27:9f:86:47
          inet addr:10.0.2.5  Bcast:10.0.2.255  Mask:255.255.255.0
          inet6 addr: fe80::a00:27ff:fe9f:8647/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:7 errors:0 dropped:0 overruns:0 frame:0
          TX packets:15 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:1988 (1.9 KB)  TX bytes:1720 (1.7 KB)

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:80 errors:0 dropped:0 overruns:0 frame:0
          TX packets:80 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1
          RX bytes:5920 (5.9 KB)  TX bytes:5920 (5.9 KB)

root@Server16:~#

Step-6: Complete LXD configuration -
During the LXD configuration wizard  It will ask to configure bridge interface, Select No when it ask for auto and choose no to give bridge interface manually.

root@Server16:~# lxd init
Name of the storage backend to use (dir or zfs) [default=zfs]: zfs
Create a new ZFS pool (yes/no) [default=yes]? yes
Name of the new ZFS pool [default=lxd]: zfs-pool
Would you like to use an existing block device (yes/no) [default=no]? no
Size in GB of the new loop device (1GB minimum) [default=15]: 10
Would you like LXD to be available over the network (yes/no) [default=no]? no
Do you want to configure the LXD bridge (yes/no) [default=yes]? yes
Warning: Stopping lxd.service, but it can still be activated by:
  lxd.socket
LXD has been successfully configured.
root@Server16:~#

Configuration part has been completed successfully.


Step-7: Create your first Container using the command below.

root@Server16:~# lxc launch ubuntu:xenial C1
Creating C1
Starting C1
root@Server16:~#

 

Your first container is ready, let's check container status using command bellow.

 

root@Server16:~# lxc list
+------+---------+-----------------------+------+------------+-----------+
| NAME |  STATE  |         IPV4          | IPV6 |    TYPE    | SNAPSHOTS |
+------+---------+-----------------------+------+------------+-----------+
| C1   | RUNNING | 192.168.28.121 (eth0) |      | PERSISTENT | 0         |
+------+---------+-----------------------+------+------------+-----------+
root@Server16:~#

!!! Congrats, You have successfully configured LDX hypervisor !!!

**Some other useful command to work with LXD**

1- Command  login to LXD container:

root@Server16:~# lxc exec C1 /bin/bash
root@C1:~#

2- By default you can't login to container using password from a remote PC because 

"PasswordAuthentication  no" not allowed from sshd_conf file. 

Let's modify this file to access via ssh from remote pc.

 

root@C1:~# vi /etc/ssh/sshd_config

And modify passwordaAthentication file like below.

# To enable empty passwords, change to yes (NOT RECOMMENDED)
PermitEmptyPasswords no

# Change to yes to enable challenge-response passwords (beware issues with
# some PAM modules and threads)
ChallengeResponseAuthentication no

# Change to no to disable tunnelled clear text passwords
PasswordAuthentication yes

# Kerberos options
#KerberosAuthentication no
#KerberosGetAFSToken no
#KerberosOrLocalPasswd yes
#KerberosTicketCleanup yes

Save file and restart ssh service.

root@C1:~# /etc/init.d/ssh restart
[ ok ] Restarting ssh (via systemctl): ssh.service.