Difference between revisions of "LXD"

Revision as of 11:30, August 12, 2017

LXD is a container "hypervisor" it should provide user with a new and fresh experience using LXC technology.

LXD consists of three components:

A system-wide daemon (lxd)
A command line client (lxc)
An OpenStack Nova plugin (nova-compute-lxd)

A REST API that is accesible both locally and if enabled, over the network is provided from the lxd daemon.

The command line tool is designed to be a very simple, yet very powerful tool to manage all your containers. It can handle connections to multiple container hosts and easily give you an overview of all the containers on your network, let you create some more where you want them and even move them around while they're running.

The OpenStack plugin then allows you to use your lxd hosts as compute nodes, running workloads on containers rather than virtual machines.

The LXD project was founded and is currently led by Canonical Ltd and Ubuntu with contributions from a range of other companies and individual contributors.

Features

Some of the biggest features of LXD are:

Secure by design (unprivileged containers, resource restrictions and much more)
Scalable (from containers on your laptop to thousand of compute nodes)
Intuitive (simple, clear API and crisp command line experience)
Image based (no more distribution templates, only good, trusted images)
Live migration

Relationship with LXC

LXD isn't a rewrite of LXC, in fact it's building on top of LXC to provide a new, better user experience. Under the hood, LXD uses LXC through liblxc and its Go binding to create and manage the containers.

It's basically an alternative to LXC's tools and distribution template system with the added features that come from being controllable over the network.

Licensing

LXD is free software and is developed under the Apache 2 license.

Installing LXD in Funtoo

Kernel pre-requisities

These options should be enable in your kernel to use all of the functions of LXD:

 !GRKERNSEC_CHROOT_CAPS
 !GRKERNSEC_CHROOT_CHMOD
 !GRKERNSEC_CHROOT_DOUBLE
 !GRKERNSEC_CHROOT_MOUNT
 !GRKERNSEC_CHROOT_PIVOT
 !GRKERNSEC_PROC
 !GRKERNSEC_SYSFS_RESTRICT
 !NETPRIO_CGROUP
 BRIDGE
 CGROUP_CPUACCT
 CGROUP_DEVICE
 CGROUP_FREEZER
 CGROUP_SCHED
 CGROUPS
 CHECKPOINT_RESTORE
 CPUSETS
 DEVPTS_MULTIPLE_INSTANCES
 DUMMY
 EPOLL 
 EVENTFD 
 FHANDLE 
 IA32_EMULATION 
 INET_DIAG 
 INET_TCP_DIAG
 INET_UDP_DIAG
 INOTIFY_USER
 IP_NF_NAT
 IP_NF_TARGET_MASQUERADE
 IP6_NF_NAT
 IP6_NF_TARGET_MASQUERADE
 IPC_NS
 IPV6
 MACVLAN
 NAMESPACES 
 NET_IPGRE
 NET_IPGRE_DEMUX
 NET_IPIP
 NET_NS
 NETFILTER_XT_MATCH_COMMENT
 NETLINK_DIAG
 NF_NAT_MASQUERADE_IPV4
 NF_NAT_MASQUERADE_IPV6
 PACKET_DIAG 
 PID_NS 
 POSIX_MQUEUE
 UNIX_DIAG
 USER_NS
 UTS_NS
 VETH
 VXLAN

Getting LXD

root # emerge -av lxd

These are the packages that would be merged, in order:

Calculating dependencies... done!
[ebuild  N     ] dev-lang/go-1.8-r1:0/1.8::gentoo  USE="-gccgo" 69,062 KiB
[ebuild  N     ] dev-go/go-crypto-0_pre20160126:0/0_pre20160126::gentoo  881 KiB
[ebuild  N     ] sys-fs/squashfs-tools-4.3-r2::gentoo  USE="xattr xz -debug -lz4 -lzma -lzo -static" 194 KiB
[ebuild  N     ] sys-libs/libseccomp-2.3.2::gentoo  USE="-static-libs" 547 KiB
[ebuild  N     ] net-libs/libnet-1.2_rc3-r1:1.1::gentoo  USE="-doc -static-libs" 661 KiB
[ebuild  N     ] dev-libs/libnl-3.3.0_rc1:3::gentoo  USE="python -static-libs -utils" PYTHON_TARGETS="python2_7 python3_4 -python3_5" 912 KiB
[ebuild  N     ] dev-python/ipaddr-2.1.11-r1::gentoo  PYTHON_TARGETS="python2_7 python3_4 -pypy -python3_5" 29 KiB
[ebuild  N     ] dev-go/go-text-0_pre20160211:0/0_pre20160211::gentoo  3,922 KiB
[ebuild  N     ] sys-libs/libcap-2.25::gentoo  USE="pam -static-libs" 63 KiB
[ebuild  N     ] dev-go/go-net-0_pre20160216:0/0_pre20160216::gentoo  724 KiB
[ebuild  N     ] net-dns/dnsmasq-2.76-r1::gentoo  USE="dhcp inotify ipv6 nls -auth-dns -conntrack -dbus -dhcp-tools -dnssec -idn -lua -script (-selinux) -static -tftp" LINGUAS="-de -es -fi -fr -id -it -no -pl -pt_BR -ro" 470 KiB
[ebuild  N     ] dev-libs/protobuf-c-1.2.1-r1:0/1.0.0::gentoo  USE="-static-libs {-test}" 448 KiB
[ebuild  N     ] sys-process/criu-2.12::gentoo  USE="python -setproctitle" PYTHON_TARGETS="python2_7" 632 KiB
[ebuild  N     ] app-emulation/lxc-2.0.7::gentoo  USE="python seccomp -cgmanager -doc -examples -lua" PYTHON_TARGETS="python3_4 -python3_5" 774 KiB
[ebuild  N     ] app-emulation/lxd-2.11::gentoo  USE="daemon nls {-test}" LINGUAS="-de -el -fr -ja -nl -ru" 2,352 KiB

Total: 15 packages (15 new), Size of downloads: 81,664 KiB

Would you like to add these changes to your config files? [Yes/No]

Running LXD

Once installed you need to start the LXD daemon. By running:

root # service lxd start
 * Starting lxd server ...

First setup of LXD/Initialisation

Before using LXD for the first time as a user, you may initialize your LXD environment:

user $ lxd init
Do you want to configure a new storage pool (yes/no) [default=yes]?
Name of the new storage pool [default=default]:
Name of the storage backend to use (dir, btrfs, lvm) [default=dir]: btrfs
Create a new BTRFS pool (yes/no) [default=yes]?
Would you like to use an existing block device (yes/no) [default=no]?
Would you like to create a new subvolume for the BTRFS storage pool (yes/no) [default=yes]:
Would you like LXD to be available over the network (yes/no) [default=no]?
Would you like stale cached images to be updated automatically (yes/no) [default=yes]?
Would you like to create a new network bridge (yes/no) [default=yes]?
What should the new bridge be called [default=lxdbr0]?
What IPv4 address should be used (CIDR subnet notation, “auto” or “none”) [default=auto]?
What IPv6 address should be used (CIDR subnet notation, “auto” or “none”) [default=auto]?
LXD has been successfully configured.

What this does is it creates btrfs subvolumes like this:

user $ btrfs sub list .
ID 260 gen 1047 top level 5 path rootfs
ID 280 gen 1046 top level 260 path var/lib/lxd/storage-pools/default
ID 281 gen 1043 top level 280 path var/lib/lxd/storage-pools/default/containers
ID 282 gen 1044 top level 280 path var/lib/lxd/storage-pools/default/snapshots
ID 283 gen 1045 top level 280 path var/lib/lxd/storage-pools/default/images
ID 284 gen 1046 top level 280 path var/lib/lxd/storage-pools/default/custom