Bug Reference

CLOUDSTACK-6122

Introduction

Purpose

LXC support was added to CloudStack in 4.2 release. FS : LXC Support in Cloudstack. The objective of this feature is to enhance LXC support by adding more functionality. This document contains design specification of the enhancements.

References

LXC Support in Cloudstack

CLOUDSTACK-922

Feature Specifications

LXC was implemented as hypervisor in cloudstack. Following operations are currently supported:

• Add an LXC cluster 
• Add an LXC host 
• Register an LXC template 
• Spin up an LXC container

LXC containers are created using libvirt in cloudstack. Libvirt domain xml will be modified to support additional features. KVM system Vms are used for LXC, so most of the networking features are already supported.

Storage

• DATA disk: Support data disk while creating container. 
• Support attach/detach disk. attach-disk and detach-disk are supported by libvirt (since 1.0.2) for lxc. Same will be leveraged to support attach/detach data volume.
• Support Ceph storage that will appear as block device on host using RBD

  • Configure and create Ceph RBD on host and make it visible in the container using host passthrough configuration

  • <hostdev mode='capabilities' type='storage'>
       <source>
          <block>/dev/rbd1</block>
        </source>
    </hostdev>

• Migrate volume of a stopped container. Container root volume will be migrated across primary storages by copying compressed tar.gz of the root file system. 

Template

Registering a template and  Launching container from template is already supported. Additional functionality:

• Create template from ROOT volume. Template is a compressed tar.gz of the root file system. Create template from volume will copy the tar.gz of the root file system to secondary storage.

ISO

• Register an ISO: Register an ISO and download on to secondary storage
• Attach/Detach an ISO to a container: Involves copying the ISO from secondary to primary and the attached the ISO to container by mounting (using attach-device).
• Launch container from ISO: Mount ISO image as rootfs for container
  
  

Console Access

CLOUDSTACK-4990

Below libvirt doesn't seem to work for LXC. autoport option did not assign a port.

<graphics type="vnc" port="-1" autoport="yes" listen="10.147.28.11" keymap="en-us"/>

Database

No changes

New APIs

None

Limitations

Open Issues

Min required libvirt version should be documented