5.0 KiB
Octavia Base Image
Launchpad blueprint:
https://blueprints.launchpad.net/octavia/+spec/base-image
Octavia is an operator-grade reference implementation for Load Balancing as a Service (LBaaS) for OpenStack. The component of Octavia that does the load balancing is known as amphora. Amphora may be a virtual machine, may be a container, or may run on bare metal. Creating images for bare metal amphora installs is outside the scope of this 0.5 specification but may be added in a future release.
Amphora will need a base image that can be deployed by Octavia to provide load balancing.
Problem description
Octavia needs a method for generating base images to be deployed as load balancing entities.
Proposed change
Leverage the OpenStack diskimage-builder project [1] tools to provide a script that builds qcow2 images or a tar file suitable for use in creating containers. This script will be modeled after the OpenStack Sahara [2] project's diskimage-create.sh script.
This script and associated elements will build Amphora images. Initial support with be with an Ubuntu OS and HAProxy. The script will be able to use Fedora or CentOS as a base OS but these will not initially be tested or supported. As the project progresses and/or the diskimage-builder project adds support for additional base OS options they may become available for Amphora images. This does not mean that they are necessarily supported or tested.
The script will use environment variables to customize the build beyond the Octavia project defaults, such as adding elements.
The initial supported and tested image will be created using the diskimage-create.sh defaults (no command line parameters or environment variables set). As the project progresses we may add additional supported configurations.
Command syntax:
[-a i386 | amd64 | armhf ]
[-b haproxy ]
[-c ~/.cache/image-create | <cache directory> ]
[-i ubuntu | fedora | centos ]
[-o amphora-x64-haproxy | <filename> ]
[-t qcow2 | tar ]
[-s 5 | <size in GB> ]
'-a' is the architecture type for the image (default: amd64)
'-b' is the backend type (default: haproxy)
'-c' is the path to the cache directory (default: ~/.cache/image-create)
'-i' is the base OS (default: ubuntu)
'-o' is the output image file name
'-t' is the image type (default: qcow2)
'-s' is the image size to produce in gigabytes (default: 5)
BASE_OS_MIRROR - URL to a mirror for the base OS selected (-i).
DIB_REPO_PATH - Path to the diskimage-builder repository (default: ../../diskimage-builder)
DIB_ELEMENTS - Override the elements used to build the image
DIB_LOCAL_ELEMENTS - Elements to add to the build (requires DIB_LOCAL_ELEMENTS_PATH be specified)
DIB_LOCAL_ELEMENTS_PATH - Path to the local elements directory
Container support
The Docker command line required to import a tar file created with this script is [3]:
$ docker import - image:amphora-x64-haproxy < amphora-x64-haproxy.tarAlternatives
Deployers can manually create an image or container, but they would need to make sure the required components are included.
Data model impact
None
REST API impact
None
Security impact
None
Notifications impact
None
Other end user impact
None
Performance Impact
None
Other deployer impact
This script will make creating an Octavia Amphora image or container simple.
Developer impact
None
Implementation
Assignee(s)
Michael Johnson <johnsom>
Work Items
- Write diskimage-create.sh script based on Sahara project's script.
- Identify the list of packages required for Octavia Amphora.
- Create required elements not provided by the diskimage-builder project.
- Create unit tests
Dependencies
This script will depend on the OpenStack diskimage-builder project.
Testing
Initial testing will be completed using the default settings for the diskimage-create.sh tool.
- Unit tests with tox
-
- Validate that the image is the correct size and mounts via loopback
- Check that a valid kernel is installed
- Check that HAProxy and all required packages are installed
- tempest tests