MAAS relies on a repository of OS images for machine deployment, called a SimpleStreams source. There are two streams: candidate and stable. The stable stream is fully tested, reliable, and generally considered production-ready. Candidate images are essentially pre-release images – they are newer, so they may have bugs or incomplete testing. Use the stable stream if you’re deploying machines in production, and candidate if you need support for a newer OS version that is not yet stable. MAAS defaults to stable if you do not make a choice.
Both contain either Ubuntu or CentOS, a bootloader, an initial RAMdisk filesystem, and release notifications. MAAS syncs images hourly at the region level. Rack controller syncs run every 5 minutes.
Switch image streams
You can switch streams at any time using these procedures:
UI
Images > Change source > Custom > set URL to:
- Candidate:
http://images.maas.io/ephemeral-v3/candidate - Stable:
maas.io
CLI
BOOT_SOURCE_ID=$(maas $PROFILE boot-sources read)
Manage images
Choose which images to keep locally. Images must be downloaded before they can be deployed.
UI
Main menu > Images > Select/Unselect > Save selection
CLI
maas $PROFILE boot-sources read # list boot sources
maas $PROFILE boot-source-selections create $SOURCE_ID \
os="ubuntu" release="$SERIES" arches="$ARCH" \
subarches="$KERNEL" labels="*" # select boot sources
maas $PROFILE boot-resources read # list images
maas $PROFILE boot-resources import # select images
Additional CLI management commands
Delete a boot source
maas $PROFILE boot-source delete $SOURCE_ID
Update a boot source
maas $PROFILE boot-source update $SOURCE_ID \
url=$URL keyring_filename=$KEYRING_FILE
Add a new boot source
maas $PROFILE boot-sources create \
url=$URL keyring_filename=$KEYRING_FILE
Use /usr/share/keyrings/ubuntu-cloudimage-keyring.gpg as the keyring file.
Use a custom mirror
UI
- Images > Change source > Custom > enter URL > Connect.
- For advanced options, select Show advanced options.
- Set up a local mirror (below) for faster imports.
Use a local mirror
A local mirror can improve image sync performance.
Install SimpleStreams
Start by installing SimpleStreams:
sudo apt install simplestreams
Define helper variables
Define these variables for cleaner CLI commands:
KEYRING_FILE=/usr/share/keyrings/ubuntu-cloudimage-keyring.gpg
IMAGE_SRC=https://images.maas.io/ephemeral-v3/stable
IMAGE_DIR=/var/www/html/maas/images/ephemeral-v3/stable
Mirror your kernels
Mirror your kernels with these commands:
sudo sstream-mirror --keyring=$KEYRING_FILE $IMAGE_SRC $IMAGE_DIR 'arch=amd64' 'release~(bionic|focal)' --max=1 --progress
sudo sstream-mirror --keyring=$KEYRING_FILE $IMAGE_SRC $IMAGE_DIR 'os~(grub*|pxelinux)' --max=1 --progress
Use --dry-run to preview your selection.
MAAS saves images to the directory defined by ‘IMAGE_DIR’. The new boot source URL will be http://<myserver>/maas/images/ephemeral-v3/stable/.
Verify image availability at the URL above. Regularly update your mirror with cron to fetch the latest images.
Set URL=https://$MIRROR/maas/images/ephemeral-v3/stable/ and KEYRING_FILE=/usr/share/keyrings/ubuntu-cloudimage-keyring.gpg, where $MIRROR is the mirror server.
Last updated 3 days ago.