Constraints
Complete listing of constraints supported by juju and what they mean. See using constraints for how to specify these in a deployment.
Generic constraints
- arch
- Short name of architecture that a service must run on. Can be left blank to indicate any architecture is acceptable, or one of
amd64
,arm
, ori386
. - container
- Name of container type that a service unit must run inside. Can be left blank to indicate no preference, or one of
none
for uncontainerised,lxc
, orkvm
. - cpu-cores
- Minimum number of effective CPU cores that must be available to a service unit.
- cpu-power
- Minimum amount of abstract CPU power that must be available to a service unit, where 100 units is roughly equivalent to "a single 2007-era Xeon" as reflected by 1 Amazon ECU. Warning: Not all providers support this constraint, use
cpu-cores
for portability. - mem
- Minimum number of megabytes of RAM that must be available to a service unit. An optional suffix of M/G/T/P indicates the value is mega-/giga-/tera-/peta- bytes.
- root-disk
- Minimum amount of of disk space on the root drive on each service unit. Additional storage that may be attached separately does not count towards this value.
Legacy constraints
In pre-1.0 juju some additional or differently named constraints were also supported, these need to be migrated when upgrading.
- cpu
- Number of CPU cores for most providers, but equivalent to an Amazon ECU on AWS. Use
cpu-cores
instead. - instance-type
- Cloud-specific instance-type name that a service used must be deployed on. Valid values vary by provider, and individual deployment in some cases. Use appropriate values for
cpu-count
,mem
, androot-disk
instead where possible for portability. - ec2-zone
- EC2 availability zone that a service unit must be deployed into. No equivalent implemented as of juju 1.12, follow bug 1183831.
- maas-name
- Specific MAAS machine name that a service unit must be deployed on. Use
maas-tags
instead by preference. - maas-tags
- List of tags a MAAS machine must have for a service unit to be deployed on. No equivalent implemented as of juju 1.12, follow bug 1170337.
- os-scheduler-hints
- Experimental constraint exposing Openstack-specific scheduler hints features. Do not use.