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.
- tags
- Comma-delimited tags assigned to the machine. Currently only supported by MaaS.
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. See "tags" above.
- os-scheduler-hints
- Experimental constraint exposing Openstack-specific scheduler hints features. Do not use.