In Juju, a placement directive is an option based on the --to flag that can be passed to certain commands to specify a deploy location, where the commands include add-machine , add-unit , bootstrap , deploy , enable-ha and the location is (1) an existing or a new machine ID or (2) a key-value pair specifying a subnet, system ID, or an availability zone.
Example: juju add-machine --to 1, juju deploy --to zone=us-east-1a
The rest of this document gives details about the locations.
When the location is a key-value pair, its availability and meaning may vary from cloud to cloud. For details see List of supported clouds > <cloud name>.
Contents:
List of placement directive locations
<machine>
The machine ID.
Examples: 1 (existing machine 1), lxd:5 (new container on machine 5), 5/lxd/0 (existing container 0 on machine 5)
See more: Machine designations
subnet=<subnet>
Available for Azure and AWS EC2.
system-id=<system ID>
Available for MAAS.
zone=<zone>
Purpose: To specify an availability zone.
The zone placement directive may be used to override a zones constraint.
Example: zone=us-east-1a