See also: Unit
This document demonstrates various operations that you can perform on a unit.
- Add a unit
- Control the number of units
- Show details about a unit
- List a unit’s resources
- Show the status of a unit
- Set the meter status on a unit
- Mark unit errors as resolved
- Remove a unit
To add a unit, use the
add-unit command followed by the application name:
This is only true for machine deployments. For Kubernetes, see How to controller the number of units.
juju add-unit mysql
By using various command options, you can also specify the number of units, the model, the kind of storage, the target machine (e.g., if you want to collocate multiple units of the same or of different applications on the same machine – though watch out for potentials configuration clashes!), etc.
The procedure depends on whether you are on machines or rather Kubernetes.
Machines. To control the number of an application’s units in a machine deployment, add or remove units in the amount required to obtain the desired number.
Kubernetes. To control the number of an application’s units in a Kubernetes deployment, run the
scale-application command followed by the number of desired units (which can be both higher and lower than the current number).
juju scale-application mediawiki 3
To see more details about a unit, use the
show-unit command followed by the unit name:
juju show-unit mysql/0
By using various options you can also choose to get just a subset of the output, a different output format, etc.
To see the resources for a unit, use the
resources command followed by the unit name. For example:
juju resources mysql/0
To see the status of a unit, use the
This will show information about the model, along with its machines, applications and units. For example:
Model Controller Cloud/Region Version SLA Timestamp
tutorial-model tutorial-controller microk8s/localhost 2.9.34 unsupported 12:10:16+02:00
App Version Status Scale Charm Channel Rev Address Exposed Message
mattermost-k8s .../mattermost:v6.6.0-20.04... active 1 mattermost-k8s stable 21 10.152.183.185 no
postgresql-k8s .../postgresql@ed0e37f active 1 postgresql-k8s stable 4 no Pod configured
Unit Workload Agent Address Ports Message
mattermost-k8s/0* active idle 10.1.179.151 8065/TCP
postgresql-k8s/0* active idle 10.1.179.149 5432/TCP Pod configured
To set the meter status on a unit, use the
set-meter-status command followed by the unit name. For example:
juju set-meter-status myapp/0
To mark unit errors as resolved, use the
resolved command followed by the unit name or a list of space-separated unit names. For example:
juju resolved myapp/0
To remove individual units instead of the entire application (i.e. all the units), use the
remove-unit command followed by the unit name. For example, the code below removes unit 2 of the PostgreSQL charm. For example:
While this can be used for both machine and Kubernetes deployments, unless you care about which unit you’re removing specifically, in Kubernetes you may also just run
juju scale-application <n>, where
n is less than the current number of units. See How to control the number of units.
juju remove-unit postgresql/2
In the case that the removed unit is the only one running, the corresponding machine will also be removed, unless any of the following is true for that machine:
- it was created with
- it is not being used as the only controller
- it is not hosting Juju-managed containers (KVM guests or LXD containers)
It is also possible to remove multiple units at a time by passing instead a space-separated list of unit names:
juju remove-unit mediawiki/1 mediawiki/3 mediawiki/5 mysql/2
To also destroy the storage attached to the units, add the
As a last resort, use the
--force option (in