How to deploy a charm

This document shows how to deploy a charm. In the context of charm development, this always follows the procedure for a local charm, but the specifics vary depending on whether it’s the first time you’re deploying or if you’re rather updating your deployment by updating the charm.

To catch any issues that may arise during deployment: Before you deploy:

# Set your logging verbosity level to `DEBUG`:
$ juju model-config logging-config="<root>=WARNING;unit=DEBUG"

# Start a live debug session:
$ juju debug-log

See more: Juju | Model configuration keys > logging-config, Juju | debug-log

Deploy a local charm for the first time

Then, to deploy a local charm for the first time, after packing the charm, run the juju deploy command followed by the path to the .charm file and, if applicable, the --resource flag for any resource specified in the metadata.yaml of the charm. If all goes well, juju status should show the application status as active and the unit status as active (workload status) and idle (agent status), respectively. Sample session:

# Pack the charm:
~/example-k8s$ charmcraft pack
Created 'example-k8s_ubuntu-22.04-amd64.charm'.                                                                                                                                              
Charms packed:                                                                                                                                                                               
    example-k8s_ubuntu-22.04-amd64.charm 

# Deploy the charm from its local path:
~/example-k8s$ juju deploy ./example-k8s_ubuntu-22.04-amd64.charm --resource httpbin-image=kennethreitz/httpbin
Located local charm "example-k8s", revision 0
Deploying "example-k8s" from local charm "example-k8s", revision 0 on ubuntu@22.04/stable

# Check the charm's deployment status:
~/example-k8s$ juju status
Model        Controller  Cloud/Region        Version  SLA          Timestamp
welcome-k8s  microk8s    microk8s/localhost  3.1.6    unsupported  14:11:43+01:00

App          Version  Status  Scale  Charm        Channel  Rev  Address        Exposed  Message
example-k8s           active      1  example-k8s             0  10.152.183.43  no       

Unit            Workload  Agent  Address      Ports  Message
example-k8s/0*  active    idle   10.1.64.139         

See more: charmcraft pack, Juju | juju deploy, Juju | juju status

Update the deployment of a local charm by refreshing the charm

To update and redeploy the local charm: After repacking the charm, run juju refresh followed by the name of the deployed application (see juju status); the --path flag followed by the "-enclosed path to the charm; if applicable, the resource; and the -force-units flag, which will refresh all units immediately, even if in error. If all goes well, juju status should show all active and idle – but the charm’s revision number should increase by 1. Sample session:

# Repack the charm:
~/example-k8s$ charmcraft pack
Created 'example-k8s_ubuntu-22.04-amd64.charm'.                                              
Charms packed:                                                                               
    example-k8s_ubuntu-22.04-amd64.charm   

# Update the charm in Juju:
~/example-k8s$ juju refresh example-k8s --path="./example-k8s_ubuntu-22.04-amd64.charm" --resource httpbin-image=kennethreitz/httpbin --force-units
Added local charm "example-k8s", revision 1, to the model

# Check the charm's deployment status:
$ juju status
Model        Controller  Cloud/Region        Version  SLA          Timestamp
welcome-k8s  microk8s    microk8s/localhost  3.1.6    unsupported  14:16:37+01:00

App          Version  Status   Scale  Charm        Channel  Rev  Address        Exposed  Message
example-k8s           waiting      1  example-k8s             1  10.152.183.43  no       waiting for container

Unit            Workload  Agent  Address      Ports  Message
example-k8s/0*  active    idle   10.1.64.140         

See more: charmcraft pack, Juju | juju refresh, Juju | juju status

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