gabrielcocenza / charm-prometheus-juju-exporter

Charm that deploys exporter, publishing statistics about juju-deployed machines

prometheus-juju-exporter

This charm collects statistics about machines deployed by juju controller and exports them as a Prometheus metrics.

Core collecting and exporting functionality is implemented in the prometheus-juju-exporter snap. This snap can be either provided manually during the deployment as a resource or this charm will attempt to download it from Snap Store.

Collected Data

Main focus of this exporter is to provide insight about how many machines are deployed by the Juju controller and what's their state. The installed exporter snap will try to connect to the controller and crawl through every model, collecting information about deployed machines.

Resulting metrics contain numeric representation 1 (UP) or 0 (DOWN) for each machine deployed by the controller. In addition, each machine (metric) has labels that help to uniquely identify it:

• hostname - hostname of the machine as reported by Juju
• juju_model - name of the model in which the machine is deployed
• cloud_name - name of the cloud that hosts the model
• customer - name of the customer/organization that owns the controller
• type - (Experimental) Distinguishes various host types
  • metal - Physical machine
  • kvm - Virtual Machine
  • lxd - LXD container

Example data:

# HELP juju_machine_state Running status of juju machines
# TYPE juju_machine_state gauge
juju_machine_state{customer="DOC",hostname="juju-882749-controller-0",job="prometheus-juju-exporter",cloud_name="openstack-cloud-serverstack",juju_model="controller",type="kvm"} 1.0
juju_machine_state{customer="DOC",hostname="juju-882749-controller-3",job="prometheus-juju-exporter",cloud_name="openstack-cloud-serverstack",juju_model="controller",type="kvm"} 1.0
juju_machine_state{customer="DOC",hostname="juju-ad368d-test-0",job="prometheus-juju-exporter",cloud_name="openstack-cloud-serverstack",juju_model="test",type="kvm"} 1.0
juju_machine_state{customer="DOC",hostname="juju-ad368d-test-1",job="prometheus-juju-exporter",cloud_name="openstack-cloud-serverstack",juju_model="test",type="kvm"} 1.0

Charm configuration

The charm requires certain configuration options to be set for it to function properly. Until all required options are configured, the units will remain in Blocked state. User can examine unit logs to see which required options are missing from configuration.

In particular, this charm needs juju credentials and endpoint of a Juju controller. This might seem unnecessary as the charm is already being deployed in the juju environment but the fact is that the charm unit itself has very little information about the cloud/model/controller that it's deployed in. On its own, it's not capable of performing any introspection. That's why we need the credentials, to connect to the controller as a regular juju client. You can create separate Juju account for this purpose or in the development environments, you can reuse your own user/password (usually found in ~/.local/share/juju/accounts.yaml).

Note: Normally, superuser privilege is expected for such a user for full access to the controller. However, in case it is not possible, the minimum privilege requirements are:

1. login access to the controller instance and admin access to the model hosting the controller
2. admin access to any model that's expected to be monitored by this exporter

Required options:

• customer
• cloud-name
• controller-url
• juju-user
• juju-password

(Use juju config prometheus-juju-exporter to get more information about each option.)

Manual Deployment

This is currently (#TODO) the only way to deploy this charm as neither the charm nor the snap for the exporter are published in their respective stores.

Step 0 - Clone and build the snap

Clone prometheus-juju-exporter snap and build the snap using snapcraft

git clone https://github.com/canonical/prometheus-juju-exporter.git
cd prometheus-juju-exporter/
make build

Step 1 - Clone and build the charm

Clone this repository (if you haven't already) and run make build.

git clone https://github.com/canonical/charm-prometheus-juju-exporter.git
cd charm-prometheus-juju-exporter/
git submodule init
git submodule update
make build

Step 2 - Deploy charm with snap as a resource

This is a subordinate charm, so we'll need additional principal charm for its deployment. We can use the ubuntu charm for this. We'll also deploy Prometheus so we can work with collected data.

juju deploy ./prometheus-juju-exporter.charm --resource exporter-snap=<PATH_TO_EXPORTER_SNAP>
juju deploy ubuntu
juju deploy prometheus2
juju relate prometheus-juju-exporter ubuntu
juju relate prometheus2:scrape prometheus-juju-exporter
# (Optional) You can throw in Grafana into the mix
juju deploy grafana
juju relate grafana:grafana-source prometheus2

Step 3 - Configuration

At this point the unit of prometheus-juju-exporter should be in Blocked state as it's missing crucial configuration options. Following is a sample configuration:

juju config prometheus-juju-exporter \
  customer="Test Org" \
  cloud-name="Test Cloud" \
  controller-url="10.75.224.63:17070" \
  juju-user=admin \
  juju-password="86333204f5b22495550ab2c64a05607a"

Step 4 - Verify deployment

To make sure that everything works, check status of the unit and try to fetch exported metrics.

$ juju status
Model    Controller  Cloud/Region         Version  SLA          Timestamp
billing  local-lxd   localhost/localhost  2.9.33   unsupported  16:44:57+01:00

App                       Version  Status  Scale  Charm                     Channel  Rev  Exposed  Message
grafana                            active      1  grafana                   stable    59  no       Ready
prometheus-juju-exporter           active      1  prometheus-juju-exporter             0  no       Unit is ready
prometheus2                        active      1  prometheus2               stable    33  no       Ready
ubuntu                    20.04    active      1  ubuntu                    stable    21  no

Unit                           Workload  Agent  Machine  Public address  Ports               Message
grafana/0*                     active    idle   2        10.75.224.197   3000/tcp            Ready
prometheus2/0*                 active    idle   1        10.75.224.118   9090/tcp,12321/tcp  Ready
ubuntu/0*                      active    idle   0        10.75.224.13
  prometheus-juju-exporter/0*  active    idle            10.75.224.13    5000/tcp            Unit is ready

$ curl http://10.75.224.13:5000/metrics
# HELP juju_machine_state Running status of juju machines
# TYPE juju_machine_state gauge
juju_machine_state{cloud_name="Test Cloud",customer="Test Org",hostname="juju-be56b1-0",job="prometheus-juju-exporter",juju_model="billing",type="metal"} 1.0
juju_machine_state{cloud_name="Test Cloud",customer="Test Org",hostname="juju-be56b1-1",job="prometheus-juju-exporter",juju_model="billing",type="metal"} 1.0
juju_machine_state{cloud_name="Test Cloud",customer="Test Org",hostname="juju-be56b1-2",job="prometheus-juju-exporter",juju_model="billing",type="metal"} 1.0
juju_machine_state{cloud_name="Test Cloud",customer="Test Org",hostname="juju-d53a52-0",job="prometheus-juju-exporter",juju_model="controller",type="metal"} 1.0

Other resources

• Read more

• Contributing

• See the Juju SDK documentation for more information about developing and improving charms.