Note: All commands are written for juju >= v3.1
If you’re using juju 2.9, check the juju 3.0 Release Notes.
Enable tracing
This guide contains the steps to enable tracing with Grafana Tempo for your PostgreSQL application.
To summarize:
- Deploy the Tempo charm in a COS K8s environment
- Integrate it with the COS charms
- Offer interfaces for cross-model integrations
- View PostgreSQL traces on Grafana
Warning: This is feature is in development. It is not recommended for production environments.
This feature is available for Charmed PostgreSQL revision 421+ only.
Prerequisites
Enabling tracing with Tempo requires that you:
- Have deployed a Charmed PostgreSQL application
- Have deployed a ‘cos-lite’ bundle from the
latest/edgetrack in a Kubernetes environment
Deploy Tempo
First, switch to the Kubernetes controller where the COS model is deployed:
juju switch <k8s_controller_name>:<cos_model_name>
Then, deploy the tempo-k8s charm:
juju deploy -n 1 tempo-k8s --channel latest/edge
Integrate with the COS charms
Integrate tempo-k8s with the COS charms as follows:
juju integrate tempo-k8s:grafana-dashboard grafana:grafana-dashboard
juju integrate tempo-k8s:grafana-source grafana:grafana-source
juju integrate tempo-k8s:ingress traefik:traefik-route
juju integrate tempo-k8s:metrics-endpoint prometheus:metrics-endpoint
juju integrate tempo-k8s:logging loki:logging
If you would like to instrument traces from the COS charms as well, create the following integrations:
juju integrate tempo-k8s:tracing alertmanager:tracing
juju integrate tempo-k8s:tracing catalogue:tracing
juju integrate tempo-k8s:tracing grafana:tracing
juju integrate tempo-k8s:tracing loki:tracing
juju integrate tempo-k8s:tracing prometheus:tracing
juju integrate tempo-k8s:tracing traefik:tracing
Offer interfaces
Next, offer interfaces for cross-model integrations from the model where Charmed PostgreSQL is deployed.
To offer the Tempo integration, run
juju offer tempo-k8s:tracing
Then, switch to the Charmed PostgreSQL model, find the offers, and integrate (relate) with them:
juju switch <machine_controller_name>:<postgresql_model_name>
juju find-offers <k8s_controller_name>:
Do not miss the “
:” in the command above.
Below is a sample output where k8s is the K8s controller name and cos is the model where cos-lite and tempo-k8s are deployed:
Store URL Access Interfaces
k8s admin/cos.tempo-k8s admin tracing:tracing
Next, consume this offer so that it is reachable from the current model:
juju consume k8s:admin/cos.tempo-k8s
Relate Charmed PostgreSQL with the above consumed interface:
juju integrate postgresql:tracing tempo-k8s:tracing
Wait until the model settles. The following is an example of the juju status --relations on the Charmed PostgreSQL model:
Model Controller Cloud/Region Version SLA Timestamp
database lxd localhost/localhost 3.4.3 unsupported 19:32:36Z
SAAS Status Store URL
tempo-k8s active k8s admin/cos.tempo-k8s
App Version Status Scale Charm Channel Rev Exposed Message
postgresql 14.11 active 1 postgresql 14/candidate 422 no
Unit Workload Agent Machine Public address Ports Message
postgresql/1* active idle 1 10.205.193.156 5432/tcp Primary
Machine State Address Inst id Base AZ Message
1 started 10.205.193.156 juju-ceca46-1 ubuntu@22.04 Running
Integration provider Requirer Interface Type Message
postgresql:database-peers postgresql:database-peers postgresql_peers peer
postgresql:restart postgresql:restart rolling_op peer
postgresql:upgrade postgresql:upgrade upgrade peer
tempo-k8s:tracing postgresql:tracing tracing regular
Note: All traces are exported to Tempo using HTTP. Support for sending traces via HTTPS is an upcoming feature.
View traces
After this is complete, the Tempo traces will be accessible from Grafana under the Explore section with tempo-k8s as the data source. You will be able to select postgresql as the Service Name under the Search tab to view traces belonging to Charmed PostgreSQL.
Below is a screenshot demonstrating a Charmed PostgreSQL trace:
Feel free to read through the Tempo documentation at your leisure to explore its deployment and its integrations.