Scenario
Additional services shall be monitored graphically with the UCS Dashboard App.
Recommendation
The Dashboard is based on Prometheus and Grafana, therefore a service to be displayed needs to expose statistics as requested by Prometheus or you will need an additional Prometheus exporter per application.
If your service is emitting metrics, 3 steps are required to make them visible in the Dashboard:
Serve metrics via Apache
To gather the metrics with your Prometheus installation, they must be made available under [ADDRESS]/metrics-[SERVICE]/metrics/, for example https://dir-node.mydomain.intranet/metrics-ox/metrics/. This can be achieved with the following Apache Config:
LDAPTrustedMode TLS
<Location "/metrics-ox/metrics/">
AuthName "Prometheus Access"
AuthType Basic
require valid-user
<IfModule mod_authnz_ldap.c>
AuthBasicProvider ldap
AuthLDAPUrl "ldap://[LDAP-SERVER-NAME]:[LDAP-SERVER-PORT]/[LDAP-BASE]?uid?sub?(objectClass=*)"
AuthLDAPBindDN [LDAP-HOSTDN]
AuthLDAPBindPassword "exec:/bin/cat /etc/machine.secret"
</IfModule>
ProxyPass [METRICS-ENDPOINT] retry=0
ProxyPassReverse [METRICS-ENDPOINT]
</Location>
where for OX the [METRICS-ENDPOINT] would be http://127.0.0.1:8009/metrics and [LDAP-SERVER-NAME], [LDAP-SERVER-PORT], [LDAP-BASE] and [LDAP-HOSTDN] can be gathered via ucr get + ldap/base, ldap/server/name, ldap/server/port and /ldap/hostdn.
Apache needs to be restarted afterwards: service apache2 reload
Add service to Prometheus custom targets
On the prometheus instance, the file /var/lib/univention-appcenter/apps/prometheus/conf/custom-targets.json must be created and your service needs to be included like so:
[
{
"targets": [
"metrics-ox.dir-node.mydomain.intranet"
]
}
]
afterwards the Dashboard Database needs to be restarted: univention-app restart prometheus
As for now (August 2022) Prometheus relabels both custom and automatically configured targets like this:
relabel_configs:
- source_labels: [__address__]
separator: ;
regex: ([^\.]+)\..*
target_label: __metrics_path__
replacement: /$1/metrics/
action: replace
- source_labels: [__address__]
separator: ;
regex: '[^\.]+\.(.*)'
target_label: __address__
replacement: $1
action: replace
- source_labels: [__address__]
separator: ;
regex: (.*)
target_label: instance
replacement: $1
action: replace
The URL has to follow this format to be valid (e.g. in the example https://dir-node.mydomain.intranet/metrics-ox/metrics/ with scheme: https://A/B/C it has to be https://B.A → metrics-ox.dir-node.mydomain.intranet).
Make a new Dashboard
Since the Domain Dashboard and Server Dashboard cannot be edited, you need to create a new Dashboard in Grafana to be able to add a new graph. Inside this, your metrics can be queried with PromQL.
Further reading (optional)
Questions?
If you’re not sure whether the recommendations will fit into your scenario, please ask your Professional Services contact person, or create a new topic referencing this article.