Kong Mesh facilitates consistent traffic metrics across all data plane proxies in your mesh.
You can define metrics configuration for a whole Mesh, and optionally tweak certain parts for individual data plane proxies.
For example, you might need to override the default metrics port if it’s already in use on the specified machine.
Kong Mesh provides full integration with Prometheus:
To collect metrics from Kong Mesh, you need to expose metrics from proxies and applications.
In the rest of this page we assume you have already configured your observability tools to work with Kong Mesh.
If you haven’t already read the observability docs.
There are three main sections of the configuration: sidecar, applications, backends.
The first two define how to scrape parts of the mesh (sidecar and underlying applications), the third one defines what to do with the data (in case of Prometheus instructs to scrape specific address, in case of OpenTelemetry defines where to push data).
In contrast to Traffic Metrics all configuration is dynamic and no restarts of the Data Plane Proxies are needed.
You can define configuration refresh interval by using KUMA_DATAPLANE_RUNTIME_DYNAMIC_CONFIGURATION_REFRESH_INTERVAL env var or kuma.dataplaneRuntime.dynamicConfiguration.refreshInterval Helm value.
This part of the configuration applies to the data plane proxy scraping.
In case you don’t want to retrieve all Envoy’s metrics, it’s possible to filter them.
Below are different methods of filtering.
The order of the operations is as follows:
Profiles are predefined sets of metrics with manual include and exclude functionality.
There are 3 sections:
appendProfiles - allows to combine multiple predefined profiles of metrics.
Right now you can only define one profile but this might change it the future
(for example there might be feature related profiles like “Fault injection profile” and “Circuit Breaker profile” so you can mix and match the ones that you need based on your features usage).
Today only 3 profiles are available: All, Basic and None.
All profile contains all metrics produced by Envoy.
Basic profile contains all metrics needed by Kong Mesh dashboards and golden 4 signals metrics.
None profile removes all metrics
exclude - after profiles are applied you can manually exclude metrics on top of profile filtering.
include - after exclude is applied you can manually include metrics.
Metrics exposed by the application need to be in Prometheus format for the Dataplane Proxy to be able to parse and expose them to either Prometheus or OpenTelemetry backend.
In addition to exposing metrics from the data plane proxies, you might want to expose metrics from applications running next to the proxies.
Kong Mesh allows scraping Prometheus metrics from the applications endpoint running in the same Pod or VM.
Later those metrics are aggregated and exposed at the same port/path as data plane proxy metrics.
It is possible to configure it at the Mesh level, for all the applications in the Mesh, or just for specific applications.
Here are reasons where you’d want to use this feature:
Application metrics are labelled with your mesh parameters (tags, mesh, data plane name…), this means that in mixed Universal and Kubernetes mode metrics are reported with the same types of labels.
Both application and sidecar metrics are scraped at the same time. This makes sure they are coherent (with 2 different scrapers they can end up scraping at different intervals and make metrics harder to correlate).
If you disable passthrough and your mesh uses mTLS and Prometheus is outside the mesh this is the only way to retrieve these metrics as the app is completely hidden behind the sidecar.
Example section of the configuration:
applications:-name:"backend"# application name used for logging and to scope OpenTelemetry metrics (optional)path:"/metrics/prometheus"# application metrics endpoint pathaddress:# optional custom address if the underlying application listens on a different address than the Data Plane Proxyport:8888# port on which application is listening
This tells Kong Mesh to expose an HTTP endpoint with Prometheus metrics on port 5670 and uri path /metrics.
The metrics endpoint is forwarded to the standard Envoy Prometheus metrics endpoint and supports the same query parameters.
You can pass the filter query parameter to limit the results to metrics whose names match a given regular expression.
By default, all available metrics are returned.
In addition to the MeshMetric configuration, kuma-sidecar requires a provided certificate and key for its operation.
When the certificate and key are available within the container, kuma-sidecar needs the paths to provided files as the following environment variables:
KUMA_DATAPLANE_RUNTIME_METRICS_CERT_PATH
KUMA_DATAPLANE_RUNTIME_METRICS_KEY_PATH
It’s possible to use a ContainerPatch to add variables to kuma-sidecar:
If you need to run multiple instances of Prometheus and want to target different set of Data Plane Proxies you can do this by using Client ID setting on both MeshMetric (clientId) and Prometheus configuration (client_id).
Support for clientId was added in Prometheus version 2.50.0.
Let’s assume we have two prometheus deployments main and secondary. We would like to use each of them to monitor different sets
of data plane proxies, with different tags.
We can start with configuring each Prometheus deployments to use Kuma SD.
Prometheus’s deployments will be differentiated by client_id parameter.
Main Prometheus config:
scrape_configs:-job_name:'kuma-dataplanes'# ...kuma_sd_configs:-server:http://kong-mesh-control-plane.kong-mesh-system:5676refresh_interval:60s# different from prometheus-secondaryclient_id:"prometheus-main"# Kuma will use this to pick proper data plane proxies
Secondary Prometheus config:
scrape_configs:-job_name:'kuma-dataplanes'# ...kuma_sd_configs:-server:http://kong-mesh-control-plane.kong-mesh-system:5676refresh_interval:20s# different from prometheus-mainclient_id:"prometheus-secondary"
Now we can configure first MeshMetric policy to pick data plane proxies with tag prometheus: main for main Prometheus discovery.
clientId in policy should be the same as client_id in Prometheus configuration.
This configuration tells Kong Mesh Dataplane Proxy to push metrics to OpenTelemetry collector.
Dataplane Proxy will scrape metrics from Envoy and other applications in a Pod/VM
and push them to configured OpenTelemetry collector, by default every 60 seconds (use refreshInterval to change it).
When you configure application scraping make sure to specify application.name to use OpenTelemetry scoping.