Kong Mesh facilitates consistent traffic metrics across all data plane proxies in your mesh.
You can add metrics to a mesh configuration, or to an individual data plane proxy configuration. For example, you might need metrics for individual data plane proxies to override the default metrics port if it’s already in use on the specified machine.
Kong Mesh provides full integration with Prometheus:
- Each proxy can expose its metrics in Prometheus format.
- Because metrics are part of the mesh configuration, Kong Mesh exposes an API called the monitoring assignment service (MADS) which exposes every proxy in the mesh.
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.
Expose metrics from data plane proxies
To expose metrics from every proxy in the mesh, configure the
This tells Kong Mesh to configure every proxy in the
default mesh to expose an HTTP endpoint with Prometheus metrics on port
5670 and URI path
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.
Secure metrics with TLS
Kong Mesh allows configuring metrics endpoint with TLS. You can use it when the
Prometheus deployment is outside of the mesh and requires secure communication.
Expose metrics from applications
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
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 but Prometheus is outside the mesh
this is the only way to retrieve these metrics as the app is completely hidden behind the sidecar.
Any configuration change requires redeployment of the data plane.
This configuration will cause every application in the mesh to be scrapped for metrics by the data plane proxy. If you need to expose metrics only for the specific application it is possible through
annotation for Kubernetes or
Dataplane resource for Universal deployment.
Override Prometheus settings per data plane proxy
Filter Envoy metrics
In case you don’t want to retrieve all Envoy’s metrics, it’s possible to filter them. Configuration is dynamic and doesn’t require a restart of a sidecar. You are able to specify
regex which causes that metric’s endpoint returns only matching metrics. Also, you can set flag
usedOnly that returns only metrics updated by Envoy.
Secure data plane proxy metrics
Kong Mesh lets you expose proxy metrics in a secure way by leveraging mTLS. Prometheus needs to be a part of the mesh for this feature to work, which is the default deployment mode on Kubernetes when using
kumactl install observability.