Add metrics documentation (#9848)

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@ -24,10 +24,9 @@ metrics destination and service protocol you may want to enable [configuration
entries](/docs/agent/options#config_entries) and [centralized service
configuration](/docs/agent/options#enable_central_service_config).
If you
are using Kubernetes, the Helm chart can simplify much of the necessary
configuration, which you can learn about in the [observability
tutorial](https://learn.hashicorp.com/tutorials/consul/kubernetes-layer7-observability).
### Kubernetes
If you are using Kubernetes, the Helm chart can simplify much of the configuration needed to enable observability. See
our [Kubernetes observability docs](/docs/k8s/connect/observability/metrics) for more information.
### Metrics Destination

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@ -33,6 +33,10 @@ Consul has built-in support for overlaying metrics from a
be supported using a new and experimental JavaScript API. See [Custom Metrics
Providers](#custom-metrics-providers).
## Kubernetes
If running Consul in Kubernetes, the Helm chart can automatically configure Consul's UI to display topology
visualizations. See our [Kubernetes observability docs](/docs/k8s/connect/observability/metrics) for more information.
## Configuring the UI To Display Metrics
To configure Consul's UI to fetch metrics there are two required configuration settings.
@ -70,6 +74,8 @@ ui_config {
}
```
Similarly, to configure the UI on Kubernetes, use this [reference](/docs/k8s/connect/observability/metrics).
## Configuring Dashboard URLs
Since Consul's visualization is intended as an overview of your mesh and not a

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@ -275,7 +275,7 @@ Annotations can be used to configure the injection behavior.
consul.hashicorp.com/service-meta-bar: baz
```
- `consul.hashicorp.com/sidecar-proxy-` - override default resource settings for
- `consul.hashicorp.com/sidecar-proxy-` - Override default resource settings for
the sidecar proxy container.
The defaults are set in Helm config via the [`connectInject.sidecarProxy.resources`](/docs/k8s/helm#v-connectinject-sidecarproxy-resources) key.
@ -284,6 +284,14 @@ Annotations can be used to configure the injection behavior.
- `consul.hashicorp.com/sidecar-proxy-memory-limit` - Override the default memory limit.
- `consul.hashicorp.com/sidecar-proxy-memory-request` - Override the default memory request.
- `consul.hashicorp.com/enable-metrics` - Override the default Helm value [`connectInject.metrics.defaultEnabled`](/docs/k8s/helm#v-connectinject-metrics-defaultenabled).
- `consul.hashicorp.com/enable-metrics-merging` - Override the default Helm value [`connectInject.metrics.defaultEnableMerging`](/docs/k8s/helm#v-connectinject-metrics-defaultenablemerging).
- `consul.hashicorp.com/merged-metrics-port` - Override the default Helm value [`connectInject.metrics.defaultMergedMetricsPort`](/docs/k8s/helm#v-connectinject-metrics-defaultmergedmetricsport).
- `consul.hashicorp.com/prometheus-scrape-port` - Override the default Helm value [`connectInject.metrics.defaultPrometheusScrapePort`](/docs/k8s/helm#v-connectinject-metrics-defaultprometheusscrapeport).
- `consul.hashicorp.com/prometheus-scrape-path` - Override the default Helm value [`connectInject.metrics.defaultPrometheusScrapePath`](/docs/k8s/helm#v-connectinject-metrics-defaultprometheusscrapepath).
- `consul.hashicorp.com/service-metrics-port` - Set the port where the Connect service exposes metrics.
- `consul.hashicorp.com/service-metrics-path` - Set the path where the Connect service exposes metrics.
### Deployments, StatefulSets, etc.
The annotations for configuring Connect must be on the pod specification.

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@ -0,0 +1,146 @@
---
layout: docs
page_title: Metrics
sidebar_title: Metrics
description: Metrics for Consul on Kubernetes
---
# Metrics
Consul on Kubernetes integrates with Prometheus and Grafana to provide metrics for Consul Service Mesh. The metrics
available are:
* Connect Service metrics
* Sidecar proxy metrics
* Consul agent metrics
* Ingress, Terminating and Mesh Gateway metrics
Specific sidecar proxy metrics can also be seen in the Consul UI Topology Visualization view. This section documents how to enable each of these.
-> **Note:** Metrics will be supported in Consul-helm >= `0.31.0` and consul-k8s >= `0.25.0`. However, enabling the [metrics merging feature](#connect-service-and-sidecar-metrics-with-metrics-merging) with Helm value (`defaultEnableMerging`) or
annotation (`consul.hashicorp.com/enable-metrics-merging`) can only be used with Consul `1.10.0-alpha1` and above. The
other metrics configuration can still be used before Consul `1.10.0-alpha1`.
## Connect Service and Sidecar Metrics with Metrics Merging
Prometheus annotations are used to instruct Prometheus to scrape metrics from Pods. Prometheus annotations only support
scraping from one endpoint on a Pod, so Consul on Kubernetes supports metrics merging whereby service metrics and
sidecar proxy metrics are merged into one endpoint. If there are no service metrics, it also supports just scraping the
sidecar proxy metrics.
The diagram below illustrates how the metrics integration works when merging is enabled:
[![Metrics Merging Architecture](/img/metrics-arch.png)](/img/metrics-arch.png)
Connect service metrics can be configured with the Helm values nested under [`connectInject.metrics`](/docs/k8s/helm#v-connectinject-metrics).
Metrics and metrics merging can be enabled by default for all connect-injected Pods with the following Helm values:
```yaml
connectInject:
metrics:
defaultEnabled: true # by default, this inherits from the value global.metrics.enabled
defaultEnableMerging: true
```
They can also be overridden on a per-Pod basis using the annotations `consul.hashicorp.com/enable-metrics` and
`consul.hashicorp.com/enable-metrics-merging`.
~> In most cases, the default settings will be sufficient. If you are encountering issues with colliding ports or service
metrics not being merged, you may need to change the defaults.
The Prometheus annotations configure the endpoint to scrape the metrics from. As shown in the diagram, the annotations point to a listener on `0.0.0.0:20200` on the Envoy sidecar. This listener and the corresponding Prometheus annotations can be configured with the following Helm values (or overridden on a per-Pod basis with Consul annotations `consul.hashicorp.com/prometheus-scrape-port` and `consul.hashicorp.com/prometheus-scrape-path`):
```yaml
connectInject:
metrics:
defaultPrometheusScrapePort: 20200
defaultPrometheusScrapePath: "/metrics"
```
Those Helm values will result in the following Prometheus annotations being automatically added to the Pod for scraping:
```yaml
metadata:
annotations:
prometheus.io/scrape: "true"
prometheus.io/path: "/metrics"
prometheus.io/port: "20200"
```
When metrics alone are enabled, the listener in the diagram on `0.0.0.0:20200` would point directly at the sidecar
metrics endpoint, rather than the merged metrics endpoint. The Prometheus scraping annotations would stay the same.
When metrics and metrics merging are *both* enabled, metrics are combined from the service and the sidecar proxy, and
exposed via a local server on the Consul sidecar for scraping. This endpoint is called the merged metrics endpoint and
defaults to `127.0.0.1:20100/stats/prometheus`. The listener will target the merged metrics endpoint in the above case.
It can be configured with the following Helm values (or overridden on a per-Pod basis with
`consul.hashicorp.com/merged-metrics-port`):
```yaml
connectInject:
metrics:
defaultMergedMetricsPort: 20100
```
The endpoint to scrape service metrics from can be configured only on a per-Pod basis via the Pod annotations `consul.hashicorp.com/service-metrics-port` and `consul.hashicorp.com/service-metrics-path`. If these are not configured, the service metrics port will default to the port used to register the service with Consul (`consul.hashicorp.com/connect-service-port`), which in turn defaults to the first port on the first container of the Pod. The service metrics path will default to `/metrics`.
## Consul Agent Metrics
Metrics from the Consul server and client Pods can be scraped via Prometheus by setting the field `global.metrics.enableAgentMetrics` to `true`. Additionally, one can configure the metrics retention time on the agents by configuring
the field `global.metrics.agentMetricsRetentionTime` which expects a duration and defaults to `"1m"`. This value must be greater than `"0m"` for the Consul servers and clients to emit metrics at all. As the Prometheus deployment currently does not support scraping TLS endpoints, agent metrics are currently *unsupported* when TLS is enabled.
```yaml
global:
metrics:
enabled: true
enableAgentMetrics: true
agentMetricsRetentionTime: "1m"
```
## Gateway Metrics
Metrics from the Consul gateways, namely the Ingress Gateways, Terminating Gateways and the Mesh Gateways can be scraped
via Prometheus by setting the field `global.metrics.enableGatewayMetrics` to `true`. The gateways emit standard Envoy proxy
metrics. To ensure that the metrics are not exposed to the public internet (as Mesh and Ingress gateways can have public
IPs), their metrics endpoints are exposed on the Pod IP of the respective gateway instance, rather than on all
interfaces on `0.0.0.0`.
```yaml
global:
metrics:
enabled: true
enableGatewayMetrics: true
```
## Metrics in the UI Topology Visualization
Consuls built-in UI has a topology visualization for services part of the Consul Service Mesh. The topology visualization has the ability to fetch basic metrics from a metrics provider for each service and display those metrics as part of the [topology visualization](/docs/connect/observability/ui-visualization).
The diagram below illustrates how the UI displays service metrics for a sample application:
[![UI Topology View](/img/ui-topology.png)](/img/ui-topology.png)
The topology view is configured under `ui.metrics`. This will enable the Consul UI to query the provider specified by
`ui.metrics.provider` at the URL of the Prometheus server `ui.metrics.baseURL` to display sidecar proxy metrics for the
service. The UI will display some specific sidecar proxy Prometheus metrics when `ui.metrics.enabled` is `true` and
`ui.enabled` is true. The value of `ui.metrics.enabled` defaults to `"-"` which means it will inherit from the value of
`global.metrics.enabled.`
```yaml
ui:
enabled: true
metrics:
enabled: true # by default, this inherits from the value global.metrics.enabled
provider: "prometheus"
baseURL: http://prometheus-server
```
## Deploying Prometheus and Grafana (_for demo and non-production use-cases only_)
The Helm chart contains demo manifests for Prometheus and Grafana. They can be installed with Helm via `prometheus.enabled` and `grafana.enabled`. These manifests are based on the community manifests for Prometheus and Grafana.
These are designed to allow quick bootstrapping for trial and demo use cases and not for production use-cases.
Prometheus and Grafana will be installed in the same namespace that Consul will be installed in and will be installed
and uninstalled along with the Consul installation.
```yaml
prometheus:
enabled: true
grafana:
enabled: true
```

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@ -216,6 +216,24 @@ and consider if they're appropriate for your deployment.
`<global.name>-federation` (if setting `global.name`), otherwise
`<helm-release-name>-consul-federation`. Requires consul-k8s 0.15.0+.
- `metrics` ((#v-global-metrics)) - Configures metrics for Consul service mesh
- `enabled` ((#v-global-metrics-enabled)) (`boolean: false`) - Configures the Helm charts components
to expose Prometheus metrics for the Consul service mesh. By default
this includes gateway metrics and sidecar metrics.
- `enableAgentMetrics` ((#v-global-metrics-enableagentmetrics)) (`boolean: false`) - Configures consul agent metrics. Only applicable if
`global.metrics.enabled` is true.
- `agentMetricsRetentionTime` ((#v-global-metrics-agentmetricsretentiontime)) (`string: 1m`) - Configures the retention time for metrics in Consul clients and
servers. This must be greater than 0 for Consul clients and servers
to expose any metrics at all.
Only applicable if `global.metrics.enabled` is true.
- `enableGatewayMetrics` ((#v-global-metrics-enablegatewaymetrics)) (`boolean: true`) - If true, mesh, terminating, and ingress gateways will expose their
Envoy metrics on port `20200` at the `/metrics` path and all gateway pods
will have Prometheus scrape annotations. Only applicable if `global.metrics.enabled` is true.
- `consulSidecarContainer` ((#v-global-consulsidecarcontainer)) (`map`) - The consul sidecar ensures the Consul services
are always registered with their local Consul clients and is used by the
ingress/terminating/mesh gateways as well as with every Connect-injected service.
@ -278,7 +296,7 @@ and consider if they're appropriate for your deployment.
enable `server.exposeGossipAndRPCPorts` and `client.exposeGossipPorts`,
that will configure the LAN gossip ports on the servers and clients to be
hostPorts, so if you are running clients and servers on the same node the
ports will conflict if they are both 8301. When you enable
ports will conflict if they are both 8301. When you enable
`server.exposeGossipAndRPCPorts` and `client.exposeGossipPorts`, you must
change this from the default to an unused port on the host, e.g. 9301. By
default the LAN gossip port is 8301 and configured as a containerPort on
@ -806,6 +824,18 @@ and consider if they're appropriate for your deployment.
'annotation-key': annotation-value
```
- `metrics` ((#v-ui-metrics)) - Configurations for displaying metrics in the UI.
- `enabled` ((#v-ui-metrics-enabled)) (`boolean: global.metrics.enabled`) - Enable displaying metrics in the UI. The default value of "-"
will inherit from `global.metrics.enabled` value.
- `provider` ((#v-ui-metrics-provider)) (`string: prometheus`) - Provider for metrics. See
https://www.consul.io/docs/agent/options#ui_config_metrics_provider
This value is only used if `ui.enabled` is set to true.
- `baseURL` ((#v-ui-metrics-baseurl)) (`string: http://prometheus-server`) - baseURL is the URL of the prometheus server, usually the service URL.
This value is only used if `ui.enabled` is set to true.
- `syncCatalog` ((#v-synccatalog)) - Configure the catalog sync process to sync K8S with Consul
services. This can run bidirectional (default) or unidirectionally (Consul
to K8S or K8S to Consul only).
@ -982,6 +1012,42 @@ and consider if they're appropriate for your deployment.
- `reconcilePeriod` ((#v-connectinject-healthchecks-reconcileperiod)) (`string: 1m`) - If `healthChecks.enabled` is set to `true`, `reconcilePeriod` defines how often a full state
reconcile is done after the initial reconcile at startup is completed.
- `metrics` ((#v-connectinject-metrics)) - Configures metrics for Consul Connect services. All values are overridable
via annotations on a per-pod basis.
- `defaultEnabled` ((#v-connectinject-metrics-defaultenabled)) (`string: -`) - If true, the connect-injector will automatically
add prometheus annotations to connect-injected pods. It will also
add a listener on the Envoy sidecar to expose metrics. The exposed
metrics will depend on whether metrics merging is enabled:
- If metrics merging is enabled:
the Consul sidecar will run a merged metrics server
combining Envoy sidecar and Connect service metrics,
i.e. if your service exposes its own Prometheus metrics.
- If metrics merging is disabled:
the listener will just expose Envoy sidecar metrics.
This will inherit from `global.metrics.enabled`.
- `defaultEnableMerging` ((#v-connectinject-metrics-defaultenablemerging)) (`boolean: false`) - Configures the Consul sidecar to run a merged metrics server
to combine and serve both Envoy and Connect service metrics.
- `defaultMergedMetricsPort` ((#v-connectinject-metrics-defaultmergedmetricsport)) (`integer: 20100`) - Configures the port at which the Consul sidecar will listen on to return
combined metrics. This port only needs to be changed if it conflicts with
the application's ports.
- `defaultPrometheusScrapePort` ((#v-connectinject-metrics-defaultprometheusscrapeport)) (`integer: 20200`) - Configures the port Prometheus will scrape metrics from, by configuring
the Pod annotation `prometheus.io/port` and the corresponding listener in
the Envoy sidecar.
NOTE: This is *not* the port that your application exposes metrics on.
That can be configured with the
`consul.hashicorp.com/service-metrics-port` annotation.
- `defaultPrometheusScrapePath` ((#v-connectinject-metrics-defaultprometheusscrapepath)) (`string: /metrics`) - Configures the path Prometheus will scrape metrics from, by configuring the pod
annotation `prometheus.io/path` and the corresponding handler in the Envoy
sidecar.
NOTE: This is *not* the path that your application exposes metrics on.
That can be configured with the
`consul.hashicorp.com/service-metrics-path` annotation.
- `cleanupController` ((#v-connectinject-cleanupcontroller)) - Cleanup controller cleans up Consul service instances that remain registered
despite their pods no longer running. This could happen if the pod's `preStop`
hook failed to execute for some reason.
@ -1462,6 +1528,16 @@ and consider if they're appropriate for your deployment.
- `name` ((#v-terminatinggateways-gateways-name)) (`string: terminating-gateway`)
- `prometheus` ((#v-prometheus)) - Configures a demo Prometheus installation.
- `enabled` ((#v-prometheus-enabled)) (`boolean: false`) - When true, the Helm chart will install a demo Prometheus server instance
alongside Consul.
- `grafana` ((#v-grafana)) - Configures a demo Grafana installation.
- `enabled` ((#v-grafana-enabled)) (`boolean: false`) - When true, the Helm chart will install a demo Grafana instance
alongside Consul.
- `tests` ((#v-tests)) - Control whether a test Pod manifest is generated when running helm template.
When using helm install, the test Pod is not submitted to the cluster so this
is only useful when running helm template.

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@ -178,6 +178,7 @@ export default [
'connect-ca-provider',
'ambassador',
'health',
{ category: 'observability', content: ['metrics'], name: "Observability" },
],
},
'service-sync',

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