docs: add task page for setting up metamonitoring (#6605) (#6648)

Signed-off-by: Paschalis Tsilias <[email protected]>
(cherry picked from commit 4b11fb1)

Co-authored-by: Paschalis Tsilias <[email protected]>

docs/sources/flow/tasks/metamonitoring.md

@@ -0,0 +1,156 @@
+---
+canonical: https://grafana.com/docs/agent/latest/flow/tasks/setup-metamonitoring/
+description: Learn how to set up meta-monitoring for Grafana Agent Flow
+title: Set up meta-monitoring
+weight: 200
+---
+
+# Set up meta-monitoring
+
+You can configure {{< param "PRODUCT_NAME" >}} to collect its own telemetry and forward it to the backend of your choosing.
+
+This topic describes how to collect and forward {{< param "PRODUCT_NAME" >}}'s metrics, logs and traces data.
+
+## Components and configuration blocks used in this topic
+
+* [prometheus.exporter.self][]
+* [prometheus.scrape][]
+* [logging][]
+* [tracing][]
+
+## Before you begin
+
+* Identify where to send {{< param "PRODUCT_NAME" >}}'s telemetry data.
+* Be familiar with the concept of [Components][] in {{< param "PRODUCT_NAME" >}}.
+
+## Meta-monitoring metrics
+
+{{< param "PRODUCT_NAME" >}} exposes its internal metrics using the Prometheus exposition format.
+
+In this task, you will use the [prometheus.exporter.self][] and [prometheus.scrape][] components to scrape {{< param "PRODUCT_NAME" >}}'s  internal metrics and forward it to compatible {{< param "PRODUCT_NAME" >}} components.
+
+1. Add the following `prometheus.exporter.self` component to your configuration. The component accepts no arguments.
+
+   ```river
+   prometheus.exporter.self "<SELF_LABEL>" {
+   }
+   ```
+
+1. Add the following `prometheus.scrape` component to your configuration file.
+   ```river
+   prometheus.scrape "<SCRAPE_LABEL>" {
+     targets    = prometheus.exporter.<SELF_LABEL>.default.targets
+     forward_to = [<METRICS_RECEIVER_LIST>]
+   }
+   ```
+
+   Replace the following:
+   - _`<SELF_LABEL>`_: The label for the component such as `default` or `metamonitoring`. The label must be unique across all `prometheus.exporter.self` components in the same configuration file.
+   - _`<SCRAPE_LABEL>`_: The label for the scrape component such as `default`. The label must be unique across all `prometheus.scrape` components in the same configuration file.
+   - _`<METRICS_RECEIVER_LIST>`_: A comma-delimited list of component receivers to forward metrics to.
+     For example, to send to an existing remote write component, use `prometheus.remote_write.WRITE_LABEL.receiver`.
+     Similarly, to send data to an existing relabeling component, use `prometheus.relabel.PROCESS_LABEL.receiver`.
+     To use data in the OTLP format, you can send data to an existing converter component, like `otelcol.receiver.prometheus.OTEL.receiver`.
+
+The following example demonstrates configuring a possible sequence of components.
+
+```river
+prometheus.exporter.self "default" {
+}
+
+prometheus.scrape "metamonitoring" {
+  targets    = prometheus.exporter.self.default.targets
+  forward_to = [prometheus.remote_write.default.receiver]
+}
+
+prometheus.remote_write "default" {
+  endpoint {
+    url = "http://mimir:9009/api/v1/push"
+  }
+}
+```
+
+## Meta-monitoring logs
+
+The [logging][] block defines the logging behavior of {{< param "PRODUCT_NAME" >}}.
+
+In this task, you will use the [logging][] block to forward {{< param "PRODUCT_NAME" >}}'s logs to a compatible component.
+The block is specified without a label and can only be provided once per configuration file.
+
+1. Add the following `logging` configuration block to the top level of your configuration file.
+
+   ```river
+   logging {
+     level    = "<LOG_LEVEL>"
+     format   = "<LOG_FORMAT>"
+     write_to = [<LOGS_RECEIVER_LIST>]
+   }
+   ```
+
+   Replace the following:
+   - _`<LOG_LEVEL>`_: The log level to use for {{< param "PRODUCT_NAME" >}}'s logs. If the attribute isn't set, it defaults to `info`.
+   - _`<LOG_FORMAT>`_: The log format to use for {{< param "PRODUCT_NAME" >}}'s logs. If the attribute isn't set, it defaults to `logfmt`.
+   - _`<LOGS_RECEIVER_LIST>`_: A comma-delimited list of component receivers to forward logs to.
+     For example, to send to an existing processing component, use `loki.process.PROCESS_LABEL.receiver`.
+     Similarly, to send data to an existing relabeling component, use `loki.relabel.PROCESS_LABEL.receiver`.
+     To use data in the OTLP format, you can send data to an existing converter component, like `otelcol.receiver.loki.OTEL.receiver`.
+
+The following example demonstrates configuring the logging block and sending to a compatible component.
+
+```river
+logging {
+  level    = "warn"  
+  format   = "json"
+  write_to = [loki.write.default.receiver]
+}
+
+loki.write "default" {
+  endpoint {
+    url = "http://loki:3100/loki/api/v1/push"
+  }
+}
+
+```
+
+## Meta-monitoring traces
+
+The [tracing][] block defines the tracing behavior of {{< param "PRODUCT_NAME" >}}.
+
+In this task you will use the [tracing][] block to forward {{< param "PRODUCT_NAME" >}} internal traces to a compatible component. The block is specified without a label and can only be provided once per configuration file.
+
+1. Add the following `tracing` configuration block to the top level of your configuration file.
+
+   ```river
+   tracing {
+     sampling_fraction = <SAMPLING_FRACTION>
+     write_to          = [<TRACES_RECEIVER_LIST>]
+   }
+   ```
+
+   Replace the following:
+   - _`<SAMPLING_FRACTION>`_: The fraction of traces to keep. If the attribute isn't set, it defaults to `0.1`.
+   - _`<TRACES_RECEIVER_LIST>`_: A comma-delimited list of component receivers to forward traces to.
+     For example, to send to an existing OpenTelemetry exporter component use `otelcol.exporter.otlp.EXPORT_LABEL.input`.
+
+The following example demonstrates configuring the tracing block and sending to a compatible component.
+
+```river
+tracing {
+  sampling_fraction = 0.1
+  write_to          = [otelcol.exporter.otlp.default.input]
+}
+
+otelcol.exporter.otlp "default" {
+    client {
+        endpoint = "tempo:4317"
+    }
+}
+```
+
+{{% docs/reference %}}
+[prometheus.exporter.self]: "/docs/agent/ -> /docs/agent/<AGENT_VERSION>/flow/reference/components/prometheus.exporter.self.md"
+[prometheus.scrape]: "/docs/agent/ -> /docs/agent/<AGENT_VERSION>/flow/reference/components/prometheus.scrape.md"
+[logging]: "/docs/agent/ -> /docs/agent/<AGENT_VERSION>/flow/reference/config-blocks/logging.md"
+[tracing]: "/docs/agent/ -> /docs/agent/<AGENT_VERSION>/flow/reference/config-blocks/tracing.md"
+[Components]: "/docs/agent/ -> /docs/agent/<AGENT_VERSION>/flow/concepts/components.md"
+{{% /docs/reference %}}