github.com/grafana/pyroscope@v1.18.0/docs/sources/configure-client/grafana-alloy/go_pull.md

---
title: Set up Go profiling in pull mode
menuTitle: Set up Go profiling in pull mode
description: Learn how to set up Go profiling in pull mode.
weight: 10
---

# Set up Go profiling in pull mode

In pull mode, the collector, Grafana Alloy, periodically retrieves profiles from Golang applications, specifically targeting the
`/debug/pprof/*` endpoints.

To set up Golang profiling in pull mode, you need to:

1. Expose pprof endpoints.
2. Install a collector, such as Grafana Alloy.
3. Prepare the collector's configuration file.
4. Start the collector.

## Expose pprof endpoints

Ensure your Golang application exposes pprof endpoints.

1. Get `godeltaprof` package

    ```bash
    go get github.com/grafana/pyroscope-go/godeltaprof@latest
    ```

2. Import `net/http/pprof` and `godeltaprof/http/pprof` packages at the start of your application.

    ```go
    import _ "net/http/pprof"
    import _ "github.com/grafana/pyroscope-go/godeltaprof/http/pprof"
    ```

## Install the collector

[//]: # (TODO(korniltsev) What should go here?)

You can use the sample Alloy collector configuration file to send data to Pyroscope.

To install Alloy, refer to [Grafana Alloy installation](https://grafana.com/docs/alloy/<ALLOY_VERSION>/get-started/install/).

### Prepare the collector configuration file

In the Alloy configuration file, you need to add at least two blocks: `pyroscope.write` and `pyroscope.scrape`.

1. Add `pyroscope.write` block.

    ```alloy
    pyroscope.write "write_job_name" {
            endpoint {
                    url = "http://localhost:4040"
            }
    }
    ```

1. Add `pyroscope.scrape` block.

    ```alloy
    pyroscope.scrape "scrape_job_name" {
            targets    = [{"__address__" = "localhost:4040", "service_name" = "example_service"}]
            forward_to = [pyroscope.write.write_job_name.receiver]

            profiling_config {
                    profile.process_cpu {
                            enabled = true
                    }

                    profile.godeltaprof_memory {
                            enabled = true
                    }

                    profile.memory { // disable memory, use godeltaprof_memory instead
                            enabled = false
                    }

                    profile.godeltaprof_mutex {
                            enabled = true
                    }

                    profile.mutex { // disable mutex, use godeltaprof_mutex instead
                            enabled = false
                    }

                    profile.godeltaprof_block {
                            enabled = true
                    }

                    profile.block { // disable block, use godeltaprof_block instead
                            enabled = false
                    }

                    profile.goroutine {
                            enabled = true
                    }
            }
    }

    ```

1. Save the changes to the file.

### Start the collector

1. Start a local Pyroscope instance for testing purposes:
    ```bash
    docker run -p 4040:4040 grafana/pyroscope
    ```

1. To start Alloy v1.2 and later: Replace `configuration.alloy` with your configuration filename: <br> `alloy run configuration.alloy`

1. Open a browser to `http://localhost:4040`. The page should list profiles.

## Examples

### Send data to Grafana Cloud

Your Grafana Cloud URL, username, and password can be found on the "Details Page" for Pyroscope from your stack on
grafana.com.
On this same page, create a token and use it as the Basic authentication password.

```alloy
pyroscope.write "write_job_name" {
        endpoint {
                url = "<Grafana Cloud URL>"

                basic_auth {
                        username = "<Grafana Cloud User>"
                        password = "<Grafana Cloud Password>"
                }
        }

}
```

### Discover Kubernetes targets

1. Select all pods

  ```alloy
  discovery.kubernetes "all_pods" {
          role = "pod"
  }
  ```

1. Drop not running pods, create `namespace`, `pod`, `node` and `container` labels.
  Compose `service_name` label based on `namespace` and `container` labels.
  Select only services matching regex pattern `(ns1/.*)|(ns2/container-.*0)`.
    ```alloy

    discovery.relabel "specific_pods" {
            targets = discovery.kubernetes.all_pods.targets

            rule {
                    action        = "drop"
                    regex         = "Succeeded|Failed|Completed"
                    source_labels = ["__meta_kubernetes_pod_phase"]
            }

            rule {
                    action        = "replace"
                    source_labels = ["__meta_kubernetes_namespace"]
                    target_label  = "namespace"
            }

            rule {
                    action        = "replace"
                    source_labels = ["__meta_kubernetes_pod_name"]
                    target_label  = "pod"
            }

            rule {
                    action        = "replace"
                    source_labels = ["__meta_kubernetes_node_name"]
                    target_label  = "node"
            }

            rule {
                    action        = "replace"
                    source_labels = ["__meta_kubernetes_pod_container_name"]
                    target_label  = "container"
            }

            rule {
                    action        = "replace"
                    regex         = "(.*)@(.*)"
                    replacement   = "${1}/${2}"
                    separator     = "@"
                    source_labels = ["__meta_kubernetes_namespace", "__meta_kubernetes_pod_container_name"]
                    target_label  = "service_name"
            }

            rule {
                    action        = "keep"
                    regex         = "(ns1/.*)|(ns2/container-.*0)"
                    source_labels = ["service_name"]
            }
    }
    ```

1. Use `discovery.relabel.specific_pods.output` as a target for `pyroscope.scrape` block.

    ```alloy
        pyroscope.scrape "scrape_job_name" {
                targets    = discovery.relabel.specific_pods.output
                ...
        }
    ```

### Exposing pprof endpoints

If you don't use `http.DefaultServeMux`, you can register `/debug/pprof/*` handlers to your own `http.ServeMux`:

```go
var mux *http.ServeMux
mux.Handle("/debug/pprof/", http.DefaultServeMux)
```

Or, if you use gorilla/mux:

```go
var router *mux.Router
router.PathPrefix("/debug/pprof").Handler(http.DefaultServeMux)
```

## References

- [Grafana Alloy](https://grafana.com/docs/alloy/<ALLOY_VERSION>/)
- [pyroscope.scrape](https://grafana.com/docs/alloy/<ALLOY_VERSION>/reference/components/pyroscope/pyroscope.scrape/)
- [pyroscope.write](https://grafana.com/docs/alloy/<ALLOY_VERSION>/reference/components/pyroscope/pyroscope.write/)
- [discovery.kubernetes](https://grafana.com/docs/alloy/<ALLOY_VERSION>/reference/components/discovery/discovery.kubernetes/)
- [discovery.docker](https://grafana.com/docs/alloy/<ALLOY_VERSION>/reference/components/discovery/discovery.docker/)
- [discovery.relabel](https://grafana.com/docs/alloy/<ALLOY_VERSION>/reference/components/discovery/discovery.relabel/)