Merge pull request kubernetes-sigs#4160 from TAM360/feat/pprof-docs

📖 Add new documentation explaining the usage of Pprof

docs/book/src/SUMMARY.md

@@ -95,6 +95,7 @@
   - [completion](./reference/completion.md)
   - [Artifacts](./reference/artifacts.md)
   - [Platform Support](./reference/platform.md)
+  - [Monitoring with Pprof](./reference/pprof-tutorial.md)
 
   - [Manager and CRDs Scope](./reference/scopes.md)
 

docs/book/src/reference/pprof-tutorial.md

@@ -0,0 +1,62 @@
+# Monitoring Performance with Pprof
+
+[Pprof][github], a Go profiling tool, helps identify performance bottlenecks in areas like CPU and memory usage. It's integrated with the controller-runtime library's HTTP server, enabling profiling via HTTP endpoints. You can visualize the data using go tool pprof. Since [Pprof][github] is built into controller-runtime, no separate installation is needed. [Manager options][manager-options-doc] make it easy to enable pprof and gather runtime metrics to optimize controller performance.
+
+<aside class="note warning">
+<h1>Not Recommended for Production</h1>
+
+While [Pprof][github] is an excellent tool for profiling and debugging, it is not recommended to leave it enabled in production environments. The primary reasons are:
+
+1. **Security Risk**: The profiling endpoints expose detailed information about your application's performance and resource usage, which could be exploited if accessed by unauthorized users.
+2. **Overhead**: Running profiling can introduce performance overhead, mainly CPU usage, especially under heavy load, potentially impacting production workloads.
+
+</aside>
+
+## How to use Pprof?
+
+1. **Enabling Pprof**
+
+    In your `cmd/main.go` file, add the field:
+
+    ```golang
+    mgr, err := ctrl.NewManager(ctrl.GetConfigOrDie(), ctrl.Options{
+      ...
+      // PprofBindAddress is the TCP address that the controller should bind to
+      // for serving pprof. Specify the manager address and the port that should be bind.
+      PprofBindAddress:       ":8082",
+      ...
+    })
+    ```
+
+2. **Test It Out**
+
+    After enabling [Pprof][github], you need to build and deploy your controller to test it out. Follow the steps in the [Quick Start guide][quick-start-run-it] to run your project locally or on a cluster.
+
+    Then, you can apply your CRs/samples in order to monitor the performance of its controllers.
+
+3. **Exporting the data**
+
+    Using `curl`, export the profiling statistics to a file like this:
+
+    ```bash
+    # Note that we are using the bind host and port configured via the
+    # Manager Options in the cmd/main.go
+    curl -s "http://127.0.0.1:8082/debug/pprof/profile" > ./cpu-profile.out
+    ```
+
+4. **Visualizing the results on Browser**
+
+    ```bash
+    # Go tool will open a session on port 8080.
+    # You can change this as per your own need.
+    go tool pprof -http=:8080 ./cpu-profile.out
+    ```
+
+    Visualizaion results will vary depending on the deployed workload, and the Controller's behavior.
+    However, you'll see the result on your browser similar to this one:
+
+    ![pprof-result-visualization](./images/pprof-result-visualization.png)
+
+[manager-options-doc]: https://pkg.go.dev/sigs.k8s.io/controller-runtime/pkg/manager
+[quick-start-run-it]: ../quick-start.md#test-it-out
+[github]: https://github.com/google/pprof

docs/book/src/reference/reference.md

@@ -27,6 +27,7 @@
       - [Object/DeepCopy](markers/object.md)
       - [RBAC](markers/rbac.md)
 
+  - [Monitoring with Pprof](pprof-tutorial.md)
   - [controller-gen CLI](controller-gen.md)
   - [completion](completion.md)
   - [Artifacts](artifacts.md)