Xdebug profiler documentation

documentation/README.md

@@ -12,6 +12,7 @@
 
 - [Local environment](/documentation/local.md)
 - [Profiling code with Blackfire.io](/documentation/blackfire.md)
+- [Profiling code with Xdebug profiler](/documentation/xdebug-profiler.md)
 
 ## Infrastructure
 
@@ -33,5 +34,3 @@
 
 - [Testing and CI](/documentation/testing.md)
 - [PHPstan](/documentation/phpstan.md)
-
-

documentation/xdebug-profiler.md

@@ -0,0 +1,53 @@
+# Profiling code with Xdebug PHP Profiler
+
+Create a modified xdebug.ini to your project's root:
+```ini
+zend_extension=/usr/lib/php83/modules/xdebug.so
+xdebug.mode=profile
+xdebug.output_dir=/app/xdebug
+xdebug.profiler_enable=1
+xdebug.profiler_output_name=cachegrind.out.%p
+xdebug.use_compression=false
+```
+
+Create a `Dockerfile.profile` file in your project's root:
+```bash
+ARG DRUPAL_IMAGE
+FROM ${DRUPAL_IMAGE}
+
+COPY xdebug.ini /etc/php83/conf.d/50_xdebug.ini
+
+RUN mkdir -p /app/xdebug
+```
+
+Modify your `compose.yaml` file:
+
+```diff
+diff --git a/compose.yaml b/compose.yaml
+index 99f55b27..27580975 100644
+--- a/compose.yaml
++++ b/compose.yaml
+@@ -1,7 +1,12 @@
+ services:
+   app:
+     container_name: "${COMPOSE_PROJECT_NAME}-app"
+-    image: "${DRUPAL_IMAGE}"
++    # image: "${DRUPAL_IMAGE}"
++    build:
++      context: .
++      dockerfile: Dockerfile.profile
++      args:
++        DRUPAL_IMAGE: "${DRUPAL_IMAGE}"
+     hostname: "${COMPOSE_PROJECT_NAME}"
+     volumes:
+       - .:/app:delegated
+```
+
+Build the image with the dockerfile and start up the project 
+```bash
+docker compose up --wait --remove-orphans --build`
+```
+
+Load the page you want to profile and check that the log files start to appear in project's `xdebug` folder.
+
+Use [qcachegrind](https://formulae.brew.sh/formula/qcachegrind) (for Mac) or [kcachegrind](https://kcachegrind.github.io/) (for Linux) to open the log files in a GUI.