Update documentation of certs-gen procedure

indexer-certs-creator/README.md

@@ -1,9 +1,27 @@
-# Certificate creation image build
+# Certificate Creation Image Build
 
-The dockerfile hosted in this directory is used to build the image used to boot Wazuh's single node and multi node stacks.
+The dockerfile hosted in this directory is used to build the image required for generating Wazuh Docker single-node and multi-node certificate files
 
-To create the image, the following command must be executed:
+## Pre-requisites
 
+### QEMU
+
+Set up QEMU to enable building multi-architecture Docker images
+
+Useful documentation:
+
+- https://www.qemu.org/download/
+- https://docs.docker.com/build/building/multi-platform/#qemu
+
+## Procedure
+
+Run the following script to build the wazuh-certs-generator docker image
+
+```console
+./build-image.sh -v <IMAGE_TAG> [-m] [-rg <REGISTRY>]
 ```
-$ docker build -t wazuh/wazuh-certs-generator:0.0.3 .
+
-```
+Replace <IMAGE_TAG> with the new image desired tag.
+Use the `-m` flag to build a multi-architecture image (supports both `amd64` and `arm64`)
+Use the `-rg <REGISTRY>` parameter to specify a custom Docker registry (default is Docker Hub)
+  By default, the script will attempt to push the image to the registry and will only work if credentials are properly configured.

indexer-certs-creator/build-image.sh

@@ -37,7 +37,9 @@ build() {
     set +a
 
     if [ "${MULTIARCH}" ]; then
-        docker buildx bake --file build-image.yml --push --set *.platform=linux/amd64,linux/arm64 --no-cache || clean 1
+        docker buildx bake --file build-image.yml \
+            --set *.platform=linux/amd64,linux/arm64 \
+            --no-cache || clean 1
     else
         docker buildx bake --file build-image.yml --no-cache || clean 1
     fi