Help-for-release-actions.md

@@ -210,6 +210,16 @@ Since OTB 9.0 we are providing three dockers per version:
 
 Before building these dockers, as docker download gdal bindings, you must ensure that gdal bindings for correct python version are available at https://www.orfeo-toolbox.org/packages/archives/OTB/ .
 
+Then you can build and push the docker:
+
+```shell
+# for instance for version 9.1.0 on ubuntu 20.04
+docker build -t orfeotoolbox/otb:9.1.0 -f Docker/Dockerfile .
+# ensure all works correctly
+# a "docker login" with correct username and password may be needed
+docker push orfeotoolbox/otb:9.1.0
+```
+
 ### Update documentation
 
 Updating documentation contains multiple steps: