This is a tool that can be used to migrate data from an existing index to a new index with updated mappings.
The tool assumes that the index is behind an alias, and that the current index can be made read-only while the data is copied from the current index into a new version of that index. Once the new index has been written, the alias is cut over to the new version.
It is configured GitHub action which build and push docker image to DockerHub repository. Status of the docker build could be checked here.
The Dockerfile in this project builds an intermediate container with an ONBUILD instruction, which will complete the build process when a child container uses this image in a FROM instruction. Such a project requires at least one git commit in its repository, and a file mapping.json in its root directory.