[Bug]: Entrypoint for Docker image erases config file

[davidlago]

Describe the bug

After #1130 was merged, this line completely wipes out the configuration file of the docker container on startup.

To reproduce

docker run -it -p 9200:9200 -e "discovery.type=single-node" opensearchstaging/opensearch:1.2.4

as 1.2.4 is the first image built with this entrypoint.

Expected behavior

Container should start up successfully.

Screenshots

If applicable, add screenshots to help explain your problem.

Host / Environment

MacOS, docker.

Additional context

No response

Relevant log output

No response

[peterzhuamazon]

Taking a look.

[peterzhuamazon]

The issue is due to that:

Reading from and writing to opensearch.yml in the same command line is error-prone. sed is trying to read from the file at the same time that tee wants to truncate it and write to it.