[Dockerfile] How to Prevent Docker Container from SSHing

While SSH is a valuable tool for debugging and testing Docker containers, enabling it in production environments is not recommended due to security concerns. To disable SSH in a Docker container, it’s advisable to remove the SSH server during the image building process.

One way to accomplish this is to remove the SSH server during the Docker image building process. For example, if you’re using the alpine base image, you can use the following Dockerfile:

1FROM alpine:latest 
2RUN rm -rf /etc/ssh && mkdir /etc/ssh
3...

If you’re using a different base image, you’ll need to determine the SSH server package name and remove it from the container. For instance, you might use RUN apk del openssh to remove the SSH server from the Docker container.

By following these steps, you can prevent SSH access to your Docker container and help ensure its security in production environments. If you need to perform additional security operations that don’t change often, building a custom base image that includes those steps can be a good option.