[docker/cli] `docker run --env-from` option, analogous to the `--volumes-from`

### ROOT CAUSE The issue arises from the absence of a `--env-from` option in Docker's `docker run` command, which prevents containers from inheriting environment variables from other containers, necessitating manual redefinition. ### CODE FIX To implement the `--env-from` option, we'll modify the Docker CLI to accept this new flag and adjust the container runtime to inherit the environment variables from the specified container. **Step-by-Step Explanation:** 1. **Modify the CLI Option Parsing:** - **docker/cli/command.go**: - Add the `--env-from` flag to the `Run` command. - Parse the flag value to capture the source container's name or ID. 2. **Update Container Creation:** - **docker/container.(*ContainerCreateConfig).(*CreateOpts).EnvFrom**: - Introduce a new field to store the `--env-from` value. - Modify the `ContainerCreate` function to include this new field when creating the container. 3. **Retrieve Environment Variables from Source Container:** - **docker/api/client.go**: - Add a new API call to fetch environment variables from a specified container. - Use this API to retrieve the environment variables from the source container. 4. **Apply Environment Variables to New Container:** - **docker/container.(*Container).Create**: - Merge the retrieved environment variables into the new container's environment variables. - Ensure that if an environment variable exists in both the new container and the source, the new container's value takes precedence. 5. **Handle Multiple `--env-from` Flags:** - **docker/cli/command.go**: - Allow multiple `--env-from` flags to inherit variables from multiple containers. - Process each flag sequentially, merging variables and allowing later containers to override earlier ones. 6. **Test the New Feature:** - **docker/test/*_test.go**: - Write unit tests to verify that `--env-from` correctly inherits environment variables. - Ensure that existing functionality remains unaffected. **Example Usage:**

bash
docker run --env-from container_name -it my_image


This command runs `my_image` and inherits environment variables from `container_name`, avoiding the need to manually list each variable.