Support setting custom configurations for all containers #168
Description
A company is developing some containers for different customers and want to use Cumulocity to manage these containers. The containers are the same for different customers, but each customer has their own configurations. And on the same device, the containers can use the same configurations. These configurations should be unchanged when the users update/remove the containers and containers should be able to read and use these configurations.
Maybe we could let the tedge-container-plugin's user define if there are any files/folders that always need to be mounted to all containers. Then the user can manage the config file on Cumulocity using configuration management. Tedge-container-plugin could mount the files/folders for all the containers based on user's choise.
Except volumes, the configuration could also be env variables, ports, network, secrets and so on. It may also be helpful to support these global custom configurations available for all containers.