Really appreciate your help!
Found the following dockerized-app-snap repository on GitHub which really helped me to create a Snap that run a dockerzied app through the content-interface shared by the docker snap.
Attached my snapcraft.yaml for anyone who trying to do something similar:
Some my-app Description.
'docker-wrapper' : bin/
command: docker-wrapper docker <any docker command ps/pull/run>
plugs: [docker-executables, docker-cli]
You can find general explanation on Snap Interfaces(plugs and slots) here In short, an interface consists of a connection between a slot and a plug. The slot is the provider of the interface while the plug is the consumer. In my case, the docker snap has 2 interfaces that it provides(slots) which my-app consumes(plugs) - the docker interface under the docker-cli plug and the content interface under docker-executables plug.
Regarding the question if Docker must be installed via Snap. Because my-app snap uses the docker snap interfaces, the answer it yes. But I’m not sure if it’s conflict with a docker installed on the machine. will update when I have the answer.
Hoped I helped somebody!