High Availability is a feature where you have multiple instances of your applications running in parallel to handle increased load or failures.
These two paradigms fit perfectly into Docker Swarm,the built-in orchestrator that comes with Docker.
Deploying your applications like this will improve your uptime which translates to happy users.
For creating a high availability container in the Docker Swarm, you need to deploy a docker service to the swarm with nginx image.
This can be done by using docker swarm create command as specified:
# docker service create --name nginx --publish 80:80 nginx
To explore more about docker swarm and how you could use it to achieve high availability do have a look:
Hope this helps!