(September 20, 2020) How do you handle a system deployed to Docker Swarm, with multiple Stacks, where a container in one Stack must communicate with a container in another Stack? For example, you may have a database Stack, and an application layer Stack, where the application needs to communicate with the database. It's simplest to put both into the same Stack. But it's a best practice for the database to stay running, and to separately bring the application up and down to deploy updates. Therefore it's best to use separate Stacks for each layer, raising the question of how will the application containers find the database containers.
(May 30, 2020) Launching a Docker Swarm on EC2 instances is relatively easy, but of course there are pitfalls. One involves deploying a service to the swarm, but getting an error message about being unable to access the container image from the ECR registry.
(May 21, 2020) Docker is a cool system for deploying applications as reusable containers, and Docker Swarm is a Docker Orchestrator that let's us scale the number of containers across multiple machines. Multipass is a very light weight virtual machine manager application running on Windows, Linux and macOS, that let's us easily set up multiple Ubuntu instances on our laptop at low performance impact. Therefore Multipass can serve as a means to easily experiment with Docker Swarm on your laptop, learning how it works, setting up networks, etc.