SSH is the Swiss Amy Knife of system administration and provides the easiest way to manage a system remotely. When running containers, there is typically someway to connect to a container’s shell from a client that communicates through an API like Docker or by using an SSH solution which is how Apcera does it. Some applications that run in containers may require SSH access to communicate with other containers or services. For example, Hadoop is a popular cluster application that uses a distributed filesystem spread across many nodes and communicates with each other via SSH. Let’s take a look on how to setup an SSH server running inside a capsule (a minimal OS container) on the Apcera Platform.
I like to take a break from my usual Docker blog posts and discuss the Apcera Cloud Platform. The Apcera Cloud Platform runs containerized workloads such as Docker images or applications from source code in a clustered environment. For the past several weeks, I have been playing with Docker Swarm and spent time researching how to put this blog into production on it. Life has been very difficult for this migration because Swarm requires a lot of handholding and lacks the failover automation that I need. I began researching the Apcera Platform and tried out the community edition that users can try for free. The areas that I focused on for my needs regard ease of use and workload portability.
I have been a hardcore CentOS user for many years now. I enjoyed its minimal install to create a light environment, intuitive installation process, and it’s package manager. Docker is the most popular container format today and provides developers and enthusiasts with an easy way to run workloads in containerized environments. I started using Docker in production at home for about a year now for services such as Plex Media Server, Web Server for this blog, ZNC, MineCraft, and MySQL to name a few. A Dockerfile is a set of instructions used to create a Docker image. I invested many hours creating perfect Dockerfiles using CentOS and Fedora to make deployments simple on any operating system. However, a personal revolution was brewing.