Containers

Containers, specifically Linux containers popularised by Docker, offer a way to package an application and its dependencies in a language agnostic way. The package, a container image, can be versioned and published to a registry. Typically, a descriptor, e.g. Kubernetes’ manifests, are also required to describe how to run the image as a container such as:

• How many instances to run
• The resources to give the container
• Configuration for ingress

Running containers requires orchestration ranging from:

• VM instances with a single container per VM e.g. GCP’s compute engine managed instance group
• A third party PaaS e.g. GCP’s flexible compute engine
• A managed Kubernetes cluster e.g. Google Kubernetes Engine
• A fully managed container environment based on Kubernetes e.g. Google Cloud Run
• A PaaS built with a combination of the above and custom software