Upgrading microservices

Deploying and securing microservices is just the beginning. As you develop and evolve your system, you'll need to upgrade your microservices. There are many important considerations regarding how to go about it that we will discuss later (versioning, rolling updates, blue-green, and canary). Kubernetes provides direct support for many of these concepts out of the box and the ecosystem built on top of it to provide many flavors and opinionated solutions.

The goal is often zero downtime and safe rollback if a problem occurs. Kubernetes deployments provide the primitives, such as updating a deployment, pausing a roll-out, and rolling back a deployment. Specific workflows are built on these solid foundations.
The mechanics of upgrading a service typically involve upgrading its image to a new version and sometimes changes to its support resources and access: volumes, roles, quotas, limits, and so on.