Trouble understanding one part of the what-is-kubernetes documentation

General Discussions
1

Hi everyone,

Firstly, if this is the wrong place to post such a basic question then please let me know.

Overall the documentation on the Kubernetes page is clear, I am just having trouble understanding the following statement, from this page:

Dev and Ops separation of concerns: create application container images at build/release time rather than deployment time, thereby decoupling applications from infrastructure.

This is confusing for me, because in my limited history with devops I have only seen deployments occurring right after the build occurs. So how is it possible to decouple these two things? I am probably misinterpreting the statement or missing some piece of information.
Could anyone please provide a concrete example of how Kubernetes allows one to separate image creation from the deployment, and what are the benefits?

2

We’re using docker swarm still, (not k8s), but our example applies just the same.

  1. Our build pipeline (gitlab) creates a docker image after a merge - this is the dev part

  2. the image can be deployed, at anytime and anywhere (docker swarm, k8s) from the gitlab registry - this is the ops part. e.g. our registry has images for all builds completed in the past 2 weeks. I can deploy one of those images at any point in time to docker or k8s.

  3. its possible to configure your ci/cd to immediately deploy a built image as part of the dev workflow. This appears to be what you’re mentioning “deployments right after build”, but there’s no requirement to do this.

1 Like
3

perfect thanks