[TheIronYuppie]

The best way to do blue/green is put them behind a single endpoint. So, if your endpoint is 'app: node-app', then you put the label 'app: node-app' on BOTH your existing version, and your future version, and target all traffic to a service with the selector 'app: node-app'.

Then, you slowly start to spin up your new instances from 1 -> 10 -> 100 (or whatever). The traffic will split automatically because both apps have the same label/selector, and you control the amount by how many instances of each you have.

Disclosure: I work at Google on Kubernetes

[pdeva1]

does kubernetes take care of 'connection draining', ie making sure requests in flight are completed before killing traffic to an instance?

[sporkland]

Sort of a blend. It will send a sigterm to your process first which should be your signal to start draining and exit when they are done. If you don't finish within a configurable timeout then sigkill is sent.

[x0rg]

I was wondering how to make this automated through some sort of pipeline that needs a human to click "go on with the next X % of the rollout and how I would do it with kubectl without too much pain.

[sporkland]

We've been doing this with multiple deployments (e.g. 1, half, all) and updating the deployments sequentially when the previous one looked good. (these are all fronted by one service).