Is it possible to have multiple clusters without duplicating `cluster.yaml`?

[sevro]

I am trying to setup a development, staging, production CI/CD pipeline for cortex services and if I try to spin up multiple clusters with the same cluster.yaml even in different environments I get:

error: a cluster named "$MY_CLUSTER" already created and updated in $MY_REGION

I see that this was at least considered before in "Consider how to merge CLI environment config with cluster config for multiple clusters #712" but I do not see it reflected as resolved in the docs which still has an example of multiple clusters using different cluster.yaml files. It will definitely be unnecessarily confusing to have cluster-dev.yaml, cluster-staging.yaml, and cluster-prod.yaml on all three branches all out of sync with eachother any of which could be accidentally deployed/updated breaking things.

Or was this resolved and it is just not reflected in the docs? Or am I missing some other better way to set this up?

[sevro]

Also I am currently on version 0.35 if that makes a difference, but I see no difference in the docs about this.

[deliahu]

@sevro the best way to accomplish what you're trying to do would be do use some sort of templating to generate cluster.yaml files. There are a few ways you can do this. For example you could have a cluster.yaml that looks like this:

cluster_name: cortex-${ENV_NAME}
region: us-west-2
...

And then in your CI environment, you can set the ENV_NAME environment variable to dev/staging/prod, and then use envsubst to generate the files (e.g. something like envsubst < cluster-template.yaml > cluster-prod.yaml.

Alternatively, you can use something like Jinja, or you could write a Python script which takes in an argument for the name of your environment and writes the appropriate cluster.yaml file (or it could take no args and just write all three).

[sevro]

That is a solid solution, I was worried about the complexity of pulling in a whole templeting engine but envsubst would be elegant for what I'm trying to do. Thanks!