Google container builder, create new namespace for new branch

Question

I am trying to develop my automation build.

So what we want to achieve is whenever a developer push a code to a new branch, it will create a new namespace in kubernetes based on that branch name. then I will do all deployments in that namespace.

What is the best way to create namespace?

 - name: 'gcr.io/cloud-builders/kubectl'
   args:
     - 'create'
     - 'namespace'
     - '${BRANCH_NAME}

will have a problem when namespace exist. So, I was planning to use file instead then I can apply it via

 - name: 'gcr.io/cloud-builders/kubectl'
   args:
     - 'apply'
     - '-f'
     - 'filename.yaml'

and here is the filename.yaml:

apiVersion: v1
kind: Namespace
metadata:
  name: '${<BRANCH>}'

Now my question is, how to pass this branch name if I go with second approach. If I go with my first approach I do not know how to check whether namespace exist or not.

Please help.

Thanks.

Answer 1

Second approach

Lets say, you are using following filename.yaml file

apiVersion: v1
kind: Namespace
metadata:
  name: $BRANCH

Here, $BRANCH is ENV variable inside your YAML

Now all you need to substitute this variable with ENV value.

$ export BRANCH="demo"; cat filename.yaml | envsubst | kubectl create -f -
namespace "demo" created