You can tune the configuration by declaring environment variables in your values.yaml file (see how to deploy with Helm).
For instance, if you need to configure master, add a env section in your values.yaml file with the desired environment variables:
...
master:
...
env:
MY_VALUE:
value: my-value
...
For advanced configuration, using secrets for instance, you can define the environment variables following the Kubernetes EnvVar syntax.