Allow to add image pull secret

[tony84727]

Is this a BUG REPORT or FEATURE REQUEST?

FEATURE REQUEST

Versions

MySQL Operator Version: 0.3.0

What happened?

I'm testing my fork of mysql operator. I pushed mysql-operator and mysql-agent to a private image registry. To allow Kubernetes to pull the images, I need to specify imagePullSecrets to both the operator pod and Mysql pods.

What you expected to happen?

The helm template should allow users to specify additional imagePullSecrets for deploying the operator. The Cluster might also need to allow users to specify imagePullSecrets too, the operator then propagate those secrets to spawned pods.

How to reproduce it (as minimally and precisely as possible)?

1. Host images on a private registry
2. Try to deploy the operator. e.g. helm install mysql-operator -n mysql-operator mysql-operator/ --set image.registry=<private-registry> (helm 3)