Inject a ConfigMap and a Secret as Env Vars

The mailer Deployment in the analytics namespace still has its settings baked into the image. The team wants them moved into the cluster: plain settings in a ConfigMap, the database password in a Secret, both delivered to the containers as environment variables.

Task

• Create a ConfigMap mailer-settings in analytics with exactly these keys: APP_MODE=staging, LOG_LEVEL=debug, REGION=us-east.
• Create a Secret mailer-db in analytics with the key password set to meadow.
• The container of Deployment mailer receives every key of mailer-settings as an environment variable of the same name.
• The same container receives the Secret's password key as the environment variable DATABASE_PASSWORD.
• All 2 replicas of mailer are available with the new configuration.
• Leave the ConfigMap mailer-legacy as it is.

A practice cluster is running on this machine: start with kubectl get deploy,configmap,secret -n analytics.