mysql: Use separate file for secret + remove duplicated mysql name

mysql/kustomize/base/mysql_statefulset.yaml

@@ -31,7 +31,7 @@ spec:
         - name: MYSQL_ROOT_PASSWORD
           valueFrom:
             secretKeyRef:
-              name: mysql-secret
+              name: secret
               key: mysql-root-password
         volumeMounts:
         - name: mysql-data

mysql/kustomize/base/phpmyadmin_deployment.yaml

@@ -27,12 +27,12 @@ spec:
         - name: PMA_HOST
           valueFrom:
             configMapKeyRef:
-              name: mysql-configmap
+              name: configmap
               key: mysql-server
         - name: PMA_USER
           value: root
         - name: PMA_PASSWORD
           valueFrom:
             secretKeyRef:
-              name: mysql-secret
+              name: secret
               key: mysql-root-password

mysql/kustomize/overlays/default/kustomization.yaml

@@ -26,10 +26,9 @@ patches:
 - path: replica.yaml
 
 configMapGenerator:
-- name: mysql-configmap
+- name: configmap
   env: mysql-configmap.properties
 
 secretGenerator:
-- name: mysql-secret
+- name: secret
-  literals:
+  env: mysql-secret.properties
-  - mysql-root-password=root

mysql/kustomize/overlays/default/mysql-secret.properties

@@ -0,0 +1 @@
+mysql-root-password=root