Add dev/stg/prod environments with per-env values, configmaps and secrets

- Move env-specific config into environments/<env>/{values,configmap,secret}.yaml
  for both nginx-chart and mysql-chart (dev, stg, prod)
- Make templates env-agnostic: resource names come from values
  (configMap.name, secret.name)
- nginx deployment mounts env ConfigMap and loads env Secret via envFrom
- mysql statefulset reads DB config from ConfigMap, passwords from Secret
- Remove mysql-chart/templates/secret.yaml (secrets are now per-env manifests)
- Add README with layout and deploy commands

mysql-chart/environments/dev/configmap.yaml

@@ -0,0 +1,11 @@
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: mysql-config-dev
+  namespace: dev
+  labels:
+    app: mysql
+    env: dev
+data:
+  MYSQL_DATABASE: demo_dev
+  MYSQL_USER: demo

mysql-chart/environments/dev/secret.yaml

@@ -0,0 +1,12 @@
+# MySQL credentials for the DEV environment (referenced by the StatefulSet).
+# Replace with real values; for production use a sealed/encrypted secret instead
+# of committing plaintext.
+apiVersion: v1
+kind: Secret
+metadata:
+  name: mysql-secret-dev
+  namespace: dev
+type: Opaque
+stringData:
+  MYSQL_PASSWORD: demo123
+  MYSQL_ROOT_PASSWORD: root123

mysql-chart/environments/dev/values.yaml

@@ -0,0 +1,14 @@
+# DEV environment overrides for mysql-chart
+namespace: dev
+
+image:
+  tag: "8.4"
+
+storage:
+  size: 1Gi
+
+configMap:
+  name: mysql-config-dev
+
+secret:
+  name: mysql-secret-dev

mysql-chart/environments/prod/configmap.yaml

@@ -0,0 +1,11 @@
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: mysql-config-prod
+  namespace: prod
+  labels:
+    app: mysql
+    env: prod
+data:
+  MYSQL_DATABASE: demo_prod
+  MYSQL_USER: demo

mysql-chart/environments/prod/secret.yaml

@@ -0,0 +1,12 @@
+# MySQL credentials for the PROD environment (referenced by the StatefulSet).
+# Replace with real values; for production use a sealed/encrypted secret instead
+# of committing plaintext.
+apiVersion: v1
+kind: Secret
+metadata:
+  name: mysql-secret-prod
+  namespace: prod
+type: Opaque
+stringData:
+  MYSQL_PASSWORD: prod123
+  MYSQL_ROOT_PASSWORD: prodroot123

mysql-chart/environments/prod/values.yaml

@@ -0,0 +1,14 @@
+# PROD environment overrides for mysql-chart
+namespace: prod
+
+image:
+  tag: "8.4"
+
+storage:
+  size: 5Gi
+
+configMap:
+  name: mysql-config-prod
+
+secret:
+  name: mysql-secret-prod

mysql-chart/environments/stg/configmap.yaml

@@ -0,0 +1,11 @@
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: mysql-config-stg
+  namespace: stg
+  labels:
+    app: mysql
+    env: stg
+data:
+  MYSQL_DATABASE: demo_stg
+  MYSQL_USER: demo

mysql-chart/environments/stg/secret.yaml

@@ -0,0 +1,12 @@
+# MySQL credentials for the STG (staging) environment (referenced by the StatefulSet).
+# Replace with real values; for production use a sealed/encrypted secret instead
+# of committing plaintext.
+apiVersion: v1
+kind: Secret
+metadata:
+  name: mysql-secret-stg
+  namespace: stg
+type: Opaque
+stringData:
+  MYSQL_PASSWORD: stg123
+  MYSQL_ROOT_PASSWORD: stgroot123

mysql-chart/environments/stg/values.yaml

@@ -0,0 +1,14 @@
+# STG (staging) environment overrides for mysql-chart
+namespace: stg
+
+image:
+  tag: "8.4"
+
+storage:
+  size: 2Gi
+
+configMap:
+  name: mysql-config-stg
+
+secret:
+  name: mysql-secret-stg

mysql-chart/templates/secret.yaml

@@ -1,9 +0,0 @@
-apiVersion: v1
-kind: Secret
-metadata:
-  name: mysql-secret
-  namespace: {{ .Values.namespace }}
-type: Opaque
-stringData:
-  MYSQL_ROOT_PASSWORD: {{ .Values.mysql.rootPassword }}
-  MYSQL_PASSWORD: {{ .Values.mysql.password }}

mysql-chart/templates/statefulset.yaml

@@ -1,6 +1,6 @@
 apiVersion: apps/v1
 kind: StatefulSet
-metadata: 
+metadata:
   name: mysql
   namespace: {{ .Values.namespace }}
 spec:
@@ -15,15 +15,20 @@ spec:
       containers:
       - name: mysql
         image: "{{ .Values.image.repository }}:{{ .Values.image.tag }}"
+        envFrom:
+        - configMapRef:
+            name: {{ .Values.configMap.name }}
         env:
-        - name: MYSQL_DATABASE
-          value: {{ .Values.mysql.database }}
-        - name: MYSQL_USER
-          value: {{ .Values.mysql.username }}
         - name: MYSQL_PASSWORD
-          valueFrom: {secretKeyRef: {name: mysql-secret,key: MYSQL_PASSWORD}}
+          valueFrom:
+            secretKeyRef:
+              name: {{ .Values.secret.name }}
+              key: MYSQL_PASSWORD
         - name: MYSQL_ROOT_PASSWORD
-          valueFrom: {secretKeyRef: {name: mysql-secret,key: MYSQL_ROOT_PASSWORD}}
+          valueFrom:
+            secretKeyRef:
+              name: {{ .Values.secret.name }}
+              key: MYSQL_ROOT_PASSWORD
         volumeMounts:
         - name: mysql-data
           mountPath: /var/lib/mysql

mysql-chart/values.yaml

@@ -1,12 +1,31 @@
-namespace: prod
+# Base (default) values for mysql-chart.
+#
+# Environment-specific overrides live in environments/<env>/values.yaml and are
+# merged on top of this file at deploy time:
+#
+#   helm upgrade --install mysql ./mysql-chart -n <namespace> --create-namespace \
+#     -f mysql-chart/environments/<env>/values.yaml
+#
+# Available environments: dev, stg, prod
+#
+# NOTE: database credentials are NOT stored here. They live in the environment
+# secret (environments/<env>/secret.yaml) and the non-secret config lives in
+# the environment ConfigMap (environments/<env>/configmap.yaml).
+
+namespace: dev
+
 image:
   repository: mysql
   tag: "8.4"
-mysql:
-  database: demo
-  username: demo
-  password: demo123
-  rootPassword: root123
+
 storage:
   storageClass: nfs-client
   size: 1Gi
+
+# Names of the ConfigMap / Secret created by environments/<env>/configmap.yaml
+# and environments/<env>/secret.yaml
+configMap:
+  name: mysql-config-dev
+
+secret:
+  name: mysql-secret-dev