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

nginx-chart/templates/deployment.yaml

@@ -18,9 +18,21 @@ spec:
         app: nginx
     spec:
       imagePullSecrets:
-      - name: harbor-secret
+      - name: {{ .Values.imagePullSecrets }}
       containers:
         - name: nginx
           image: "{{ .Values.image.repository }}:{{ .Values.image.tag }}"
+          imagePullPolicy: {{ .Values.image.pullPolicy }}
           ports:
-            - containerPort: 80
+            - containerPort: 80
+          envFrom:
+            - secretRef:
+                name: {{ .Values.secret.name }}
+          volumeMounts:
+            - name: nginx-config
+              mountPath: /etc/nginx/conf.d/default.conf
+              subPath: default.conf
+      volumes:
+        - name: nginx-config
+          configMap:
+            name: {{ .Values.configMap.name }}