[Improvement][HELM] add driver-class-name (#14614)

Signed-off-by: Gallardot <gallardot@apache.org>
Co-authored-by: xiangzihao <460888207@qq.com>
Co-authored-by: Eric Gao <ericgao.apache@gmail.com>

deploy/kubernetes/dolphinscheduler/templates/_helpers.tpl

@@ -175,6 +175,14 @@ Create a database environment variables.
       name: {{ include "dolphinscheduler.fullname" . }}-externaldb
       key: database-password
       {{- end }}
+- name: SPRING_DATASOURCE_DRIVER-CLASS-NAME
+  {{- if .Values.postgresql.enabled }}
+  value: {{ .Values.postgresql.driverClassName }}
+  {{- else if .Values.mysql.enabled }}
+  value: {{ .Values.mysql.driverClassName }}
+  {{- else }}
+  value: {{ .Values.externalDatabase.driverClassName | quote }}
+  {{- end }}
 {{- end -}}
 
 {{/*

deploy/kubernetes/dolphinscheduler/values.yaml

@@ -43,6 +43,7 @@ postgresql:
   postgresqlUsername: "root"
   postgresqlPassword: "root"
   postgresqlDatabase: "dolphinscheduler"
+  driverClassName: "org.postgresql.Driver"
   params: "characterEncoding=utf8"
   persistence:
     enabled: false
@@ -51,6 +52,7 @@ postgresql:
 
 mysql:
   enabled: false
+  driverClassName: "com.mysql.cj.jdbc.Driver"
   auth:
     username: "ds"
     password: "ds"
@@ -82,6 +84,7 @@ externalDatabase:
   password: "root"
   database: "dolphinscheduler"
   params: "characterEncoding=utf8"
+  driverClassName: "org.postgresql.Driver"
 
 ## If not exists external registry, the zookeeper registry will be used by default.
 zookeeper: