Dolphin Scheduler is a distributed and easy-to-expand visual DAG workflow scheduling system, dedicated to solving the complex dependencies in data processing, making the scheduling system out of the box for data processing.
**Note**: You must be specify `POSTGRESQL_HOST``POSTGRESQL_PORT``POSTGRESQL_DATABASE``POSTGRESQL_USERNAME``POSTGRESQL_PASSWORD``ZOOKEEPER_QUORUM` when start a standalone dolphinscheduler server.
The Dolphin Scheduler image uses several environment variables which are easy to miss. While none of the variables are required, they may significantly aid you in using the image.
**`POSTGRESQL_HOST`**
This environment variable sets the host for PostgreSQL. The default value is `127.0.0.1`.
**Note**: You must be specify it when start a standalone dolphinscheduler server. Like `master-server`, `worker-server`, `api-server`, `alert-server`.
**`POSTGRESQL_PORT`**
This environment variable sets the port for PostgreSQL. The default value is `5432`.
**Note**: You must be specify it when start a standalone dolphinscheduler server. Like `master-server`, `worker-server`, `api-server`, `alert-server`.
**`POSTGRESQL_USERNAME`**
This environment variable sets the username for PostgreSQL. The default value is `root`.
User data directory path, self configuration, please make sure the directory exists and have read write permissions. The default value is `/tmp/dolphinscheduler`
This environment variable sets xls file path for `alert-server`. The default value is `/tmp/xls`.
**`MAIL_SERVER_HOST`**
This environment variable sets mail server host for `alert-server`. The default value is empty.
**`MAIL_SERVER_PORT`**
This environment variable sets mail server port for `alert-server`. The default value is empty.
**`MAIL_SENDER`**
This environment variable sets mail sender for `alert-server`. The default value is empty.
**`MAIL_USER=`**
This environment variable sets mail user for `alert-server`. The default value is empty.
**`MAIL_PASSWD`**
This environment variable sets mail password for `alert-server`. The default value is empty.
**`MAIL_SMTP_STARTTLS_ENABLE`**
This environment variable sets SMTP tls for `alert-server`. The default value is `true`.
**`MAIL_SMTP_SSL_ENABLE`**
This environment variable sets SMTP ssl for `alert-server`. The default value is `false`.
**`MAIL_SMTP_SSL_TRUST`**
This environment variable sets SMTP ssl truest for `alert-server`. The default value is empty.
**`ENTERPRISE_WECHAT_ENABLE`**
This environment variable sets enterprise wechat enable for `alert-server`. The default value is `false`.
**`ENTERPRISE_WECHAT_CORP_ID`**
This environment variable sets enterprise wechat corp id for `alert-server`. The default value is empty.
**`ENTERPRISE_WECHAT_SECRET`**
This environment variable sets enterprise wechat secret for `alert-server`. The default value is empty.
**`ENTERPRISE_WECHAT_AGENT_ID`**
This environment variable sets enterprise wechat agent id for `alert-server`. The default value is empty.
**`ENTERPRISE_WECHAT_USERS`**
This environment variable sets enterprise wechat users for `alert-server`. The default value is empty.
**`FRONTEND_API_SERVER_HOST`**
This environment variable sets api server host for `frontend`. The default value is `127.0.0.1`.
**Note**: You must be specify it when start a standalone dolphinscheduler server. Like `api-server`.
**`FRONTEND_API_SERVER_PORT`**
This environment variable sets api server port for `frontend`. The default value is `123451`.
**Note**: You must be specify it when start a standalone dolphinscheduler server. Like `api-server`.
## Initialization scripts
If you would like to do additional initialization in an image derived from this one, add one or more environment variable under `/root/start-init-conf.sh`, and modify template files in `/opt/dolphinscheduler/conf/*.tpl`.
For example, to add an environment variable `API_SERVER_PORT` in `/root/start-init-conf.sh`:
```
export API_SERVER_PORT=5555
```
and to modify `/opt/dolphinscheduler/conf/application-api.properties.tpl` template file, add server port: