[doc] dashboard docker relative clarity
Fixes
### Motivation
The original document may mislead users into thinking that there is no any ready-made docker image and building one from scratch.
@@ -12,22 +12,21 @@ A [Django](https://www.djangoproject.com) web app is used to render the collecte
## Install
-The easiest way to use the dashboard is to run it inside a [Docker](https://www.docker.com/products/docker) container. A {@inject: github:`Dockerfile`:/dashboard/Dockerfile} to generate the image is provided.
-
-To generate the Docker image:
+The easiest way to use the dashboard is to run it inside a [Docker](https://www.docker.com/products/docker) container.
```shell
-$ docker build -t apachepulsar/pulsar-dashboard dashboard
+$ SERVICE_URL=http://broker.example.com:8080/
+$ docker run -p 80:80 \
+ -e SERVICE_URL=$SERVICE_URL \
+ apachepulsar/pulsar-dashboard:{{pulsar:version}}
```
-To run the dashboard:
+The {@inject: github:`Dockerfile`:/dashboard/Dockerfile} can be found in `dashboard` directory, you can build a image from scratch also:
```shell
-$ SERVICE_URL=http://broker.example.com:8080/
-$ docker run -p 80:80 \
- -e SERVICE_URL=$SERVICE_URL \
- apachepulsar/pulsar-dashboard
+$ docker build -t apachepulsar/pulsar-dashboard dashboard
```
+
If token authentication is enabled:
> Provided token should have super-user access.
```shell
