报错：

Dot Executable :/usr/bin/dot

File does not exist

Cannot find Grapviz.You should try

@startuml

testdot

@enduml

解决办法：

centos安装的confluence：

yum search graphviz   

yum install graphviz.x86_64

ubuntu 安装的centos：

apt-get  cache graphviz 

apt-get  install graphviz