@startuml

title Article

cloud web

node nodejs {
    TCP -right- [express]
    [showdown]
}

package data {
    package "2019/06/18" {
        component index [
            index.md
            image.png
            ...
        ]
    }
}

web -down-> TCP : 1. /2019/06/18/title
express -down-> index : 2. fetch
index -up-> showdown : 3. markdown
showdown -left-> express : 4. html
express -up-> web : 5. html

@enduml