下面两个 location ,

(1)后面如果是 / ,访问的路径 :

ip:端口/index.html  即可访问到 /usr/share/nginx/html/vue 下面的网页
(2)如果后面有东西,访问的路径:

ip:端口/app/dist/index.html  但是 nginx 找的路径,是:/usr/share/nginx/html/vue/app/dist  

是把  app/dist 拼接在 root 下的目录最后面的,而不是前面的

server {
listen 80;
listen [::]:80;
server_name localhost;

#access_log /var/log/nginx/host.access.log main;

location / {
root /usr/share/nginx/html/vue;
index index.html index.htm;
}

location /app/dist/ {
root /usr/share/nginx/html/vue;
index index.html index.htm;
}
……
}