Nginx failed while connecting to upstream

當我使用 nginx 對 localhost:8080 进行反向代理时，收到 503 响应。检查 nginx error log，发现有：

[crit] 10000#0: *3 connect() to 127.0.0.1:8080 failed (13: Permission denied) while connecting to upstream, client: ***, server: ***, request: "GET /x/ HTTP/1.1", upstream: "http://127.0.0.1:8080/", host: "***"

经过检查，发现是 SELinux 策略阻止了 nginx 访问 上游接口。

可进行如下操作：

sestatus

getenforce

setenforce 0 //臨時禁用

vim /etc/selinux/config //于配置文件中禁用