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connect() to 10.2.20.170:1009 failed (13: Permission denied) while connecting to upstream

现这个错误是因为selinux， linux安全增强的补丁导致的。

解决方法是禁用selinux的安全增强， 可以使用命令 setenforce 0来临时禁用，或者通过修改配置文件/etc/sysconfig/selinux 添加 SELINUX=disabled来永久禁用

然后重启 reboot

# This file controls the state of SELinux on the system.# SELINUX= can take one of these three values:#     enforcing - SELinux security policy is enforced.#     permissive - SELinux prints warnings instead of enforcing.#     disabled - No SELinux policy is loaded.SELINUX=disabled# SELINUXTYPE= can take one of these two values:#     targeted - Targeted processes are protected,#     mls - Multi Level Security protection.SELINUXTYPE=targeted