Failed to parse PID from file

How to fix the NGINX error “Failed to read PID from file”, quick and easy

以下是有关如何修复错误消息的提示：

nginx.service: Failed to read PID from file /run/nginx.pid: Invalid argument
或者
openresty.service: Failed to parse PID from file /run/openresty.pid: Invalid argument

此行为是一个已知错误，由nginx和systemd之间的竞争条件引起。 Systemd期望在nginx有时间创建之前填充PID文件。要修复错误，您必须创建该文件。

Step 1. 创建目录：/etc/systemd/system/nginx.service.d

Create a directory named nginx.service.d in /etc/systemd/system/:

mkdir /etc/systemd/system/nginx.service.d

Step 2. Print data to file

printf "[Service]\nExecStartPost=/bin/sleep 0.1\n" > /etc/systemd/system/nginx.service.d/override.conf

确保在其自己的行上输入>之后的字符串，以便printf将其输出写入配置文件：

 /etc/systemd/system/nginx.service.d/override.conf

Step 3. Reload the daemon

Reload systemd manager configuration:

systemctl daemon-reload

This will rerun all generators, reload all unit files and recreate the entire systemd dependency tree.

Step 4. Restart NGINX

This line will restart NGINX for you:

systemctl restart nginx

The error should be fixed now.

An alternative workaround

Another workaround is removing the PIDFile option and adding the line:

ExecStopPost=/bin/rm -f /run/nginx.pid

https://www.cloudinsidr.com/content/heres-fix-nginx-error-failed-read-pid-file-linux/