本文的主线 环境 => 服务=> 概念 => 目录 => 体系
环境
vagrant up
pipenv run ansible-playbook playbooks/init.yml
pipenv run ansible-playbook playbooks/zsh.yml
pipenv run ansible-playbook playbooks/redis.yml
sudo apt install -y nginx
服务
ls -l /etc/systemd/system/multi-user.target.wants
cat /etc/systemd/system/multi-user.target.wants/nginx.service
[Unit]
Description=A high performance web server and a reverse proxy server
After=network.target
[Service]
Type=forking
PIDFile=/run/nginx.pid
ExecStartPre=/usr/sbin/nginx -t -q -g 'daemon on; master_process on;'
ExecStart=/usr/sbin/nginx -g 'daemon on; master_process on;'
ExecReload=/usr/sbin/nginx -g 'daemon on; master_process on;' -s reload
ExecStop=-/sbin/start-stop-daemon --quiet --stop --retry QUIT/5 --pidfile /run/nginx.pid
TimeoutStopSec=5
KillMode=mixed
[Install]
WantedBy=multi-user.target
- Description
systemctl list-units | grep nginx
# redis.service loaded active running A high performance web server and a reverse proxy server
- After
man systemd.unit
# After=
# A space-separated list of unit names. Configures ordering dependencies between units
- Type
man systemd.service
# Type=
# Configures the process start-up type for this service unit. One of simple, forking, oneshot, dbus, notify or idle
# If set to forking, it is expected that the process configured with ExecStart= will call fork() as part of its start-up
- PIDFile
man systemd.service
# PIDFile=
# Takes an absolute path referring to the PID file of the service. Usage of this option is recommended for services where Type= is set to forking
ps -ef | grep nginx
cat /run/nginx.pid
grep pid /etc/nginx/nginx.conf
- ExecStart & ExecStop
Linux Kernel
https://github.com/torvalds/linux/search?q=%22define+SIGTERM%22
SIGTERM vs SIGKILL: What's the Difference?
https://linuxhandbook.com/sigterm-vs-sigkill/#:~:text=Though%20both%20of%20these%20signals,cannot%20be%20handled%20or%20blocked.
- TimeoutStopSec & Restart
cat /opt/services/redis/redis-server.pid
sudo killall redis-server
cat /opt/services/redis/redis-server.pid
- Service Unit & Target Unit
systemctl list-units
systemctl list-units | wc -l
systemctl list-units --type=service
systemctl list-units --type=target
概念
ps -ef | head -n 2
# UID PID PPID C STIME TTY TIME CMD
# root 1 0 0 17:21 ? 00:00:01 /sbin/init
vim fork.c
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
int main()
{
printf("start\n");
pid_t pid;
pid = fork();
switch (pid)
{
case -1:
return 1;
case 0:
printf("this is the child\n");
break;
default:
printf("this is the parent\n");
break;
}
printf("sleep\n");
int m = 300;
while (m--)
{
sleep(1);
}
return 0;
}
gcc fork.c -o fork
./fork &
# start
# this is the parent
# sleep
# this is the child
# sleep
ps -ef | grep fork
| 现在 | 过去 | |
|---|---|---|
| 交互 | service | service |
| 实现 | systemctl | init | systemv |
| 手册 | man init | man systemd |
man systemd
# systemd is a system and service manager for Linux operating systems. When run as first process on boot (as PID 1), it acts as init system that brings up and maintains userspace services.
# For compatibility with SysV, if systemd is called as init and a PID that is not 1
目录
ls -l /etc/systemd/system/multi-user.target.wants/nginx.service
# lrwxrwxrwx 1 root root 33 Jan 14 15:16 /etc/systemd/system/multi-user.target.wants/nginx.service -> /lib/systemd/system/nginx.service
sudo systemctl disable nginx.service
ls -l /etc/systemd/system/multi-user.target.wants/
sudo systemctl enable nginx.service
ls -l /etc/systemd/system/multi-user.target.wants/
体系
image.png
sudo journalctl
sudo journalctl -u nginx.service -f
timedatectl
timedatectl set-timezone Asia/Shanghai
hostnamectl
localectl
loginctl list-sessions
loginctl list-users
systemd-analyze blame
sudo systemctl reboot
sudo apt install -y apt-file
apt-file update
apt-file search timedatectl
apt-file search systemctl
网友评论