[系统运维]dockerfile命令CMD与ENTRYPOINT：替换与拼接

# CMD
vim testCMD
	# 写入
	FROM centos
	CMD ["ls","-a"]
docker build -f testCMD -t testcmd:1.0
docker run $(docker images testcmd -q)

# ENTRYPOINT
vim testENTRYPOINT
	# 写入
	FROM centos
	ENTRYPOINT ["ls","-a"]
docker build -f testENTRYPOINT -t testentrypoint:1.0
docker run $(docker images testentrypoint -q)

# CMD与ENTRYPOINT运行结果如下
.
..
.dockerenv
bin
dev
etc
……

# 当在运行ls -al时
drwxr-xr-x  1 root root 4096 Mar  4 12:28 .
drwxr-xr-x  1 root root 4096 Mar  4 12:28 ..
-rwxr-xr-x  1 root root    0 Mar  4 12:28 .dockerenv
lrwxrwxrwx  1 root root    7 Nov  3  2020 bin -> usr/bin
drwxr-xr-x  5 root root  340 Mar  4 12:28 dev
drwxr-xr-x  1 root root 4096 Mar  4 12:28 etc
……

# CMD run指令后加-l报错，需加ls -al
docker run $(docker images testcmd -q) ls -al
# ENTRYPOINT run指令后加-l，运行成功
docker run $(docker images testentrypoint -q) -l

综上所述：CMD 是替换，ENTRYPOINT是拼接