Why docker container always restarting? - docker

Question

I run a container in the background using:
docker run --restart always --name lnmp -v /Users/gedongdong/web:/var/www/ -itd lnmp
dockerfile:
FROM alpine:edge
LABEL author=gedongdong2010#163.com
RUN mkdir -p /run/nginx && mkdir -p /shell
RUN echo http://mirrors.aliyun.com/alpine/edge/main > /etc/apk/repositories && \
echo http://mirrors.aliyun.com/alpine/edge/community >> /etc/apk/repositories && \
apk update && apk add --no-cache nginx
COPY vhosts.conf /etc/nginx/conf.d/
COPY start.sh /shell
RUN chmod -R 777 /shell
EXPOSE 80 443 6379
CMD ["/shell/start.sh"]
start.sh:
nginx -c /etc/nginx/nginx.conf
tail -f /dev/null
vhosts.conf:
server {
listen 80;
server_name docker.test;
root /var/www;
index index.html;
}
when i use docker ps -a:
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
3a3910c0dc29 lnmp "/shell/start.sh" 16 minutes ago Restarting (1) 50 seconds ago lnmp
docker ps -a
Why is my container always restarting?

Answer 1

Add #!/bin/sh to your start.sh file
#!/bin/sh
nginx -c /etc/nginx/nginx.conf
tail -f /dev/null
Why the container was always restarting:
As Henry has pointed out in his comments, your setting --restart always told so. In general, keep in mind that when the PID 1 of the container stops/crashes, then the container exits. For example your container shows something like this:
(notice the PID 1 line, where the problem was)
docker container exec -it lnmp top -n 1 -b
Mem: 2846060K used, 3256768K free, 62108K shrd, 83452K buff, 1102096K cached
CPU: 2% usr 2% sys 0% nic 95% idle 0% io 0% irq 0% sirq
Load average: 0.09 0.24 0.27 1/892 41
PID PPID USER STAT VSZ %VSZ CPU %CPU COMMAND
10 9 nginx S 15372 0% 0 0% nginx: worker process
12 9 nginx S 15372 0% 5 0% nginx: worker process
17 9 nginx S 15372 0% 1 0% nginx: worker process
11 9 nginx S 15372 0% 7 0% nginx: worker process
18 9 nginx S 15372 0% 5 0% nginx: worker process
15 9 nginx S 15372 0% 4 0% nginx: worker process
14 9 nginx S 15372 0% 1 0% nginx: worker process
16 9 nginx S 15372 0% 4 0% nginx: worker process
9 1 root S 14924 0% 6 0% nginx: master process nginx -c /etc/nginx/nginx.conf
1 0 root S 1592 0% 1 0% {start.sh} /bin/sh /shell/start.sh
34 0 root R 1532 0% 4 0% top -n 1 -b
13 1 root S 1524 0% 2 0% tail -f /dev/null

Answer 2

For me, it happened because of the permission issue. My machine's password was changed and in the Docker machine, it was not updated.
To debug it in terminal write the code below:
logs <your container's name>