如何在 alpine 中启动 Nginx 服务器：使用 rc-service 命令的最新映像

Question

我正在尝试创建自己的Nginx 图像，使用apline:latest 图像，在修复了很多错误之后，感谢互联网，我设法做到了，一切正常，但问题是当我运行时以下命令：

rc-service nginx status
 * status: stopped

当我尝试启动服务时，它给了我如下所示：

rc-service nginx start
 * WARNING: nginx is already starting

即使服务已停止，第二个命令的输出告诉它已经启动？！

于是我打开了我的docker-machine的localhost，验证服务是否开启，成功出现nginx html页面。

我尝试运行rc-service nginx reload，结果如下：

rc-service nginx reload
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/blkio/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/cpu/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/cpuacct/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/cpuset/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/devices/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/freezer/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/hugetlb/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/memory/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/net_cls/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/net_prio/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/perf_event/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/pids/tasks: Read-only file system
 * nginx: cannot `reload' as it has not been started

这是nginx -t 的输出：

nginx -t
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful

这是less /var/log/nginx/error.log的输出，如下图没有错误：

less: can't open '/var/log/nginx/error.log': No such file or directory

这是我的 dockerfile：

From alpine:latest

COPY nginx.conf ./tmp
COPY index.html ./tmp
COPY run.bash ./tmp
COPY run2.bash ./tmp

RUN apk update && \
    apk add nginx && \
    adduser -D -g 'www' www && \
    mkdir /www && \
    chown -R www:www /var/lib/nginx && \
    chown -R www:www /www && \
    mv /etc/nginx/nginx.conf /etc/nginx/nginx.conf.orig && \
    apk add openrc --no-cache && \
    sh tmp/run.bash

cmd sh tmp/run2.bash

运行.bash：

mv tmp/nginx.conf /etc/nginx/nginx.conf
mv tmp/index.html  /www/index.html

run2.bash：

mkdir /run/openrc
touch /run/openrc/softlevel
mkdir -p /run/nginx
nginx
sh

这是我遵循的指南：

https://wiki.alpinelinux.org/wiki/Nginx

我想知道为什么即使我的 nginx 服务在我的 docker 机器上完美运行，rc-service nginx reload 也无法正常工作，以及为什么rc-service nginx status 告诉 nginx 服务即使没有停止也已停止？

提前致谢。

顺便说一句，当我运行此命令nginx -s reload 时，它可以正常工作。

Answer 1

经过调试和大量试验和错误，我至少找到了一个完美的解决方案，David Maze 的回答非常有帮助，但出于测试 的目的，我需要我的shell 是可访问的，因为当你运行nginx -g "daemon off;" 时，除非你停止命令进程，否则你无法访问你的容器 shell。

无论何时我使用以下命令启动我的容器：

docker run -it -p 80:80 -p 443:443 alpine:latest

我们访问容器shell，我们需要下载nginx server 和openrc 才能使用rc-service 命令行。

/ # apk update
/ # apk add nginx openrc

#ANSWER 1

现在我们将使用以下命令测试 nginx 服务器中是否存在错误：

/ # nginx -t
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: [emerg] open() "/run/nginx/nginx.pid" failed (2: No such file or directory)
nginx: configuration file /etc/nginx/nginx.conf test failed

你可以从我们得到的输出中看到，它告诉你应该创建一个丢失的文件或目录，所以让我们创建那个目录：

/ # ls -la run/
total 8
drwxr-xr-x    2 root     root          4096 Dec 16 10:31 .
drwxr-xr-x    1 root     root          4096 Jan 16 08:12 ..

/ # mkdir /run/nginx/

我们给那个目录我们创建了一些权限：

/ # chown -R nginx:nginx /run/nginx/
/ # chmod 775 /run/nginx/
/ # ls -la /run/
total 12
drwxr-xr-x    1 root     root          4096 Jan 16 08:15 .
drwxr-xr-x    1 root     root          4096 Jan 16 08:12 ..
drwxrwxr-x    2 nginx    nginx         4096 Jan 16 08:15 nginx

现在我们可以很好地使用 nginx 了：

/ # nginx -t
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful

用rc-service命令测试一下我们的nginx服务是否启动：

/ # rc-service nginx status
 * You are attempting to run an openrc service on a
 * system which openrc did not boot.
 * You may be inside a chroot or you may have used
 * another initialization system to boot this system.
 * In this situation, you will get unpredictable results!
 * If you really want to do this, issue the following command:
 * touch /run/openrc/softlevel

所以从上面的输出我们看到我们有两个问题，openrc没有启动，还有一个文件丢失softlevel：

/ # ls -la /run/
total 12
drwxr-xr-x    1 root     root          4096 Jan 16 08:15 .
drwxr-xr-x    1 root     root          4096 Jan 16 08:12 ..
drwxrwxr-x    2 nginx    nginx         4096 Jan 16 08:22 nginx

让我们首先通过输入openrc 来启动我们的系统：

/ # openrc
 * Caching service dependencies ...
Service `hwdrivers' needs non existent service `dev'

/ # ls -la /run/
total 16
drwxr-xr-x    1 root     root          4096 Jan 16 08:29 .
drwxr-xr-x    1 root     root          4096 Jan 16 08:12 ..
drwxrwxr-x    2 nginx    nginx         4096 Jan 16 08:22 nginx
drwxr-xr-x   14 root     root          4096 Jan 16 08:29 openrc

/ # ls -la /run/openrc/
total 64
drwxr-xr-x   14 root     root          4096 Jan 16 08:29 .
drwxr-xr-x    1 root     root          4096 Jan 16 08:29 ..
drwxr-xr-x    2 root     root          4096 Jan 16 08:29 daemons
-rw-r--r--    1 root     root            11 Jan 16 08:29 depconfig
-rw-r--r--    1 root     root          2895 Jan 16 08:29 deptree
drwxr-xr-x    2 root     root          4096 Jan 16 08:29 exclusive
drwxr-xr-x    2 root     root          4096 Jan 16 08:29 failed
drwxr-xr-x    2 root     root          4096 Jan 16 08:29 hotplugged
drwxr-xr-x    2 root     root          4096 Jan 16 08:29 inactive
drwxr-xr-x    2 root     root          4096 Jan 16 08:29 options
drwxr-xr-x    2 root     root          4096 Jan 16 08:29 scheduled
drwxr-xr-x    2 root     root          4096 Jan 16 08:29 started
drwxr-xr-x    2 root     root          4096 Jan 16 08:29 starting
drwxr-xr-x    2 root     root          4096 Jan 16 08:29 stopping
drwxr-xr-x    2 root     root          4096 Jan 16 08:29 tmp
drwxr-xr-x    2 root     root          4096 Jan 16 08:29 wasinactive

现在我们创建丢失的文件：

/ # touch /run/openrc/softlevel

现在我们的rc-service 命令完美运行：

/ # rc-service nginx status
 * status: stopped

让我们启动我们的服务器：

 / # rc-service nginx start
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/blkio/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/cpu/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/cpuacct/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/cpuset/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/devices/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/freezer/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/hugetlb/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/memory/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/net_cls/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/net_prio/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/perf_event/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/pids/tasks: Read-only file system
 * Starting nginx ...          [ ok ]

检查是否启动：

/ # rc-service nginx status
 * status: started

#ANSWER 2

或者你可以简单地调用这两个命令行：

/ # openrc
 * Caching service dependencies ...
Service `hwdrivers' needs non existent service `dev'    [ ok ]

/ # touch /run/openrc/softlevel

现在你可以启动你的 nginx 服务器了 :)

/ # rc-service nginx status
 * status: stopped

/ # rc-service nginx start
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/blkio/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/cpu/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/cpuacct/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/cpuset/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/devices/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/freezer/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/hugetlb/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/memory/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/net_cls/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/net_prio/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/perf_event/tasks: Read-only file system
/lib/rc/sh/openrc-run.sh: line 100: can't create /sys/fs/cgroup/pids/tasks: Read-only file system
 * /run/nginx: creating directory
 * /run/nginx: correcting owner
 * Starting nginx ...         [ ok ]

/ # rc-service nginx status
 * status: started

希望我是清楚的。

Answer 2

一个 Docker 容器通常只运行一个进程。您不需要“启动服务”或“重新启动服务”；一般服务器进程本身就是容器的主进程，如果需要重启服务，就重启整个容器。通常，“服务”类型的命令在 Docker 上下文中缺少一些关键的基础设施，因此无法正常工作。

在您的 Dockerfile 中，您可以将主要命令设置为将 Nginx 作为前台进程启动

# No need for openrc
CMD nginx -g "daemon off;"

然后当你需要更改配置时，构建一个新镜像并重新创建容器

docker build -t my-nginx .
docker stop nginx
docker rm nginx
docker run --name nginx -p 3333:80 -d my-nginx