Bash 如何在Ubuntu Docker容器中启动cron plus Shell脚本

我试图在Ubuntu20.10（Groovy Gorilla）Docker容器中自动启动cron，但迄今为止没有成功

从前面的搜索（）中，我发现了一个使用Dockerfile启动cron的方法，如下所示：

# Install and enable cron
RUN apt-get install systemd -y
RUN apt-get install cron -y
RUN systemctl enable cron

# Copy cron file to the cron.d directory
COPY cronfile /etc/cron.d/cronfile

# Give execution rights on the cron job
RUN chmod 0644 /etc/cron.d/cronfile

# Apply cron job
RUN crontab /etc/cron.d/cronfile

# Create the log file to be able to run tail
RUN touch /var/log/cron.log
CMD cron && tail -f /var/log/cron.log

但是，我的服务器设置无法实现这一点。稍后，我在Dockerfile中还有另一个CMD（类似于）：

当然，只会运行第二个CMD。我已尝试组合多个命令：

CMD cron && tail -f /var/log/cron.log && /usr/sbin/run-lamp.sh

但这不会运行run-lamp.sh。我还尝试将命令放在run-lamp.sh中，但没有任何结果导致cron启动。话虽如此，通过在容器中打开一个shell并输入以下内容，手动启动cron非常容易：

# cron
# crontab /etc/cron.d/cronfile

我愿意听取建议

我正在使用的所有文件都可以在此处找到：

https://github.com/Downes/gRSShopper

特别是： Dockerfile：

https://github.com/Downes/gRSShopper/blob/master/Dockerfile

run-lamp.sh：

https://github.com/Downes/gRSShopper/blob/master/run-lamp.sh

cronfile:

https://github.com/Downes/gRSShopper/blob/master/cronfile

---

提前感谢。

首先，你不需要那种

尾部-f/var/log/cron.log

，它在容器中是无用的

其次，

tail-f

被设计为仅在收到信号时停止，而您从未发出信号，因此它不会停止，因此下一个命令

run lamp.sh

将不会运行

这是一个最小的复制器：

entrypoint.sh

：

#!/bin/bash

touch /tmp/x
sleep 120

cronfile

：

*   *   *   *   *   touch /tmp/y
# An empty line is required at the end of this file for a valid cron file.

FROM ubuntu:20.10

RUN apt-get update
RUN apt-get install systemd -y
RUN apt-get install cron -y
RUN systemctl enable cron

# Copy cron file to the cron.d directory
COPY cronfile /etc/cron.d/cronfile

# Give execution rights on the cron job
RUN chmod 0644 /etc/cron.d/cronfile

# Apply cron job
RUN crontab /etc/cron.d/cronfile

# Create the log file to be able to run tail
RUN touch /var/log/cron.log
CMD cron && tail -f /var/log/cron.log

COPY entrypoint.sh /entrypoint.sh
CMD /entrypoint.sh

FROM ubuntu:20.10

RUN apt-get update
RUN apt-get install systemd -y
RUN apt-get install cron -y
RUN systemctl enable cron

# Copy cron file to the cron.d directory
COPY cronfile /etc/cron.d/cronfile

# Give execution rights on the cron job
RUN chmod 0644 /etc/cron.d/cronfile

# Apply cron job
RUN crontab /etc/cron.d/cronfile

# Create the log file to be able to run tail
RUN touch /var/log/cron.log

COPY entrypoint.sh /entrypoint.sh
# Run everything in parallel with '&', even the useless tail command
CMD /entrypoint.sh & cron & tail -f /var/log/cron.log

Dockerfile

：

*   *   *   *   *   touch /tmp/y
# An empty line is required at the end of this file for a valid cron file.

FROM ubuntu:20.10

RUN apt-get update
RUN apt-get install systemd -y
RUN apt-get install cron -y
RUN systemctl enable cron

# Copy cron file to the cron.d directory
COPY cronfile /etc/cron.d/cronfile

# Give execution rights on the cron job
RUN chmod 0644 /etc/cron.d/cronfile

# Apply cron job
RUN crontab /etc/cron.d/cronfile

# Create the log file to be able to run tail
RUN touch /var/log/cron.log
CMD cron && tail -f /var/log/cron.log

COPY entrypoint.sh /entrypoint.sh
CMD /entrypoint.sh

FROM ubuntu:20.10

RUN apt-get update
RUN apt-get install systemd -y
RUN apt-get install cron -y
RUN systemctl enable cron

# Copy cron file to the cron.d directory
COPY cronfile /etc/cron.d/cronfile

# Give execution rights on the cron job
RUN chmod 0644 /etc/cron.d/cronfile

# Apply cron job
RUN crontab /etc/cron.d/cronfile

# Create the log file to be able to run tail
RUN touch /var/log/cron.log

COPY entrypoint.sh /entrypoint.sh
# Run everything in parallel with '&', even the useless tail command
CMD /entrypoint.sh & cron & tail -f /var/log/cron.log

测试命令：

docker build -t lamp . \
    && docker rm -f lamp \
    && docker run -d --name lamp lamp \
    && echo waiting for cron... \
    && sleep 61 \
    && docker exec lamp ls /tmp \
    && docker exec lamp sh -c "ps -e | grep cron || echo no cron"

结果:

Sending build context to Docker daemon  71.17kB
Step 1/12 : FROM ubuntu:20.10
...
Successfully tagged lamp:latest
lamp
0fbe19e0583b178543ccf1d1108f72b7f3f6dffb664122621bc67d5939b66672
waiting for cron...
x
no cron

Sending build context to Docker daemon  87.55kB
Step 1/11 : FROM ubuntu:20.10
...
Successfully tagged lamp:latest
lamp
99dca45fe135326ca96ea90fe21ff7ae23689a56fab5cf0c2ccd8252bc4be84a
waiting for cron...
x
y
     10 ?        00:00:00 cron

但是，使用此

Dockerfile

：

*   *   *   *   *   touch /tmp/y
# An empty line is required at the end of this file for a valid cron file.

FROM ubuntu:20.10

RUN apt-get update
RUN apt-get install systemd -y
RUN apt-get install cron -y
RUN systemctl enable cron

# Copy cron file to the cron.d directory
COPY cronfile /etc/cron.d/cronfile

# Give execution rights on the cron job
RUN chmod 0644 /etc/cron.d/cronfile

# Apply cron job
RUN crontab /etc/cron.d/cronfile

# Create the log file to be able to run tail
RUN touch /var/log/cron.log
CMD cron && tail -f /var/log/cron.log

COPY entrypoint.sh /entrypoint.sh
CMD /entrypoint.sh

FROM ubuntu:20.10

RUN apt-get update
RUN apt-get install systemd -y
RUN apt-get install cron -y
RUN systemctl enable cron

# Copy cron file to the cron.d directory
COPY cronfile /etc/cron.d/cronfile

# Give execution rights on the cron job
RUN chmod 0644 /etc/cron.d/cronfile

# Apply cron job
RUN crontab /etc/cron.d/cronfile

# Create the log file to be able to run tail
RUN touch /var/log/cron.log

COPY entrypoint.sh /entrypoint.sh
# Run everything in parallel with '&', even the useless tail command
CMD /entrypoint.sh & cron & tail -f /var/log/cron.log

结果:

Sending build context to Docker daemon  71.17kB
Step 1/12 : FROM ubuntu:20.10
...
Successfully tagged lamp:latest
lamp
0fbe19e0583b178543ccf1d1108f72b7f3f6dffb664122621bc67d5939b66672
waiting for cron...
x
no cron

Sending build context to Docker daemon  87.55kB
Step 1/11 : FROM ubuntu:20.10
...
Successfully tagged lamp:latest
lamp
99dca45fe135326ca96ea90fe21ff7ae23689a56fab5cf0c2ccd8252bc4be84a
waiting for cron...
x
y
     10 ?        00:00:00 cron

---

通常，您希望每个容器只运行一个进程，在本例中，这意味着运行一个单独的容器，只运行一个前台cron守护进程。这个设置对你有用吗？这就是我现在正在调查的。