这里有很多答案，但没有一个符合我的需要。我想知道提问者第一个问题的确切答案。如何知道hub.docker.com上的图像何时更新?

下面的脚本可以每天运行。在第一次运行时，它从HUB注册中心获得标记的基线和更新日期，并将它们保存在本地。从那时起，每次运行它都会检查注册表中的新标记和更新日期。因为每当有新图像存在时，它都会改变，所以它会告诉我们基本图像是否发生了变化。以下是剧本:

#!/bin/bash

DATAPATH='/data/docker/updater/data'

if [ ! -d "${DATAPATH}" ]; then
        mkdir "${DATAPATH}";
fi
IMAGES=$(docker ps --format "{{.Image}}")
for IMAGE in $IMAGES; do
        ORIGIMAGE=${IMAGE}
        if [[ "$IMAGE" != *\/* ]]; then
                IMAGE=library/${IMAGE}
        fi
        IMAGE=${IMAGE%%:*}
        echo "Checking ${IMAGE}"
        PARSED=${IMAGE//\//.}
        if [ ! -f "${DATAPATH}/${PARSED}" ]; then
                # File doesn't exist yet, make baseline
                echo "Setting baseline for ${IMAGE}"
                curl -s "https://registry.hub.docker.com/v2/repositories/${IMAGE}/tags/" > "${DATAPATH}/${PARSED}"
        else
                # File does exist, do a compare
                NEW=$(curl -s "https://registry.hub.docker.com/v2/repositories/${IMAGE}/tags/")
                OLD=$(cat "${DATAPATH}/${PARSED}")
                if [[ "${VAR1}" == "${VAR2}" ]]; then
                        echo "Image ${IMAGE} is up to date";
                else
                        echo ${NEW} > "${DATAPATH}/${PARSED}"
                        echo "Image ${IMAGE} needs to be updated";
                        H=`hostname`
                        ssh -i /data/keys/<KEYFILE> <USER>@<REMOTEHOST>.com "{ echo \"MAIL FROM: root@${H}\"; echo \"RCPT TO: <USER>@<EMAILHOST>.com\"; echo \"DATA\"; echo \"Subject: ${H} - ${IMAGE} needs update\"; echo \"\"; echo -e \"\n${IMAGE} needs update.\n\ndocker pull ${ORIGIMAGE}\"; echo \"\"; echo \".\"; echo \"quit\"; sleep 1; } | telnet <SMTPHOST> 25"
                fi

        fi
done;

您可能需要更改顶部的DATAPATH变量，并更改末尾的电子邮件通知命令以满足您的需要。对我来说，我把它SSH到我的SMTP所在的另一个网络上的服务器上。但是您也可以轻松地使用邮件命令。

现在，您还需要检查容器本身中是否有更新的包。这实际上可能比在容器工作后“拉”更有效。以下是实现这一目标的脚本:

#!/bin/bash


function needsUpdates() {
        RESULT=$(docker exec ${1} bash -c ' \
                if [[ -f /etc/apt/sources.list ]]; then \
                grep security /etc/apt/sources.list > /tmp/security.list; \
                apt-get update > /dev/null; \
                apt-get upgrade -oDir::Etc::Sourcelist=/tmp/security.list -s; \
                fi; \
                ')
        RESULT=$(echo $RESULT)
        GOODRESULT="Reading package lists... Building dependency tree... Reading state information... Calculating upgrade... 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded."
        if [[ "${RESULT}" != "" ]] && [[ "${RESULT}" != "${GOODRESULT}" ]]; then
                return 0
        else
                return 1
        fi
}

function sendEmail() {
        echo "Container ${1} needs security updates";
        H=`hostname`
        ssh -i /data/keys/<KEYFILE> <USRER>@<REMOTEHOST>.com "{ echo \"MAIL FROM: root@${H}\"; echo \"RCPT TO: <USER>@<EMAILHOST>.com\"; echo \"DATA\"; echo \"Subject: ${H} - ${1} container needs security update\"; echo \"\"; echo -e \"\n${1} container needs update.\n\n\"; echo -e \"docker exec ${1} bash -c 'grep security /etc/apt/sources.list > /tmp/security.list; apt-get update > /dev/null; apt-get upgrade -oDir::Etc::Sourcelist=/tmp/security.list -s'\n\n\"; echo \"Remove the -s to run the update\"; echo \"\"; echo \".\"; echo \"quit\"; sleep 1; } | telnet <SMTPHOST> 25"
}

CONTAINERS=$(docker ps --format "{{.Names}}")
for CONTAINER in $CONTAINERS; do
        echo "Checking ${CONTAINER}"
        if needsUpdates $CONTAINER; then
                sendEmail $CONTAINER
        fi
done

一种“docker方式”是使用docker hub自动构建。当上游容器被重建时，Repository Links特性将重建你的容器，Webhooks特性将向你发送通知。

看起来webhooks仅限于HTTP POST调用。您需要设置一个服务来捕获它们，或者可能使用其中一个POST发送电子邮件服务。

我还没有深入研究，但是新的Docker通用控制平面可能有一个检测更新容器和重新部署的功能。

更新:使用Dependabot - https://dependabot.com/docker/

BLUF:找到正确的插入点来监视容器的更改是一个挑战。如果DockerHub能解决这个问题，那就太好了。(存储库链接已经提到过，但注意在DockerHub上设置它们时-“每当在DockerHub上更新基本映像时，都会在此存储库中触发一个构建。只适用于非官方图片。”)

当我自己尝试解决这个问题时，我看到了几个webhook的建议，所以我想详细说明我使用过的几个解决方案。

Use microbadger.com to track changes in a container and use it's notification webhook feature to trigger an action. I set this up with zapier.com (but you can use any customizable webhook service) to create a new issue in my github repository that uses Alpine as a base image. Pros: You can review the changes reported by microbadger in github before taking action. Cons: Microbadger doesn't let you track a specific tag. Looks like it only tracks 'latest'. Track the RSS feed for git commits to an upstream container. ex. https://github.com/gliderlabs/docker-alpine/commits/rootfs/library-3.8/x86_64. I used zapier.com to monitor this feed and to trigger an automatic build of my container in Travis-CI anytime something is committed. This is a little extreme but you can change the trigger to do other things like open an issue in your git repository for manual intervention. Pros: Closer to an automated pipline. The Travis-CI build just checks to see if your container has issues with whatever was committed to the base image repository. It's up to you if your CI service takes any further action. Cons: Tracking the commit feed isn't perfect. Lots of things get committed to the repository that don't affect the build of the base image. Doesn't take in to account any issues with frequency/number of commits and any API throttling.

我也遇到过同样的问题，我认为可以通过cron作业每天调用无人值机升级来简单解决。

我的意图是将其作为一种自动和快速的解决方案，以确保生产容器是安全和更新的，因为更新映像和部署具有最新安全更新的新docker映像需要花费一些时间。

也可以使用Github钩子自动化映像的构建和部署

我已经创建了一个基本的docker映像，每天自动检查和安装安全更新(可以通过docker run itech/docker- unattentedupgrade直接运行)。

我还发现了另一种检查容器是否需要更新的方法。

我的完整实现:

Dockerfile

FROM ubuntu:14.04   

RUN apt-get update \
&& apt-get install -y supervisor unattended-upgrades \
&& rm -rf /var/lib/apt/lists/*

COPY install /install
RUN chmod 755 install
RUN /install

COPY start /start
RUN chmod 755 /start

辅助脚本

安装

#!/bin/bash
set -e

cat > /etc/supervisor/conf.d/cron.conf <<EOF
[program:cron]
priority=20
directory=/tmp
command=/usr/sbin/cron -f
user=root
autostart=true
autorestart=true
stdout_logfile=/var/log/supervisor/%(program_name)s.log
stderr_logfile=/var/log/supervisor/%(program_name)s.log
EOF

rm -rf /var/lib/apt/lists/*

ENTRYPOINT ["/start"]

开始

#!/bin/bash

set -e

echo "Adding crontab for unattended-upgrade ..."
echo "0 0 * * * root /usr/bin/unattended-upgrade" >> /etc/crontab

# can also use @daily syntax or use /etc/cron.daily

echo "Starting supervisord ..."
exec /usr/bin/supervisord -n -c /etc/supervisor/supervisord.conf

Edit

我开发了一个小工具docker-run，它作为docker容器运行，可以用来更新所有或选定的运行容器中的包，它也可以用来运行任何任意命令。

可以使用以下命令轻松测试:

Docker run——rm -v /var/run/ Docker .sock:/tmp/ Docker .sockSock itech/docker-run exec

默认情况下，它将在所有运行的容器中执行date命令并显示结果。如果你传递update而不是exec，它将在所有运行的容器中执行apt-get update和apt-get upgrade -y

你不会知道你的集装箱在后面没有运行码头拉。然后，您需要重新构建或重组您的映像。

docker pull image:tag
docker-compose -f docker-compose.yml -f production.yml up -d --build

这些命令可以与完成升级所需的任何其他东西一起放在脚本中，尽管一个合适的容器不需要任何额外的东西。

下面是一种自动更新docker容器的最简单方法

通过$ crontab -e放置作业:

0 * * * * sh ~/.docker/cron.sh

创建目录~/。Docker与文件cron.sh:

#!/bin/sh
if grep -Fqe "Image is up to date" << EOF
`docker pull ubuntu:latest`
EOF
then
    echo "no update, just do cleaning"
    docker system prune --force
else
    echo "newest exist, recompose!"
    cd /path/to/your/compose/file
    docker-compose down --volumes
    docker-compose up -d
fi