我使用Docker已经有一段时间了,在处理持久数据时不断发现同样的问题。

我创建Dockerfile并公开一个卷或使用——volumes-from在容器中挂载一个主机文件夹。

主机上的共享卷需要申请哪些权限?

我可以想到两个选择:

So far I've given everyone read/write access, so I can write to the folder from the Docker container. Map the users from host into the container, so I can assign more granular permissions. Not sure this is possible though and haven't found much about it. So far, all I can do is run the container as some user: docker run -i -t -user="myuser" postgres, but this user has a different UID than my host myuser, so permissions do not work. Also, I'm unsure if mapping the users will pose some security risks.

还有其他选择吗?

你们是如何处理这个问题的?


当前回答

基地图片

使用这个图片:https://hub.docker.com/r/reduardo7/docker-host-user

or

重要:这会破坏容器在主机间的可移植性。

1) init.sh

#!/bin/bash

if ! getent passwd $DOCKDEV_USER_NAME > /dev/null
  then
    echo "Creating user $DOCKDEV_USER_NAME:$DOCKDEV_GROUP_NAME"
    groupadd --gid $DOCKDEV_GROUP_ID -r $DOCKDEV_GROUP_NAME
    useradd --system --uid=$DOCKDEV_USER_ID --gid=$DOCKDEV_GROUP_ID \
        --home-dir /home --password $DOCKDEV_USER_NAME $DOCKDEV_USER_NAME
    usermod -a -G sudo $DOCKDEV_USER_NAME
    chown -R $DOCKDEV_USER_NAME:$DOCKDEV_GROUP_NAME /home
  fi

sudo -u $DOCKDEV_USER_NAME bash

2) Dockerfile

FROM ubuntu:latest
# Volumes
    VOLUME ["/home/data"]
# Copy Files
    COPY /home/data/init.sh /home
# Init
    RUN chmod a+x /home/init.sh

3) run.sh

#!/bin/bash

DOCKDEV_VARIABLES=(\
  DOCKDEV_USER_NAME=$USERNAME\
  DOCKDEV_USER_ID=$UID\
  DOCKDEV_GROUP_NAME=$(id -g -n $USERNAME)\
  DOCKDEV_GROUP_ID=$(id -g $USERNAME)\
)

cmd="docker run"

if [ ! -z "${DOCKDEV_VARIABLES}" ]; then
  for v in ${DOCKDEV_VARIABLES[@]}; do
    cmd="${cmd} -e ${v}"
  done
fi

# /home/usr/data contains init.sh
$cmd -v /home/usr/data:/home/data -i -t my-image /home/init.sh

4)使用docker构建

4)跑!

sh run.sh

其他回答

尝试在Dockerfile中添加命令

RUN usermod -u 1000 www-data

Credits转至https://github.com/denderello/symfony-docker-example/issues/2#issuecomment-94387272

好的,这现在被跟踪在docker问题#7198

现在,我用你的第二个选择来处理这个问题:

将用户从主机映射到容器

Dockerfile

#=======
# Users
#=======
# TODO: Idk how to fix hardcoding uid & gid, specifics to docker host machine
RUN (adduser --system --uid=1000 --gid=1000 \
        --home /home/myguestuser --shell /bin/bash myguestuser)

CLI

# DIR_HOST and DIR_GUEST belongs to uid:gid 1000:1000
docker run -d -v ${DIR_HOST}:${DIR_GUEST} elgalu/myservice:latest

我目前更倾向于哈米的回答

In my specific case, I was trying to build my node package with the node docker image so that I wouldn't have to install npm on the deployment server. It worked well until, outside out the container and on the host machine, I tried to move a file into the node_modules directory that the node docker image had created, to which I was denied permissions because it was owned by root. I realized that I could work around this by copying the directory out of the container onto the host machine. Via docker docs...

的UID:GID创建复制到本地计算机的文件 调用docker cp命令的用户。

这是我用来更改docker容器中创建的目录的所有权的bash代码。

NODE_IMAGE=node_builder
docker run -v $(pwd)/build:/build -w="/build" --name $NODE_IMAGE node:6-slim npm i --production
# node_modules is owned by root, so we need to copy it out 
docker cp $NODE_IMAGE:/build/node_modules build/lambda 
# you might have issues trying to remove the directory "node_modules" within the shared volume "build", because it is owned by root, so remove the image and its volumes
docker rm -vf $NODE_IMAGE || true

如果需要,您可以使用第二个docker容器删除该目录。

docker run -v $(pwd)/build:/build -w="/build" --name $RMR_IMAGE node:6-slim rm -r node_modules

更新2016-03-02:从Docker 1.9.0开始,Docker已经命名了卷来取代数据容器。下面的答案,以及我链接的博客文章,在如何思考docker内部的数据方面仍然有价值,但考虑使用命名卷来实现下面描述的模式,而不是数据容器。


我认为解决这个问题的规范方法是使用仅数据容器。使用这种方法,对卷数据的所有访问都是通过使用数据容器中的-volumes-的容器进行的,因此主机uid/gid无关紧要。

For example, one use case given in the documentation is backing up a data volume. To do this another container is used to do the backup via tar, and it too uses -volumes-from in order to mount the volume. So I think the key point to grok is: rather than thinking about how to get access to the data on the host with the proper permissions, think about how to do whatever you need -- backups, browsing, etc. -- via another container. The containers themselves need to use consistent uid/gids, but they don't need to map to anything on the host, thereby remaining portable.

这对我来说也相对较新,但如果您有特定的用例,请随意评论,我将尝试扩展答案。

更新:对于注释中的给定用例,您可能有一个image some/graphite来运行graphite,并有一个image some/graphitedata作为数据容器。因此,忽略端口等,image some/graphitedata的Dockerfile是这样的:

FROM debian:jessie
# add our user and group first to make sure their IDs get assigned consistently, regardless of other deps added later
RUN groupadd -r graphite \
  && useradd -r -g graphite graphite
RUN mkdir -p /data/graphite \
  && chown -R graphite:graphite /data/graphite
VOLUME /data/graphite
USER graphite
CMD ["echo", "Data container for graphite"]

构建并创建数据容器:

docker build -t some/graphitedata Dockerfile
docker run --name graphitedata some/graphitedata

some/graphite Dockerfile也应该得到相同的uid/gid,因此它可能看起来像这样:

FROM debian:jessie
# add our user and group first to make sure their IDs get assigned consistently, regardless of other deps added later
RUN groupadd -r graphite \
  && useradd -r -g graphite graphite
# ... graphite installation ...
VOLUME /data/graphite
USER graphite
CMD ["/bin/graphite"]

它的运行方式如下:

docker run --volumes-from=graphitedata some/graphite

好了,现在我们得到了石墨容器和与正确的用户/组相关联的数据容器(注意,您也可以为数据容器重用some/graphite容器,在运行时覆盖entrypoing/cmd,但将它们作为单独的图像IMO更清楚)。

现在,假设您想要编辑数据文件夹中的内容。因此,与其将卷绑定挂载到主机并在那里编辑它,不如创建一个新容器来完成这项工作。我们叫它some/graphitetools。我们还可以创建适当的用户/组,就像some/graphite图像一样。

FROM debian:jessie
# add our user and group first to make sure their IDs get assigned consistently, regardless of other deps added later
RUN groupadd -r graphite \
  && useradd -r -g graphite graphite
VOLUME /data/graphite
USER graphite
CMD ["/bin/bash"]

你可以通过继承Dockerfile中的一些/graphite或一些/ graphitdata使其成为DRY,或者只是重用现有的一个映像(必要时重写entrypoint/cmd)而不是创建一个新的映像。

现在,你只需运行:

docker run -ti --rm --volumes-from=graphitedata some/graphitetools

然后是vi /data/graphite/whatever。txt。这可以很好地工作,因为所有容器都有相同的石墨用户和匹配的uid/gid。

因为从来没有从主机挂载/data/graphite,所以不关心主机uid/gid如何映射到graphite和graphitetools容器中定义的uid/gid。这些容器现在可以部署到任何主机上,并且它们将继续完美地工作。

这样做的好处是,graphitetools可以有各种有用的实用程序和脚本,现在您还可以以可移植的方式部署它们。

更新2:写完这个答案后,我决定写一篇关于这种方法的更完整的博客文章。我希望这能有所帮助。

UPDATE 3: I corrected this answer and added more specifics. It previously contained some incorrect assumptions about ownership and perms -- the ownership is usually assigned at volume creation time i.e. in the data container, because that is when the volume is created. See this blog. This is not a requirement though -- you can just use the data container as a "reference/handle" and set the ownership/perms in another container via chown in an entrypoint, which ends with gosu to run the command as the correct user. If anyone is interested in this approach, please comment and I can provide links to a sample using this approach.

在大多数情况下,这可能不是最好的方法,但它还没有被提及,所以也许它会帮助到某些人。

绑定挂载主机卷 主机文件夹FOOBAR挂载在容器/卷/FOOBAR中 修改容器的启动脚本,以找到感兴趣的卷的GID $ TARGET_GID=$(stat -c "%g" /volume/FOOBAR) 确保您的用户属于一个具有此GID的组(您可能必须创建一个新组)。对于本例,我将假装我的软件在容器内以nobody用户运行,因此我希望确保没有人属于组id等于TARGET_GID的组

  EXISTS=$(cat /etc/group | grep $TARGET_GID | wc -l)

  # Create new group using target GID and add nobody user
  if [ $EXISTS == "0" ]; then
    groupadd -g $TARGET_GID tempgroup
    usermod -a -G tempgroup nobody
  else
    # GID exists, find group name and add
    GROUP=$(getent group $TARGET_GID | cut -d: -f1)
    usermod -a -G $GROUP nobody
  fi

我喜欢这样做是因为我可以轻松地修改主机卷上的组权限,并且知道这些更新的权限适用于docker容器内部。这种情况无需对我的主机文件夹/文件进行任何权限或所有权修改,这让我很高兴。

我不喜欢这种方法,因为它假定将自己添加到容器内的任意组(碰巧使用您想要的GID)中没有危险。它不能与Dockerfile中的USER子句一起使用(除非该用户具有根权限)。此外,它是一种黑客工作;-)

如果你想要硬核,你显然可以在许多方面扩展它——例如,搜索任何子文件上的所有组,多个卷,等等。