diff --git a/docs/sources/reference/commandline/cli.md b/docs/sources/reference/commandline/cli.md index 6e6ccd69aa..c0fcbff27b 100644 --- a/docs/sources/reference/commandline/cli.md +++ b/docs/sources/reference/commandline/cli.md @@ -523,7 +523,7 @@ Creates a new container. --cap-drop=[] Drop Linux capabilities --cidfile="" Write the container ID to the file --cpuset="" CPUs in which to allow execution (0-3, 0,1) - --device=[] Add a host device to the container (e.g. --device=/dev/sdc:/dev/xvdc) + --device=[] Add a host device to the container (e.g. --device=/dev/sdc:/dev/xvdc:rwm) --dns=[] Set custom DNS servers --dns-search=[] Set custom DNS search domains -e, --env=[] Set environment variables @@ -563,6 +563,8 @@ container at any point. This is useful when you want to set up a container configuration ahead of time so that it is ready to start when you need it. +Please see the [run command](#run) section for more details. + #### Example $ sudo docker create -t -i fedora bash @@ -1221,7 +1223,7 @@ removed before the image is removed. --cidfile="" Write the container ID to the file --cpuset="" CPUs in which to allow execution (0-3, 0,1) -d, --detach=false Detached mode: run the container in the background and print the new container ID - --device=[] Add a host device to the container (e.g. --device=/dev/sdc:/dev/xvdc) + --device=[] Add a host device to the container (e.g. --device=/dev/sdc:/dev/xvdc:rwm) --dns=[] Set custom DNS servers --dns-search=[] Set custom DNS search domains -e, --env=[] Set environment variables @@ -1430,8 +1432,31 @@ option enables that. For example, a specific block storage device or loop device or audio device can be added to an otherwise unprivileged container (without the `--privileged` flag) and have the application directly access it. +By default, the container will be able to `read`, `write` and `mknod` these devices. +This can be overridden using a third `:rwm` set of options to each `--device` +flag: + + +``` + $ sudo docker run --device=/dev/sda:/dev/xvdc --rm -it ubuntu fdisk /dev/xvdc + + Command (m for help): q + $ sudo docker run --device=/dev/sda:/dev/xvdc:r --rm -it ubuntu fdisk /dev/xvdc + You will not be able to write the partition table. + + Command (m for help): q + + $ sudo docker run --device=/dev/sda:/dev/xvdc --rm -it ubuntu fdisk /dev/xvdc + + Command (m for help): q + + $ sudo docker run --device=/dev/sda:/dev/xvdc:m --rm -it ubuntu fdisk /dev/xvdc + fdisk: unable to open /dev/xvdc: Operation not permitted +``` + **Note:** -> `--device` cannot be safely used with ephemeral devices. Block devices that may be removed should not be added to untrusted containers with `--device`. +> `--device` cannot be safely used with ephemeral devices. Block devices that +> may be removed should not be added to untrusted containers with `--device`. **A complete example:** diff --git a/docs/sources/reference/run.md b/docs/sources/reference/run.md index 67007ccff7..2183ee957c 100644 --- a/docs/sources/reference/run.md +++ b/docs/sources/reference/run.md @@ -308,6 +308,26 @@ will be accessible within the container. $ sudo docker run --device=/dev/snd:/dev/snd ... +By default, the container will be able to `read`, `write`, and `mknod` these devices. +This can be overridden using a third `:rwm` set of options to each `--device` flag: + + +``` + $ sudo docker run --device=/dev/sda:/dev/xvdc --rm -it ubuntu fdisk /dev/xvdc + + Command (m for help): q + $ sudo docker run --device=/dev/sda:/dev/xvdc:r --rm -it ubuntu fdisk /dev/xvdc + You will not be able to write the partition table. + + Command (m for help): q + + $ sudo docker run --device=/dev/sda:/dev/xvdc:w --rm -it ubuntu fdisk /dev/xvdc + crash.... + + $ sudo docker run --device=/dev/sda:/dev/xvdc:m --rm -it ubuntu fdisk /dev/xvdc + fdisk: unable to open /dev/xvdc: Operation not permitted +``` + In addition to `--privileged`, the operator can have fine grain control over the capabilities using `--cap-add` and `--cap-drop`. By default, Docker has a default list of capabilities that are kept. Both flags support the value `all`, so if the