I'm trying to run a Docker container with access to a serial port on the host.
Here is what I did:
I used a Mac
Installed drivers on the host
(http://www.prolific.com.tw/US/ShowProduct.aspx?p_id=229&pcid=41)
Plugged in the device
Ran ls /dev/t* that returned
/dev/tty.usbserial - so it worked
Ran the container, docker run -it --privileged -v /dev:/dev
node:4.4.0 /bin/bash, and then ls /dev/t* inside the container which didn't return the /dev/tty.usbserial device...
I played a lot with different variations of parameters, but I haven't found the working one :)
Also the --device flag is not suitable for me since the device might be reconnected and the name could differ from /dev/tty.usbserial.
You can check if the script described in "Notification of new USB devices in docker container" (from Guido Diepen -- gdiepen) can help.
He too runs his container with the --privileged argument to allow it to access the devices. And he mounts the host directory /dev/bus/usb to the /dev/bus/usb directory within the container with the argument -v /dev/bus/usb:/dev/bus/usb when starting said container.
The script uses both inotifywait and lsusb to wait for devices to be (un)plugged and check if it was the device we are interested in.
The inotifywait will keep on listening to inodes create/delete events under the dev/bus/usb directory and will execute commands whenever an inode corresponding to a relevant device has been just created.
See also, once you have detected an plugged USB device, How to get Bus and Device relationship for a /dev/ttyUSB (not related to Docker, but still relevant).
As pointed by #pgayvallet on GitHub:
As the daemon runs inside a VM in Docker Desktop, it is not possible to actually share a mac host device with the container inside the VM, and this will most definitely never be possible.
Related
my goal is to run Windows container with a desktop app (EXE) installed inside, having its own GUI (CAD).
It's not a problem to build the container, installing silently the app, however I cannot realize how its output (GUI) would be redirect/catch up in Windows docker host to interact with it.
Digging web I found DISPLAY envvar setting for Linux container, but nothing for Windows' one.
I cannot believe it's impossible to get graphic output from Windows Container.
Please help,
Thanks in advance!
Yes, unfortunately docker containers are not designed for GUI using. It possible if only your app is accessible through web browser
you need XServer, running on windows host machine
for example, install VcSrv https://sourceforge.net/projects/vcxsrv/
run it, then see ipconfig in console
find vEthernet ipv4
my ipconfig
use it when run docker container, for example try
docker run --rm -it --net=host -e DISPLAY=172.22.96.1:0 stefanscherer/xeyes
in env DISPLAY set your ipv4 from vEthernet in ipconfig
I am trying to use named pipes for inter-process communication inside a docker container but am getting "not found" errors when trying to read/write. Does docker for windows support named pipes? The software's been released and I know it works fine in VMs. I just can't find anything saying yes or no that containers on windows support named pipes.
I've got an IIS application with a named pipe binding installed inside the container along with a client application also inside the container trying to communicate via net.pipe://localhost. My run command looks like this
docker run -it -m 2GB -p 80:80 --network External company/appserver
The error message is
The pipe endpoint 'net.pipe://localhost/WCFSvc/WCF.svc' could not be
found on your local machine
You can mount named pipes into Docker containers, but this only works on Windows Server 1709 and later. I put an example in my blog post: https://blog.docker.com/2017/09/docker-windows-server-1709/
docker run -d -p 8080:8080 -v \\.\pipe\docker_engine:\\.\pipe\docker_engine friism/jenkins
I'm using Docker 1.13.1 for Mac. The Docker client allows you to change the amount of memory provided to Docker using a simple slider interface.
How can I set this value via docker's command line utility?
For added clarity, this is not per container memory, this is the value of "Total Memory" that's returned when you run docker info.
Thank you
With docker (at least version 18.03.1) the settings for the VM are maintained in a special file located at:
/Users/<username>/Library/Group\ Containers/group.com.docker/settings.json
If you close docker you can edit it directly from the command line using sed, for example the command below will replace the 2 GB limit with a 10GB limit, and create a backup file of the original settings at settings.json.bak
sed -i .bak 's/2048/10240/g' /Users/`id -un`/Library/Group\ Containers/group.com.docker/settings.json
When docker restarts, it will now have 10 GB.
On a Mac, Docker actually runs as a Hyperkit virtual machine. The docker command line utility just interfaces with the docker daemon process running inside that virtual machine.
If you run ps auxwww | grep hyperkit on your Mac, you'll see the hyperkit process running with the amount of memory passed as an argument. This is controlled by the Docker Mac client, and I imagine the saved value is stored in a .plist file somewhere.
In order to modify that on the command line, you'd need to find where the Docker Mac client stores the data, modify it, and restart the hyperkit process.
I'm working on wrapping some scientific software by docker image using boot2docker on Mac OS X. And that software (https://github.com/voutcn/megahit.git) is using named pipes (in python code, but it's not important) to wire different parts (written in C) to each other. I mount temporary folder from host Mac OS X machine to provide scratch area in docker container (because temporary output of software could be huge) with something like this:
docker run -v /external/folder:/tmp/scratch <image> <args>
It gives me this mount line inside container:
none on /tmp/scratch type vboxsf (rw,nodev,relatime)
And inside this mounted folder named pipe creation fails when it runs inside container. It's not even related to python, C or any particular language. I double checked with linux command mkfifo pipe1 in this folder with an error:
mkfifo: cannot create fifo 'pipe1': Operation not permitted
It works well for any internal not mounted folder inside container though. Why does it happen and how could it be fixed?
PS: Here is what I do to easily reproduce the problem.
1) Mac OS X with boot2docker
2) Dockerfile is:
FROM ubuntu:14.04
#WORKDIR /tmp <- this one would work
WORKDIR /tmp/scratch
ENTRYPOINT [ "mkfifo" ]
CMD [ "pipe1" ]
3) Image building:
docker build --rm -t mine/namedpipes:latest .
4) Running (being in external host folder to be mounted):
docker run -v $(pwd):/tmp/scratch mine/namedpipes:latest
Upgrade to a recent version of Docker for Mac, and your problem will likely be solved: https://docs.docker.com/docker-for-mac/release-notes/#beta-2-release-2016-03-08-1102-beta2
The issue is that FIFOs are actually kernel objects you access using the filesystem, and so you would need extra work to support cross-kernel FIFOs (or unix domain sockets) - a fifo is either valid inside the Linux guest running the docker daemon or in the OS X host, not in both, and it makes sense that you can't create an OS X fifo from inside the linux box. It would be sort of like trying to create a fifo on a network drive, it doesn't make sense as a local IPC mechanism.
Current support for special files is detailed in https://docs.docker.com/docker-for-mac/osxfs/#file-types
The issue for cross-hypervisor support is located at https://github.com/docker/for-mac/issues/483
I installed boot2docker as explained on the docker website. Here are some command runs to show that I have things installed correctly:
$$:~ kv$ boot2docker start
Waiting for VM and Docker daemon to start...
...................ooo
Started.
Writing /Users/kvantum/.boot2docker/certs/boot2docker-vm/ca.pem
Writing /Users/kvantum/.boot2docker/certs/boot2docker-vm/cert.pem
Writing /Users/kvantum/.boot2docker/certs/boot2docker-vm/key.pem
Your environment variables are already set correctly.
$$:~ kv$ docker images
REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
ubuntu 14.04 b39b81afc8ca 11 days ago 188.3 MB
hello-world latest e45a5af57b00 3 weeks ago 910 B
After this, I ran the following command:
docker run -t -i ubuntu:14.04 /bin/bash
Inside the container, I installed zeromq, and started a zeromq server on port 5555 using tcp.
My questions are following:
If I exit out of the container, will it save all the work I do inside it?
I have no idea how to connect to the server running on port 5555. I read something about exposing a port, but I am not sure how to go about doing that. I did an ifconfig inside the container, and tried to connect to the server from the host like this:
$$:~ kv$ ./zmq_client tcp://container_ip:5555
This did not work. Can someone please lists the steps I need to take in order to connect to the server running within the container.
For completion sake, I am providing the list of my environment variables:
TERM_PROGRAM=Apple_Terminal
TERM=xterm-256color
SHELL=/bin/bash
TMPDIR=/var/folders/km/5kbpdx4s7cg4rmyc6d5q9l9r0000gq/T/
DOCKER_HOST=tcp://192.168.109.103:2376
Apple_PubSub_Socket_Render=/tmp/launch-1tWMHJ/Render
TERM_PROGRAM_VERSION=326
OLDPWD=/Users
TERM_SESSION_ID=262CBC8B-0A74-4B70-9F28-D9FA51FF713C
USER=kv
SSH_AUTH_SOCK=/tmp/launch-ZTWNGL/Listeners
__CF_USER_TEXT_ENCODING=0x1F7:0:0
DOCKER_TLS_VERIFY=1
__CHECKFIX1436934=1
PATH=/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/opt/X11/bin
PWD=/Users/kv
DOCKER_CERT_PATH=/Users/kv/.boot2docker/certs/boot2docker-vm
HOME=/Users/kv
SHLVL=1
LOGNAME=kv
LC_CTYPE=UTF-8
DISPLAY=/tmp/launch-rco9zt/org.macosforge.xquartz:0
_=/usr/bin/env
One last question I have is about code performance. So within my Mac OS X, I have a docker container running (which runs Ubuntu). If I run the application, like a zeromq based server inside the container, will it not be slower as compared to running it on Mac OS X directly. Please explain the benefits of using docker in such a scenario..
You should really do some more reading and research before turning to SO, then ask about anything you can't figure out. But:
No. If the container is "exited" you can restart it and your files will still be there, but once it is removed your files are gone. You can use docker commit to save them to an image, but the best bet is to use a Dockerfile.
docker run -p 5000:8000 image will expose port 8000 in the container as port 5000 on the host.
Yes, it will be slower due to the boot2docker VM. It would not be slower if you were running on a Linux host. The advantage is that zeromq is now running in an isolated container with all its dependencies.