I use jack to route audio between multiple sound cards in my pc.
To record the audio i use a very convenient FFmpeg command which creates a writable jack client:
ffmpeg -f jack -i <client_name> -strict -2 -y <output_file_name>.
so far this works very well.
The problem starts here:
I also have an nginx docker which records my data and makes it available for streaming. when trying to use the same command inside the docker i get the following error:"Unable to register as a JACK client".
I started to look in to the FFmpeg code and found out that the FFmpeg command calls the jack_client_open command from the jack API, which fails.
Seems like there is some kind of a problem in the connection between the FFmpeg request from inside the docker to the jackd server running on the host.
Is there a simple way to create a connection between the two [exposing ports]?
(I saw some solutions like netjack2, but before creating a more complex server-client architecture i'd like to find a more elegant solution).
Thanks for the help!
I've just got this working, and I required the following in my docker run commands:
--volume=/dev/shm:/dev/shm:rw
--user=1000
So that the container is running a user which can access files in /dev/shm from a jackd spawned from my host user account. This wouldn't be required if your jackd and the container are both running as user root.
You can confirm its working by running jack_simple_client in the container, you should get a beep.
Related
I'm trying to create a Docker image that works with a speaker and microphone.
I've got it working with Ubuntu as host using:
docker run -it --device /dev/snd:/dev/snd <docker_container>
I'd also like to be able to use the Docker image on windows and mac hosts, but can't find the equivalent of /dev/snd to make use of the host's speaker/microphone.
Any help appreciated
I was able to get playback on Windows using pulseaudio.exe.
1] Download pulseaudio for windows: https://www.freedesktop.org/wiki/Software/PulseAudio/Ports/Windows/Support/
2] Uncompress and change the config files.
2a] Add the following line to your $INSTALL_DIR/etc/pulse/default.pa:
load-module module-native-protocol-tcp listen=0.0.0.0 auth-anonymous=1
This is an insecure setting: there are IP-based ones that are more secure but there's some Docker sorcery involved in leveraging them I think. While the process is running anyone on your network will be able to push sound to this port; this risk will be acceptable for most users.
2b] Change $INSTALL_DIR/etc/pulse//etc/pulse/daemon.conf line to read:
exit-idle-time = -1
This will keep the daemon open after the last client disconnects.
3) Run pulseaudio.exe. You can run it as
start "" /B "pulseaudio.exe"
to background it but its tricker to kill than just a simple execution.
4) In the container's shell:
export PULSE_SERVER=tcp:127.0.0.1
One of the articles I sourced this from (https://token2shell.com/howto/x410/enabling-sound-in-wsl-ubuntu-let-it-sing/) suggests recording may be blocked in Windows 10.
Summary
So I'm trying to figure out a way to use docker to be able to spin up testing environments for customers rather easily. Basically, I've got a customized piece of software that want to install to a Windows docker container (microsoft/windowsservercore), and I need to be able to access the program folder for that software (C:\Program Files\SOFTWARE_NAME) as it has some logs, imports/exports, and other miscellaneous configuration files. The installation part was easy, and I figured that after a few hours of messing around with docker and learning how it works, but transferring files in a simple manner is proving far more difficult than I would expect. I'm well aware of the docker cp command, but I'd like something that allows for the files to be viewed in a file browser to allow testers to quickly/easily view log/configuration files from the container.
Background (what I've tried):
I've spent 20+ hours monkeying around with running an SSH server on the docker container, so I could just ssh in and move files back and forth, but I've had no luck. I've spent most of my time trying to configure OpenSSH, and I can get it installed, but there appears to be something wrong with the default configuration file provided with my installation, as I can't get it up and running unless I start it manually via command line by running sshd -d. Strangely, this runs just fine, but it isn't really a viable solution as it is running in debug mode and shuts down as soon as the connection is closed. I can provide more detail on what I've tested with this, but it seems like it might be a dead end (even though I feel like this should be extremely simple). I've followed every guide I can find (though half are specific to linux containers), and haven't gotten any of them to work, and half the posts I've found just say "why would you want to use ssh when you can just use the built in docker commands". I want to use ssh because it's simpler from an end user's perspective, and I'd rather tell a tester to ssh to a particular IP than make them interact with docker via the command line.
EDIT: Using OpenSSH
Starting server using net start sshd, which reports it starting successfully, however, the service stops immediately if I haven't generated at least an RSA or DSA key using:
ssh-keygen.exe -f "C:\\Program Files\\OpenSSH-Win64/./ssh_host_rsa_key" -t rsa
And modifying the permissions using:
icacls "C:\Program Files\OpenSSH-Win64/" /grant sshd:(OI)(CI)F /T
and
icacls "C:\Program Files\OpenSSH-Win64/" /grant ContainerAdministrator:(OI)(CI)F /T
Again, I'm using the default supplied sshd_config file, but I've tried just about every adjustment of those settings I can find and none of them help.
I also attempted to setup Volumes to do this, but because the installation of our software is done at compile time in docker, the folder that I want to map as a volume is already populated with files, which seems to make docker fail when I try to start the container with the volume attached. This section of documentation seems to say this should be possible, but I can't get it to work. Keep getting errors when I try to start the container saying "the directory is not empty".
EDIT: Command used:
docker run -it -d -p 9999:9092 --mount source=my_volume,destination=C:/temp my_container
Running this on a ProxMox VM.
At this point, I'm running out of ideas, and something that I feel like should be incredibly simple is taking me far too many hours to figure out. It particularly frustrates me that I see so many blog posts saying "Just use the built in docker cp command!" when that is honestly a pretty bad solution when you're going to be browsing lots of files and viewing/editing them. I really need a method that allows the files to be viewed in a file browser/notepad++.
Is there something obvious here that I'm missing? How is this so difficult? Any help is appreciated.
So after a fair bit more troubleshooting, I was unable to get the docker volume to initialize on an already populated folder, even though the documentation suggests it should be possible.
So, I instead decided to try to start the container with the volume linked to an empty folder, and then start the installation script for the program after the container is running, so the folder populates after the volume is already linked. This worked perfectly! There's a bit of weirdness if you leave the files in the volume and then try to restart the container, as it will overwrite most of the files, but things like logs and files not created by the installer will remain, so we'll have to figure out some process for managing that, but it works just like I need it to, and then I can use windows sharing to access that volume folder from anywhere on the network.
Here's how I got it working, it's actually very simple.
So in my dockerfile, I added a batch script that unzips the installation DVD that is copied to the container, and runs the installer after extracting. I then used the CMD option to run this on container start:
Dockerfile
FROM microsoft/windowsservercore
ADD DVD.zip C:\\resources\\DVD.zip
ADD config.bat C:\\resources\\config.bat
CMD "C:\resources\config.bat" && cmd
Then I build the container without anything special:
docker build -t my_container:latest .
And run it with the attachment to the volume:
docker run -it -d -p 9999:9092 --mount source=my_volume,destination="C:/Program Files (x86)/{PROGRAM NAME}" my_container
And that's it. Unfortunately, the container takes a little longer to start (it does build faster though, for what that's worth, as it isn't running the installer in the build), and the program isn't installed/running for another 5 minutes or so after the container does start, but it works!
I can provide more details if anyone needs them, but most of the rest is implementation specific and fairly straightforward.
Try this with Docker composer. Unfortunately, I cannot test it as I'm using a Mac it's not a "supported platform" (way to go Windows). See if that works, if not try volume line like this instead - ./my_volume:C:/tmp/
Dockerfile
FROM microsoft/windowsservercore
# need to ecape \
WORKDIR C:\\tmp\\
# Add the program from host machine to container
ADD ["<source>", "C:\tmp"]
# Normally used with web servers
# EXPOSE 80
# Running the program
CMD ["C:\tmp\program.exe", "any-parameter"]
Docker Composer
Should ideally be in the parent folder.
version: "3"
services:
windows:
build: ./folder-of-Dockerfile
volume:
- type: bind
source: ./my_volume
target: C:/tmp/
ports:
- 9999:9092
Folder structure
|---docker-composer.yml
|
|---folder-of-Dockerfile
|
|---Dockerfile
Just run docker-composer up to build and start the container. Use -d for detach mode, should only use once you know its working properly.
Useful link Manage Windows Dockerfile
I'm using various docker containers which, under the covers are built on Debian sid. These images lack /dev/snd and /dev/snd/seq, which pretty much makes sense since they have no hardware audio card.
Several pieces of software I'm using to generate MIDI files require these sequencer devices to be present. They're not necessarily used to send out audio, but the code itself dies in init if the sound devices do not exist. To be clear, I don't need to generate an audio signal within docker, rather I just need these to exist to make other software happy.
So far, what I've tried is endlessly installing various alsa packages (alsa-utils, alsa-oss, and others) and trying to modprobe my way out of this, all with no luck.
Within a docker container, what needs to happen to have valid audio devices even if dummy?
I've had success getting sound through Docker (not the same problem, I know) by adding the devices whe running the container.
docker run -it --device /dev/snd myimage
The permissions can get challenging very quickly, you might want to try initially using --device /dev/snd along with --privileged and then dial back privileges little by little once it works.
I'm trying to create a Docker container based on CentOS 7 that will host R, shiny-server, and rstudio-server, but to I need to have systemd in order for the services to start. I can use the systemd enabled centos image as a basis, but then I need to run the container in privileged mode and allow access to /sys/fs/cgroup on the host. I might be able to tolerate the less secure situation, but then I'm not able to share the container with users running Docker on Windows or Mac.
I found this question but it is 2 years old and doesn't seem to have any resolution.
Any tips or alternatives are appreciated.
UPDATE: SUCCESS!
Here's what I found: For shiny-server, I only needed to execute shiny-server with the appropriate parameters from the command line. I captured the appropriate call into a script file and call that using the final CMD line in my Dockerfile.
rstudio-server was more tricky. First, I needed to install initscripts to get the dependencies in place so that some of the rstudio scripts would work. After this, executing rstudio-server start would essentially do nothing and provide no error. I traced the call through the various links and found myself in /usr/lib/rstudio-server/bin/rstudio-server. The daemonCmd() function tests cat /proc/1/comm to determine how to start the server. For some reason it was failing, but looking at the script, it seems clear that it needs to execute /etc/init.d/rstudio-server start. If I do that manually or in a Docker CMD line, it seems to work.
I've taken those two CMD line requirements and put them into an sh script that gets called from a CMD line in the Dockerfile.
A bit of a hack, but not bad. I'm happy to hear any other suggestions.
You don't necessarily need to use an init system like systemd.
Essentially, you need to start multiple services, there are existing patterns for this. Check out this page about how to use supervisord to achieve the same thing: https://docs.docker.com/engine/admin/using_supervisord/
I started using Docker and I can say, it is a great concept.
Everything is going fine so far.
I installed docker on ubuntu (my host operating system) , played with images from repository and made new images.
Question:
I want to make an image of the current(Host) operating system. How shall I achieve this using docker itself ?
I am new to docker, so please ignore any silly things in my questions, if any.
I was doing maintenance on a server, the ones we pray not to crash, and I came across a situation where I had to replace sendmail with postfix.
I could not stop the server nor use the docker hub available image because I need to be clear sure I will not have problems. That's why I wanted to make an image of the server.
I got to this thread and from it found ways to reproduce the procedure.
Below is the description of it.
We start by building a tar file of the entire filesystem of the machine (excluding some non necessary and hardware dependent directory - Ok, it may not be as perfect as I intent, but it seams to be fine to me. You'll need to try whatever works for you) we want to clone (as pointed by #Thomasleveil in this thread).
$ sudo su -
# cd /
# tar -cpzf backup.tar.gz --exclude=/backup.tar.gz --exclude=/proc --exclude=/tmp --exclude=/mnt --exclude=/dev --exclude=/sys /
Then just download the file into your machine, import targz as an image into the docker and initialize the container. Note that in the example I put the date-month-day of image generation as image tag when importing the file.
$ scp user#server-uri:path_to_file/backup.tar.gz .
$ cat backup.tar.gz | docker import - imageName:20190825
$ docker run -t -i imageName:20190825 /bin/bash
IMPORTANT: This procedure generates a completely identical image, so it is of great importance if you will use the generated image to distribute between developers, testers and whateever that you remove from it or change any reference containing restricted passwords, keys or users to avoid security breaches.
I'm not sure to understand why you would want to do such a thing, but that is not the point of your question, so here's how to create a new Docker image from nothing:
If you can come up with a tar file of your current operating system, then you can create a new docker image of it with the docker import command.
cat my_host_filesystem.tar | docker import - myhost
where myhost is the docker image name you want and my_host_filesystem.tar the archive file of your OS file system.
Also take a look at Docker, start image from scratch from superuser and this answer from stackoverflow.
If you want to learn more about this, searching for docker "from scratch" is a good starting point.