Audio raw data callback not working when running docker container as non-root user

Meeting SDK
,
1

Hi All,

I am running our app with Zoom Linux SDK v6.1.1 integrated within a Docker container based on our in-house red hat docker image.

For security and compliance reason, we have to run the container as a non-root user and these are errors I am getting:

ALSA lib control.c:1528:(snd_ctl_open_noupdate) Invalid CTL 
ALSA lib pcm.c:2664:(snd_pcm_open_noupdate) Unknown PCM

We suspect that the issue is related to missing some unknown permission preventing the Zoom SDK from accessing the pulseaudio system when the container is run as a non-root user (in our case, the user is apiq).

When we run the container as root, the ALSA errors do not occur, and the bot is able to process the audio raw data without any issues.

Could you advise on how we can resolve this issue to process audio raw data while running the container with a non-root user?

For reference, here is the Dockerfile we’re using. The issue can be resolved if we remove the line USER apiq and run the container as root, which is not what we want though.

Dockerfile

FROM sfdc_rhel9:74 AS base

ENV project=eci-realtime-zoom

#  Install Dependencies
RUN dnf update \
    && dnf install -y \
    ca-certificates \
    cmake3 \
    gcc \
    gcc-c++ \
    gdb \
    git \
    libatomic \
    kernel-headers \
    dbus-libs \
    make \
    mesa-libgbm \
    mesa-libGL \
    glib2 \
    glib2-devel \
    openssl-devel \
    libX11-xcb \
    xcb-util-image \
    xcb-util-keysyms \
    xcb-util-renderutil \
    xcb-util-wm \
    libXfixes \
    perl \
    perl-IPC-Cmd \
    pkgconf \
    tar \
    unzip \
    zip

# Install ALSA
RUN dnf install -y alsa-lib alsa-utils alsa-plugins-pulseaudio --allowerasing

# Install Pulseaudio
RUN dnf install -y pulseaudio pulseaudio-utils --allowerasing

WORKDIR /opt
RUN git clone --depth 1 https://github.com/Microsoft/vcpkg.git \
    && ./vcpkg/bootstrap-vcpkg.sh -disableMetrics \
    && ln -s /opt/vcpkg/vcpkg /usr/local/bin/vcpkg \
    && vcpkg install poco[netssl,crypto] expat

## Install Tini
## Why Tini? https://github.com/krallin/tini/issues/8
ENV TINI_VERSION v0.19.0
ADD https://github.com/krallin/tini/releases/download/${TINI_VERSION}/tini /tini
RUN chmod +x /tini

RUN groupadd apiq && useradd -m -u 7447 -g apiq apiq
RUN usermod -aG pulse-access,audio,root apiq
RUN usermod -aG pulse-access,audio root
RUN chmod -R 777 /var  && chmod -R 777 /root \
&& mkdir -p /run/user/7447 && chown -R apiq:apiq /run/user/7447


FROM base

WORKDIR /home/apiq/$project

RUN chown -R apiq:apiq /home/apiq/$project/

USER apiq

COPY target/zoomsdk zoomsdk
COPY bin/run.sh run.sh

RUN mkdir -p lib/zoomsdk/qt_libs/Qt/lib

COPY lib/zoomsdk/libmeetingsdk.so.1 lib/zoomsdk/libmeetingsdk.so.1
COPY lib/zoomsdk/qt_libs/Qt/lib lib/zoomsdk/qt_libs/Qt/lib
COPY config.toml config.toml

ENTRYPOINT ["./run.sh"]

run.sh

#!/usr/bin/env bash

BotName=$1
JoinUrl=$2

# directory for application output
mkdir -p out

setup-pulseaudio() {

  export XDG_RUNTIME_DIR=/run/user/$(id -u apiq)

  # Enable dbus
  if [[  ! -d /var/run/dbus ]]; then
    mkdir -p /var/run/dbus
    dbus-uuidgen > /var/lib/dbus/machine-id
    dbus-daemon --config-file=/usr/share/dbus-1/system.conf --print-address
  fi

  # Cleanup to be "stateless" on startup, otherwise pulseaudio daemon can't start
  rm -rf /var/run/pulse /var/lib/pulse /root/.config/pulse/
  mkdir -p ~/.config/pulse/ && cp -r /etc/pulse/* "$_"

  pulseaudio -D --exit-idle-time=-1 --system --disallow-exit

  # Create a virtual speaker output

  pactl load-module module-null-sink sink_name=SpeakerOutput
  pactl set-default-sink SpeakerOutput
  pactl set-default-source SpeakerOutput.monitor

  # Make config file
  echo -e "[General]\nsystem.audio.type=pulse" > ~/.config/zoomus.conf
}

run() {
  # Set up and start pulseaudio
  setup-pulseaudio &> /dev/null || exit;
  exec ./zoomsdk --display-name $BotName --join-url $JoinUrl
}

run;

exit

Thank you for your assistance.

2

@tzhou

There are probably 2 things i would try.
These are probably applicable for both Meeting SDK and Video SDK

1st is to make sure pulseaudio is setup

2nd is to make sure that there is a configuration file added

3

Hey @tzhou, if you’re dealing with raw audio callback issues when running a Docker container as a non-root user, you might want to check out the Recall.ai API.

It’s a simple 3rd party API that lets you use meeting bots to get raw audio/video/metadata from meetings without you needing to spend months to build, scale and maintain these bots.

Here are the API docs: https://docs.recall.ai

4

Hi @chunsiong.zoom
I’ve looked at the pulseaudio setup script shared in the 1st link, of which the only user permission related configuration is adding the root user added to the pulse-access and audio group.

# add root

 adduser root pulse-access

 adduser root audio

The similar configuration has been applied as what I’ve shared in my docker file:
I created a new user apiq with user id 7447. I’ve added both the root and apiq users to the pulse-access and audio group

RUN groupadd apiq && useradd -m -u 7447 -g apiq apiq
RUN usermod -aG pulse-access,audio,root apiq
RUN usermod -aG pulse-access,audio root
RUN chmod -R 777 /var  && chmod -R 777 /root \
&& mkdir -p /run/user/7447 && chown -R apiq:apiq /run/user/7447

It is still not working if I run the docker container as apiq user by adding to the docker file the line below:

USER apiq

I’m stilling seeing these errors:

ALSA lib control.c:1528:(snd_ctl_open_noupdate) Invalid CTL 
ALSA lib pcm.c:2664:(snd_pcm_open_noupdate) Unknown PCM