I am trying to connect an Android emulator (running on my MacOS) to my linux-based docker container.

Here's my dockerfile:

# Use an official Linux base image (Ubuntu)
FROM cirrusci/flutter:latest

# Install dependencies
RUN apt-get update && apt-get install -y wget curl unzip git \
    openjdk-17-jdk lib32stdc++6 lib32z1 \
    libglu1-mesa libxi6 libxrender1 libxrandr2 libxcursor1 \
    libpulse0 libnss3 libatk-bridge2.0-0 libxcomposite1 libasound2 \
    gnupg2 socat net-tools clang cmake ninja-build pkg-config libgtk-3-dev

# Set Java environment variables
ENV JAVA_HOME=/usr/lib/jvm/java-17-openjdk-amd64
ENV PATH="$JAVA_HOME/bin:$PATH"

# Install Android SDK
ENV ANDROID_SDK_ROOT=/opt/android-sdk
RUN mkdir -p $ANDROID_SDK_ROOT && cd $ANDROID_SDK_ROOT && \
    wget .zip -O cmdline-tools.zip && \
    unzip cmdline-tools.zip -d $ANDROID_SDK_ROOT && \
    rm cmdline-tools.zip && \
    mv $ANDROID_SDK_ROOT/cmdline-tools $ANDROID_SDK_ROOT/cmdline-tools-latest && \
    mkdir -p $ANDROID_SDK_ROOT/cmdline-tools/latest && \
    mv $ANDROID_SDK_ROOT/cmdline-tools-latest/* $ANDROID_SDK_ROOT/cmdline-tools/latest/

# Set Android SDK environment variables
ENV PATH="$ANDROID_SDK_ROOT/cmdline-tools/latest/bin:$ANDROID_SDK_ROOT/platform-tools:$PATH"

# Accept Android SDK licenses and install required components
RUN yes | sdkmanager --licenses && \
    sdkmanager "platform-tools" "platforms;android-34" "build-tools;34.0.0" "cmdline-tools;latest"

# Install Google Chrome (for Flutter Web)
RUN wget .deb && \
    apt-get install -y ./google-chrome-stable_current_amd64.deb && \
    rm google-chrome-stable_current_amd64.deb

# Set Chrome environment variable for Flutter
ENV CHROME_EXECUTABLE=/usr/bin/google-chrome

# Install Flutter from the official GitHub repository (includes .git metadata)
RUN rm -rf /sdks/flutter && git clone .git /sdks/flutter

# Set Flutter environment variables
ENV FLUTTER_HOME=/sdks/flutter
ENV PATH="$FLUTTER_HOME/bin:$PATH"

# Ensure Flutter is in a valid state
RUN flutter channel stable && flutter upgrade && flutter doctor

# Set working directory
WORKDIR /app
COPY . /app

I build my container like this: docker build -t joshua/gs_ui:1.2 .

I start my docker container with network access: docker run --rm -it --network host joshua/gs_ui:1.2 bash

Running flutter doctor -v from inside the docker container gives me this:

[✓] Flutter (Channel stable, 3.29.2, on Ubuntu 22.04.1 LTS 6.10.14-linuxkit, locale en_US.UTF-8) [584ms]
    • Flutter version 3.29.2 on channel stable at /sdks/flutter
    • Upstream repository .git
    • Framework revision c236373904 (4 days ago), 2025-03-13 16:17:06 -0400
    • Engine revision 18b71d647a
    • Dart version 3.7.2
    • DevTools version 2.42.3

[✓] Android toolchain - develop for Android devices (Android SDK version 33.0.1) [4.9s]
    • Android SDK at /opt/android-sdk-linux
    • Platform android-33, build-tools 33.0.1
    • ANDROID_HOME = /opt/android-sdk-linux
    • ANDROID_SDK_ROOT = /opt/android-sdk
    • Java binary at: /usr/lib/jvm/java-17-openjdk-amd64/bin/java
      This JDK is specified by the JAVA_HOME environment variable.
      To manually set the JDK path, use: `flutter config --jdk-dir="path/to/jdk"`.
    • Java version OpenJDK Runtime Environment (build 17.0.14+7-Ubuntu-122.04.1)
    • All Android licenses accepted.

[✓] Chrome - develop for the web [47ms]
    • CHROME_EXECUTABLE = /usr/bin/google-chrome

[✓] Linux toolchain - develop for Linux desktop [878ms]
    • Ubuntu clang version 14.0.0-1ubuntu1.1
    • cmake version 3.22.1
    • ninja version 1.10.1
    • pkg-config version 0.29.2

[!] Android Studio (not installed) [43ms]
    • Android Studio not found; download from .html
      (or visit /to/linux-android-setup for detailed instructions).

[✓] Connected device (2 available) [704ms]
    • Linux (desktop) • linux  • linux-x64      • Ubuntu 22.04.1 LTS 6.10.14-linuxkit
    • Chrome (web)    • chrome • web-javascript • Google Chrome 134.0.6998.88

[✓] Network resources [719ms]
    • All expected network resources are available.

! Doctor found issues in 1 category.

• I boot up the emulator and in my zsh terminal I run, adb shell ip route to get the IP address of the emulator.
• Then from inside the docker container, I run, adb connect 10.0.2.16:5555 (or whatever the given emulator IP address is). and adb devices

This is the response I typically get:

* daemon not running; starting now at tcp:5037
* daemon started successfully
failed to connect to '10.0.2.16:5555': Connection refused
List of devices attached

I've tried running the following socat commands to forward the emulator's ports like this:

socat tcp-listen:5554,bind=$ip,fork tcp:127.0.0.1:5554 &
socat tcp-listen:5555,bind=$ip,fork tcp:127.0.0.1:5555 &
socat udp-listen:5554,bind=$ip,fork udp:127.0.0.1:5554 &
socat udp-listen:5555,bind=$ip,fork udp:127.0.0.1:5555 &

And then repeating the adb connect command.

I've also tried the above process using different emulators:

1. Using Android Studio Pixel_9 Android emulator started up directly from Android Studio.
2. A new emulator with Google APIs image by: a: Installing ARM64, sdkmanager --install "system-images;android-33;google_apis;arm64-v8a" b: avdmanager create avd -n Pixel_9_ARM64 -k "system-images;android-33;google_apis;arm64-v8a" c: emulator -avd Pixel_9_ARM64 -no-snapshot -gpu host -no-boot-anim
3. A third-party emulator called, Genymotion.

STILL NO LUCK.

I pretty much keep getting, "failed to connect" without any details as to why it failed to connect.

Anyone know what the issue is/could be?