Add Dockerfile for Ubuntu 20.04

ubuntu-20_04-aosp.dockerfile

@@ -0,0 +1,42 @@
+# Originally from: https://android-review.googlesource.com/c/platform/build/+/1161367
+FROM ubuntu:20.04
+ARG userid=1000
+ARG groupid=1000
+ARG username=aosp
+ARG http_proxy
+
+# Using separate RUNs here allows Docker to chache each update
+RUN DEBIAN_FRONTEND="noninteractive" apt-get update
+
+# Make sure the base image is up to date
+RUN DEBIAN_FRONTEND="noninteractive" apt-get upgrade -y
+
+# Install apt-utils to make apt run more smoothly
+RUN DEBIAN_FRONTEND="noninteractive" apt-get install -y apt-utils
+
+# Install the packages needed for the build
+RUN DEBIAN_FRONTEND="noninteractive" apt-get install -y git-core gnupg flex bison build-essential \
+	zip curl zlib1g-dev gcc-multilib g++-multilib libc6-dev-i386 lib32ncurses5-dev \
+	x11proto-core-dev libx11-dev lib32z1-dev libgl1-mesa-dev libxml2-utils xsltproc unzip \
+	fontconfig libncurses5 procps rsync
+
+# Disable some gpg options which can cause problems in IPv4 only environments
+RUN mkdir ~/.gnupg && chmod 600 ~/.gnupg && echo "disable-ipv6" >> ~/.gnupg/dirmngr.conf
+
+# Download and verify repo
+RUN gpg --keyserver pool.sks-keyservers.net --recv-key 8BB9AD793E8E6153AF0F9A4416530D5E920F5C65
+RUN curl -o /usr/local/bin/repo https://storage.googleapis.com/git-repo-downloads/repo
+RUN curl https://storage.googleapis.com/git-repo-downloads/repo.asc | gpg --verify - /usr/local/bin/repo
+RUN chmod a+x /usr/local/bin/repo
+
+# Create the home directory for the build user
+RUN groupadd -g $groupid $username \
+ && useradd -m -s /bin/bash -u $userid -g $groupid $username
+COPY gitconfig /home/$username/.gitconfig
+RUN chown $userid:$groupid /home/$username/.gitconfig
+
+# Create a directory which we can use to build the AOSP
+RUN mkdir /aosp && chown $userid:$groupid /aosp && chmod ug+s /aosp
+
+WORKDIR /home/$username
+USER $username