diff --git a/tools/docker/.gitignore b/tools/docker/.gitignore
new file mode 100644
index 0000000..df0b367
--- /dev/null
+++ b/tools/docker/.gitignore
@@ -0,0 +1 @@
+gitconfig
diff --git a/tools/docker/Dockerfile b/tools/docker/Dockerfile
new file mode 100644
index 0000000..ec65aaf
--- /dev/null
+++ b/tools/docker/Dockerfile
@@ -0,0 +1,25 @@
+FROM ubuntu:14.04
+ARG userid
+ARG groupid
+ARG username
+
+RUN apt-get update && apt-get install -y git-core gnupg flex bison gperf build-essential zip curl zlib1g-dev gcc-multilib g++-multilib libc6-dev-i386 lib32ncurses5-dev x11proto-core-dev libx11-dev lib32z-dev ccache libgl1-mesa-dev libxml2-utils xsltproc unzip python openjdk-7-jdk
+
+RUN curl -o jdk8.tgz https://android.googlesource.com/platform/prebuilts/jdk/jdk8/+archive/master.tar.gz \
+ && tar -zxf jdk8.tgz linux-x86 \
+ && mv linux-x86 /usr/lib/jvm/java-8-openjdk-amd64 \
+ && rm -rf jdk8.tgz
+
+RUN curl -o /usr/local/bin/repo https://storage.googleapis.com/git-repo-downloads/repo \
+ && echo "e147f0392686c40cfd7d5e6f332c6ee74c4eab4d24e2694b3b0a0c037bf51dc5  /usr/local/bin/repo" | sha256sum --strict -c - \
+ && chmod a+x /usr/local/bin/repo
+
+RUN groupadd -g $groupid $username \
+ && useradd -m -u $userid -g $groupid $username \
+ && echo $username >/root/username \
+ && echo "export USER="$username >>/home/$username/.gitconfig
+COPY gitconfig /home/$username/.gitconfig
+RUN chown $userid:$groupid /home/$username/.gitconfig
+ENV HOME=/home/$username
+
+ENTRYPOINT chroot --userspec=$(cat /root/username):$(cat /root/username) / /bin/bash -i
diff --git a/tools/docker/README.md b/tools/docker/README.md
new file mode 100644
index 0000000..304fd18
--- /dev/null
+++ b/tools/docker/README.md
@@ -0,0 +1,18 @@
+The Dockerfile in this directory sets up an Ubuntu Trusty image ready to build
+a variety of Android branches (>= Lollipop). It's particulary useful to build
+older branches that required 14.04 if you've upgraded to something newer.
+
+First, build the image:
+```
+# Copy your host gitconfig, or create a stripped down version
+$ cp ~/.gitconfig gitconfig
+$ docker build --build-arg userid=$(id -u) --build-arg groupid=$(id -g) --build-arg username=$(id -un) -t android-build-trusty .
+```
+
+Then you can start up new instances with:
+```
+$ docker run -it --rm -v $ANDROID_BUILD_TOP:/src android-build-trusty
+> cd /src; source build/envsetup.sh
+> lunch aosp_arm-eng
+> m -j50
+```