Automate your android application inside a docker container.

1. © Atos
Mando Stamelaki
software engineer | mobile application developer
Build in Docker with
Jenkins
Automate your android application build inside a docker container

2. How it was

3. | © Atos
How it was…
- Linux Production machine carrying
the Android NDK (low level) Build
environment
- Triggered by a Windows VM, that
also built the high level code
- Manual upload to the Nexus
repository
rsync apk to
Linux m
achine maven upload
to nexus
3
Android Studio
Android SDK & tools
Android NDK
Gradle SSH plugin
get .so build libs

4. | © Atos
Why change it?
- Slow
- Multiple manual steps, significant effort
- Prune to human mistakes.
- Multiply building effort for rebuilds and privates.
- Regular upgrade of libraries
- Maintenance of two building machines
- No option to add build verifications in Gerrit (code review tool)
4

5. The idea

6. | © Atos
First idea
Use just the remote Linux machine to
build Android
Problems:
- need ssh root control to building machine
- no expertise on managing remotely
android tools
- always have in mind to check what tools
we have and update them responsively
- no easy way to manage the machine
environment or version control its status
Our build environment will remain linked
with a dedicated machine for building
6

7. | © Atos
software container platform
- Can package an application
and its dependencies in a
virtual container
- Enable flexibility and
portability on where the
application can run
- automates the deployment of
applications inside software
containers
7

8. | © Atos
Applying to our case...
Have a machine with only docker in it,
…
Looks like a great idea!
...
We can then have multiple machines
with only docker in them.
- Easy check of the tools we have
installed in production
- Everyone will be able to edit and
maintain the dockerfiles that will have
our environment
- Dockerfiles can be in version control
and will check changed and updates
with git
- We don’t have any real machine so no
need for ssh access
8

9. | © Atos
Jenkins
- Continuous integration
- Continuous delivery
- Build and test your software
projects continuously
- Multiple plugins
continuous integration
software
9

10. | © Atos
Jenkins will use as slaves dummy
machines that will only have
docker in them.
For security purposes and to keep
dockerfiles simple we can also add
git and maven in these machines.
10

11. | © Atos
Docker problems
- Decide where we are going to build our images described in dockerfiles
- Store the builded images so as to avoid rebuilds
(Android SDK and NDK take too long to download)
- How to use docker and jenkins as a team?
11

12. | © Atos
Registry?
We need someplace to host
our images
Decided to use docker hub as we
are not planning to add something
confidential in them.
Docker build performed by docker
hub.
12

13. Let's make this work

14. | © Atos
Write our dockerfiles
Oracle Java Development Kit (JDK) docker pull playmobils/oracle-jdk:8
Android Software Development Kit (SDK) docker pull playmobils/android-sdk:23
Android Native Development Kit (NDK) docker pull playmobils/android-ndk:14b
Additional tools that may missing docker pull playmobils/android
https://github.com/PlayMOBils/android-environment
14

15. # Oracle JDK 8
# Pull base image.
FROM debian:jessie
# Set the locale, avoid warnings in regular expressions
RUN
apt-get update &&
apt-get install -qqy --no-install-recommends locales &&
rm -rf /var/lib/apt/lists/*
/var/cache/apt/archives/*
/var/cache/debconf/*-old &&
localedef -i en_US -c -f UTF-8 -A /usr/share/locale/locale.alias en_US.UTF-8
ENV LANG en_US.utf8
ENV LANGUAGE en_US:en
ENV LC_ALL en_US.UTF-8
# Define commonly used JAVA_HOME variable
ENV JAVA_HOME /usr/lib/jvm/java-8-oracle
# Install Deps
# - http://www.oracle.com/technetwork/java/javase/jre-8-readme-2095710.html
RUN
echo deb http://ppa.launchpad.net/webupd8team/java/ubuntu trusty main | tee /etc/apt/sources.list.d/webupd8team-java.list
&&
apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys EEA14886 &&
apt-get update &&
echo oracle-java8-installer shared/accepted-oracle-license-v1-1 select true | debconf-set-selections &&
apt-get -qqy --no-install-recommends install oracle-java8-installer unzip &&
rm -rf ...

16. # Android SDK
FROM playmobils/oracle-jdk:8
ARG DEBIAN_FRONTEND=noninteractive
ENV SDK_HOME /usr/local
# Prerequisite packages libc6:i386 libncurses5:i386 libstdc++6:i386 lib32z1 libbz2-1.0:i386
RUN dpkg --add-architecture i386 &&
apt-get -qq update &&
apt-get install -qqy --no-install-recommends
curl libc6:i386 libncurses5:i386 libstdc++6:i386 lib32z1 libbz2-1.0:i386 &&
rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* /var/cache/apt/archives/* /var/cache/debconf/*-old
ENV ANDROID_HOME "${SDK_HOME}/sdk"
ENV PATH "$PATH:${ANDROID_HOME}/tools"
# Accept License
RUN mkdir -p $ANDROID_HOME/licenses/ &&
echo "8933bad161af4178b1185d1a37fbf41ea5269c55" > $ANDROID_HOME/licenses/android-sdk-license &&
echo "84831b9409646a918e30573bab4c9c91346d8abd" > $ANDROID_HOME/licenses/android-sdk-preview-license
ENV VERSION_SDK_TOOLS "25.2.5"
ENV VERSION_BUILD_TOOLS "23.0.3"
ENV VERSION_TARGET_SDK "23"
ENV SDK_PACKAGES "build-tools-${VERSION_BUILD_TOOLS},android-${VERSION_TARGET_SDK},
addon-google_apis-google-${VERSION_TARGET_SDK},platform-tools,extra-android-m2repository,extra-android-support,
extra-google-google_play_services,extra-google-m2repository"
ENV ANDROID_TOOLS_URL http://dl.google.com/android/repository/tools_r${VERSION_SDK_TOOLS}-linux.zip
RUN curl -L "${ANDROID_TOOLS_URL}" -o tools.zip && unzip /tools.zip -d ${ANDROID_HOME} && rm -vrf /tools.zip
RUN (while [ 1 ]; do sleep 5; echo y; done) | ${ANDROID_HOME}/tools/android update sdk no-ui all filter ${SDK_PACKAGES}

17. # Android NDK
FROM playmobils/android-sdk:23
ARG DEBIAN_FRONTEND=noninteractive
ENV SDK_HOME /usr/local
# Install dependencies
RUN dpkg --add-architecture i386 &&
apt-get -qq update &&
apt-get -qqy install --no-install-recommends file &&
rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* /var/cache/apt/archives/* /var/cache/debconf/*-old
ENV ANDROID_NDK_VERSION r14b
ENV ANDROID_NDK_URL http://dl.google.com/android/repository/android-ndk-${ANDROID_NDK_VERSION}-linux-x86_64.zip
# Download and unzip Android NDK
RUN curl -L "${ANDROID_NDK_URL}" -o android-ndk-${ANDROID_NDK_VERSION}-linux-x86_64.zip
&& unzip android-ndk-${ANDROID_NDK_VERSION}-linux-x86_64.zip -d ${SDK_HOME}
&& rm -rf android-ndk-${ANDROID_NDK_VERSION}-linux-x86_64.zip
ENV ANDROID_NDK_HOME ${SDK_HOME}/android-ndk-${ANDROID_NDK_VERSION}
ENV PATH ${ANDROID_NDK_HOME}:$PATH

18. # Add some missing dependencies
FROM playmobils/android-ndk:14b
ARG DEBIAN_FRONTEND=noninteractive
# How to use
# In order to use it, you need to run it with:
# docker run -v <path to your source>:/src playmobils/android <file to run>
# The command above mounts your directory to where the container expects the source to be and builds it.
# Install dependencies
RUN apt-get -qq update &&
apt-get -qqy install --no-install-recommends gawk bc make git zip &&
rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* /var/cache/apt/archives/* /var/cache/debconf/*-old
# User Sources for Android SDK Manager, to avoid any warnings
RUN echo "count=0" > ~/.android/repositories.cfg

19. Environment set!
Let's build it …

20. | © Atos
docker run -it -v $PWD/osmo:/osmo playmobils/android-ndk:r14b
# cd osmo/Android
# ./gradlew cleanAll
# ./gradlew buildNative
# ./gradlew assembleRelease
interactive terminal mount volume
commands to run inside docker Build Failed: The input device is not a TTY.
“You cannot have interactive console!”
20
open an interactive console with docker and run all
build commands like we do locally

21. | © Atos
docker run -i -v $PWD/osmo playmobils/android-ndk:r14b
sh scripts/android/build.sh
Keep STDIN open
even if not
attached mount volume
a bash file containing all build commands
Build Failed: exec: "scripts/android/build.sh": stat scripts/android/build.sh:
no such file or directory
21
we need a single build command

22. | © Atos
docker run -i -v $PWD/osmo -w /osmo playmobils/android-ndk:r14b
sh scripts/android/build.sh
Keep STDIN open
even if not
attached mount volume
a bash file containing all build commands
Build timed out (after 3 minutes). Marking the build as aborted.
workspace
Jenkins configure:
“Remove the build
timeout if task doesn’t
respond after 3
minutes”
22
use workspace in order to navigate in proper
location in container

23. | © Atos
Build Failed: Gradle cannot read the environment variables that defined in dockerfiles.
ie $ANDROID_HOME, $ANDROID_NDK_HOME
23
single build command with workspace
docker run -i -v $PWD/osmo -w /osmo playmobils/android-ndk:r14b
sh scripts/android/build.sh
Keep STDIN open
even if not
attached mount volume
a bash file containing all build commands
workspace

24. | © Atos
Define them in local.properties,
read them from there
#!/bin/bash
cd OSMO/Android
# create a local.properties file with ndk and sdk in order to used by gradle
echo "sdk.dir=$ANDROID_HOME" > local.properties
echo "ndk.dir=$ANDROID_NDK_HOME" >> local.properties
proxyArgs="-Dhttps.proxyHost=<proxy-host> -Dhttps.proxyPort=<proxy-port>"
echo -e "n ------------- START BUILD ------------- n"
./gradlew $proxyArgs allCleanBuildReleaseApk
echo -e "n ------------- END BUILD ------------- n"
echo -e "n ------------- START TESTS ------------- n"
./gradlew $proxyArgs test # run the unit tests
echo -e "n ------------- END TESTS ------------- n"
24

25. | © Atos
We download gradle wrapper in each run...
We can add the gradle download step in a dockerfile and use docker cache for that!
Downloading https://services.gradle.org/distributions/gradle-2.14.1-all.zip
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................
Unzipping /usr/local/gradle-2.14.1/wrapper/dists/gradle-2.14.1-all/4cj8p00t3e5ni9e8iofg8ghvk7/gradle-2.14.1-all.zip to
/usr/local/gradle-2.14.1/wrapper/dists/gradle-2.14.1-all/4cj8p00t3e5ni9e8iofg8ghvk7
Set executable permissions for:
/usr/local/gradle-2.14.1/wrapper/dists/gradle-2.14.1-all/4cj8p00t3e5ni9e8iofg8ghvk7/gradle-2.14.1/bin/gradle
To honour the JVM settings for this build a new JVM will be forked. Please consider using the daemon:
https://docs.gradle.org/2.14.1/userguide/gradle_daemon.html.
25

26. | © Atos
Local dockerfile for gradle dependencies
FROM playmobils/android:latest
COPY gradlew gradlew
COPY gradle/ gradle
COPY gradle.properties gradle.properties
RUN chmod 755 gradlew
# Run gradle once to download dependencies
RUN ./gradlew -Dhttps.proxyHost=<proxy-host> -Dhttps.proxyPort=<proxy-port>
26

27. | © Atos
Lesson learned with local dockerfile
Build
docker build -t playmobils/osmo OSMO/Android
Dockerfile must be on the root level of project in order to
access files in it.
We can improve build time by using dockerignore and
ignore files not needed for building our dockerfile.
27

28. | © Atos
Builded docker images need a lot of space!!!
- about 5GB, our repository
- Docker images downloaded:
- Suggested 30GB
Trying to rebuild
Builder machine with docker run out of space!!!
REPOSITORY TAG IMAGE ID CREATED SIZE
playmobils/osmo latest 19b78d68ee15 6 weeks ago 4.57 GB
<none> <none> 6f3a5e8e76e1 6 weeks ago 4.57 GB
playmobils/android latest af3b4e8d0d15 6 weeks ago 4.35 GB
older
state of
image
layers
28

29. | © Atos
if [[ $(docker ps -qa --no-trunc --filter "status=exited") ]]; then
echo -e "n Delete old unused containers.n"
docker rm $(docker ps -qa --no-trunc --filter "status=exited")
else
echo -e "n No containers for cleanup.n"
fi
29
Clean docker containers after or before each build
docker run --rm -i -v $PWD/osmo playmobils/android-ndk:r14b
sh scripts/android/build.sh

30. | © Atos
- Solution 1: Jenkins user be a root user.
- we don’t even want to try this one
When building in docker we build as root user
- Problem: Jenkins user cannot delete “root” files it has NO PERMISSIONS…
- Solution 2: Find a way to build in docker with jenkins user.
- use our local dockerfile to define the build user
- change permissions of running gradle file
- build with this user
30
Cannot create file/directory.

31. | © Atos
Local dockerfile for gradle dependencies
FROM playmobils/android:latest
ENV BUILD_USER jenkins_user
RUN useradd -ms /bin/bash -u 1001 $BUILD_USER
WORKDIR /home/$BUILD_USER
COPY gradlew gradlew
COPY gradle/ gradle
COPY gradle.properties gradle.properties
RUN chmod 755 gradlew && chown $BUILD_USER: gradlew &&
chown $BUILD_USER: gradle.properties && chown -R $BUILD_USER: gradle
USER $BUILD_USER
RUN ./gradlew # Run gradle once to download dependencies
31

32. Improvements

33. | © Atos
We noticed that failed statuses from docker not
passed in Jenkins
33
./gradlew $proxyArgs allCleanBuildReleaseApk; gradlew_return_code=$?
if (( gradlew_return_code != 0 )); then
echo "GRADLE BUILD FAILED!"
exit 1
fi

34. | © Atos
▶ Created a folder for GRADLE_HOME in the host machine
▶ Passed this folder as volume to docker
– Build time dropped to 9 min
– We noticed a couple of problems though that are due to fileHashes.lock
but this only happens when CI and release run in parallel
Cache the .gradle dependencies
34
docker run --rm -i -v $GRADLE_HOME:/home/jenkins_user/.gradle
-v $PWD/osmo
playmobils/android-ndk:r14b sh scripts/android/build.sh

35. | © Atos
▶ Save them to a file
▶ Pass this parameters in docker
Jenkins parameters needed inside docker
35
docker run --rm -i --env-file=env_vars.txt
-v $GRADLE_HOME:/home/jenkins_user/.gradle
-v $PWD/osmo
playmobils/android-ndk:r14b sh scripts/android/build.sh
env | grep GIT_ > env_vars.txt

36. | © Atos
▶ Changed all docker images to use the version tag
– SDK: playmobils/android-sdk:26
– NDK: playmobils/android-ndk:26_14b
– Tools: playmobils/android:26_14b
– Local: playmobils/osmo:26_14b
Build for different API versions
36
$ docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
playmobils/osmo 26_14b 6c47fdd2ad7a 8 days ago 5.09GB
playmobils/osmo 27_14b d2b7addfed45 10 days ago 5.09GB
playmobils/android 27_14b 495a6cb3a3ab 10 days ago 4.84GB
playmobils/android 26_14b f5609b45b666 10 days ago 4.84GB

37. Putting it all together

38. | © Atos
VERSION=26_14b or VERSION=27_14b
- docker pull playmobils/android:$VERSION
- docker build -t playmobils/osmo:$VERSION OSMO/Android
- docker run --rm -i --env-file=env_vars.txt -v $PWD:$DWORKSPACE
-v $GRADLE_HOME:/home/jenkins_user/.gradle
-w /home/jenkins_user/osmo/
playmobils/osmo:$VERSION
/bin/bash scripts/android/BuildAndroidApp.sh
38
Full Jenkins shell script

39. some successful
basic commands
First & second
successful build
After manually
deleting files
two in a row builds
without any
intervene user
jenkins build
success
39

40. 30-40 min
the image is not downloaded.
10-20 min
the image is present.
9-13 min
with the cache usage
Build time diagram

41. | © Atos
What we learned!
▶ Docker may need more disk space than expected.
▶ Dockerfiles and the kernel used for base images is minimal without the
essential tools be prepared to add anything missing from your build.
▶ A dockerfile that copy / add external files during build have to be in root
directory (symbolic links or relative paths to parents are not accepted).
▶ In jenkins you cannot build as root, create your jenkins user in dockerfile.
▶ In jenkins you don't have interactive console use a single line script including
your code.
▶ When you have dependable dockerfiles pulling / building the latest doesn't
mean that changes in other files will pulled / build.
41

42. | © Atos
References
- https://www.docker.com/
- https://docs.docker.com/
- http://blog.zot24.com/tips-tricks-docker/
- https://jenkins-ci.org/
42
- https://github.com/PlayMOBils/android-environment
- https://hub.docker.com/r/playmobils/
Dockerfiles and images:

43. Questions ?

44. © Atos
Thank you!
Mando Stamelaki
software engineer | mobile application developer
adamantia-eleni.stamelaki@atos.net