If you ever tried to configure CircleCi to build your Android App you would probably go straight to the CircleCi’s official language guide for Android. Which is a reasonable course of action.
CircleCi have a docker executor with your name on it. If your name is circleci/android:api-25-alpha or similar. A bit of tinkering and it works! Your project builds and, in general, acts like a CI pipeline should do.
Life is hunky-dory, all is calm, all is well, until…
You start adding new features, or (god forbid) you develop your App using React-Native, and gradually your build gets a bit more involved.
Enter the Java Out of Memory issue!
Java Out Of Memory (OOM) Errors in CircleCi’s Docker Executor
▸ FAILURE: Build failed with an exception.
▸ * What went wrong:
▸ Execution failed for task ‘:app:bundleReleaseJsAndAssets’.
▸ > Process ‘command ‘node’’ finished with non-zero exit value 137
This is a Java OOM error, although it’s not entirly clear what’s happening from the build output. A 137 error and a vague error message isn’t overly descriptive. A bit of googling and it becomes clearer. The particular error above was provoked in a previously building React-Native Android project, after upgrade to use Android’s v28 SDK. It bums out when it tries to execute a node command to package up the JavaScript in a deployable bundle, but the source of the error isn’t important. There’s nothing wrong with the command, it has just pushed the docker executor over its memory limit.
Breaking Docker with Java
Turns out this isn’t that hard to do. A combination of Java having an overly greedy build process, less than ideal default configuration for Docker, and CircleCi assigning only 4GB of memory to their docker executors makes it easier than it should be. CircleCi have recognised this as an issue an have a helpful blog post which may help you. I tried the suggestions mentioned in that blog and it didn’t help. My memory hungry React-Native Android build was just eating ALL THE MEMORY.
The (CircleCi) Solution
If all else fails, CircleCi says upgrade so that your project can use the resource_class feature (and a whole bunch of other cool stuff btw). Throw more memory at the problem! (At a small cost!)
Trouble with this upgrade is that you can’t just upgrade the problem Project. You have to pay n dollars per project, and if you have a few dozen projects that cost will stack up, especially as, at this point, you probably only need the additional features to solve your single problem project.
But don’t despair, there is another way…
The other (cheaper) way to fix the problem
Luckily CircleCi suite of executors contains a more powerful agent, and we can use it (with a bit of configuration) in the standard plan!
I present to you the machine executor which has 8GB of RAM! 
…but doesn’t have the Android SDK loaded 
So lets configure it so it has ALL the stuff
This configuration will be for Android and React-Native
Let’s briefly talk about what software the machine executor does have installed as standard that will help us:
- Ubuntu 14.04
- Java
- wget
- zip/unzip
- git
…and to help React Native
- node v6.10
- python
- ruby
First of all lets select the machine executor, and environment variables we’ll use later, and checkout our project.
version: 2
jobs:
build_android:
environment:
BASH_ENV: envrc
machine:
enabled: true
steps:
- checkout
The main software we need is the Android Studio SDK to build the App. At current time of writing the SDK version is v28 (Android 9 API), and the download of the SDK tools can be found on the Android Studio downloads page.
As an aside I can see that you used to be able to download these tools using the apt utility, so I’m expecting the method of getting these tools to change in the future as Google changes it mind over the best delivery mechanism.
- run:
name: Download android sdk
command: |
cd ..
mkdir android-sdk
cd android-sdk
wget https://dl.google.com/android/repository/sdk-tools-linux-4333796.zip
unzip sdk-tools-linux-4333796.zip
Now we can add these tools to $PATH environment variable so they will be usable in later bash commands.
- run:
name: Set env vars for android sdk tools
command: |
echo '
export ANDROID_HOME=$HOME/android-sdk
export PATH=$PATH:$HOME/android-sdk/tools/bin
export PATH=$PATH:$HOME/android-sdk/platform-tools' >> envrc
Now we have the SDK software available on the machine executor, but there is one last hurdle before they can be used successfully to build our project. Google wants you to accept their terms and conditions before issuing a license to use these command line tools, so we have to accept all licenses via the command line before going forward. This was a bit tricky, but luckily I found this conversation on CircleCi’s forum which had the solution (to pipe ‘yes’ to the accept licenses command and return a non-exit response).
- run:
name: Accept sdk licenses
command: |
yes | sdkmanager --licenses || exit 0
yes | sdkmanager --update || exit 0
So there you go, that’s all you need to build your Android app project, but since my project also has React-Native, I’ll share how to get that running too…
React Native supporting software
Let’s install the React Native required bits, namely upgrade to NodeJS 8, so I can then use Yarn, and Watchman for the React Native packager.
- run:
name: Install watchman
command: |
cd ~
git clone https://github.com/facebook/watchman.git
cd watchman/
git checkout v4.7.0
sudo apt-get install -y autoconf automake build-essential python-dev
./autogen.sh
./configure
make
sudo make install
watchman --version
echo 999999 | sudo tee -a /proc/sys/fs/inotify/max_user_watches && echo 999999 | sudo tee -a /proc/sys/fs/inotify/max_queued_events && echo 999999 | sudo tee -a /proc/sys/fs/inotify/max_user_instances && watchman shutdown-server
- run:
name: Install node@8.16.0 (need to install latest version of `yarn`)
command: |
set +e
curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.33.5/install.sh | bash
export NVM_DIR="/opt/circleci/.nvm"
[ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"
nvm install v8.16.0
nvm alias default v8.16.0
echo 'export NVM_DIR="/opt/circleci/.nvm"' >> envrc
echo "[ -s \"$NVM_DIR/nvm.sh\" ] && . \"$NVM_DIR/nvm.sh\"" >> envrc
- run:
name: Install yarn
command: |
curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | sudo apt-key add -
echo "deb https://dl.yarnpkg.com/debian/ stable main" | sudo tee /etc/apt/sources.list.d/yarn.list
sudo apt-get update && sudo apt-get install yarn
You can then build your Android Apps with ./gradlew assembleRelease --no-daemon --max-workers 2 or try using Fastlane for automated uploads to Android Playstore 
Thank you for reading, hope this blog post helps some of you! 