Before you get started with contributing to LocalStack, make sure you’ve familiarized yourself with LocalStack from the perspective of a user.
You can follow our getting started guide.
Once LocalStack runs in your Docker environment and you’ve played around with the LocalStack and awslocal
CLI, you can move forward to set up your developer environment.
You will need the following tools for the local development of LocalStack.
- Python and
pip
- We recommend to use a Python version management tool like
pyenv
. This way you will always use the correct Python version as defined in.python-version
.
- We recommend to use a Python version management tool like
- Node.js & npm
- Docker
We recommend you to individually install the above tools using your favorite package manager. For example, on macOS, you can use Homebrew to install the above tools.
To make contributions to LocalStack, you need to be able to run LocalStack in host mode from your IDE, and be able to attach a debugger to the running LocalStack instance. We have a basic tutorial to cover how you can do that.
The basic steps include:
- Fork the localstack repository on GitHub https://github.com/localstack/localstack/
- Clone the forked localstack repository
git clone git@github.com:<GITHUB_USERNAME>/localstack.git
- Ensure you have
python
,pip
,node
, andnpm
installed.
Note
You might also need java
for some emulated services.
- Install the Python dependencies using
make install
.
Note
This will install the required pip dependencies in a local Python 3 venv
directory called .venv
(your global Python packages will remain untouched).
Depending on your system, some pip
modules may require additional native libs installed.
- Start localstack in host mode using
make start
We generally recommend using this command to build the localstack/localstack
Docker image locally (works on Linux/MacOS):
IMAGE_NAME="localstack/localstack" ./bin/docker-helper.sh build
In host mode, additional dependencies (e.g., Java) are required for developing certain AWS-emulated services (e.g., DynamoDB). The required dependencies vary depending on the service, Configuration, operating system, and system architecture (i.e., x86 vs ARM). Refer to our official Dockerfile and our package installer LPM for more details.
LocalStack runs its own DNS server which listens for requests on port 53. This requires root permission. When LocalStack starts in host mode it runs the DNS server as sudo, so a prompt is triggered asking for the sudo password. This is annoying during local development, so to disable this functionality, use DNS_ADDRESS=0
.
Note
We don't recommend disabling the DNS server in general (e.g. in Docker) because the DNS server enables seamless connectivity to LocalStack from different environments via the domain name localhost.localstack.cloud
.
- JPype1 might require
g++
to fix a compile error on ARM Linuxgcc: fatal error: cannot execute ‘cc1plus’
- Used in EventBridge, EventBridge Pipes, and Lambda Event Source Mapping for a Java-based event ruler via the opt-in configuration
EVENT_RULE_ENGINE=java
- Introduced in #10615
- Used in EventBridge, EventBridge Pipes, and Lambda Event Source Mapping for a Java-based event ruler via the opt-in configuration
- Node.js is required for running LocalStack tests because the test fixture for CDK-based tests needs Node.js
- macOS users need to configure
LAMBDA_DEV_PORT_EXPOSE=1
such that the host can reach Lambda containers via IPv4 in bridge mode (see #7367).
- Requires Java to execute to invoke the AWS event-ruler using JPype, a Python to Java bridge.
- Set
JAVA_HOME
to a JDK installation. For example:JAVA_HOME=/opt/homebrew/Cellar/openjdk/21.0.2
- Fork our moto repository on GitHub https://github.com/localstack/moto
- Clone the forked moto repository
git clone git@github.com:<GITHUB_USERNAME>/moto.git
(using thelocalstack
branch) - Within the localstack repository, install moto in editable mode:
# Assuming the following directory structure:
#.
#├── localstack
#└── moto
cd localstack
source .venv/bin/activate
pip install -e ../moto
- If
virtualenv
chooses system python installations before your pyenv installations, manually initializevirtualenv
before runningmake install
:virtualenv -p ~/.pyenv/shims/python3.10 .venv
. - Terraform needs version <0.14 to work currently. Use
tfenv
to manage Terraform versions comfortable. Quick start:tfenv install 0.13.7 && tfenv use 0.13.7
- Set env variable
LS_LOG='trace'
to print everyhttp
request sent to localstack and their responses. It is useful for debugging certain issues. - Catch linter or format errors early by installing Git pre-commit hooks via
pre-commit install
. pre-commit installation:pip install pre-commit
orbrew install pre-commit
.