Installing dependencies

If your collector or cataloger requires dependencies, you have two options depending on your execution environment:

1. Custom Docker image - Bake dependencies into your image for containerized execution

2. Install script - Use install.sh for native execution

Custom Docker Image

When running in containers, create a custom Docker image with all dependencies pre-installed. This provides faster startup times, reproducible builds, and eliminates network dependencies at runtime.

Create a Dockerfile that inherits from the official earthly/lunar-scripts image:

FROM earthly/lunar-scripts:v1.0

# Install system dependencies
RUN apt-get update && apt-get install -y jq curl && rm -rf /var/lib/apt/lists/*

# Install additional tools
RUN curl -L "https://github.com/keilerkonzept/dockerfile-json/releases/download/v1.2.2/dockerfile-json_Linux_x86_64.tar.gz" | tar xz \
    && mv dockerfile-json /usr/local/bin/

Then configure your plugin or lunar-config.yml to use this image:

image: my-org/my-custom-image:v1.0

For more details on image configuration, see Images.

Install Script for Native Execution

When running with image: native (no container), you can install dependencies using an install.sh script in the same directory as your lunar-config.yml, lunar-collector.yml or lunar-cataloger.yml file.

This install script is executed only once in each environment, before the collector or cataloger is run.

Example

#!/bin/bash
curl -L "https://github.com/keilerkonzept/dockerfile-json/releases/download/v1.2.2/dockerfile-json_Linux_x86_64.tar.gz" | tar xz
mv dockerfile-json "$LUNAR_BIN_DIR/"

Installation path

If you need to install a binary that will be used in the collector or cataloger, you can use the LUNAR_BIN_DIR environment variable. This will ensure the binary is available in the PATH.

Multi-platform support

For platform-specific logic, you can use install-<os>-<arch>.sh or install-<os>.sh files. Making your script multi-platform is useful for local development when your local platform may differ from the one Lunar's runners or your CI is running on.

Platform-specific scripts are checked for existence in the following order:

1. install-<os>-<arch>.sh

2. install-<os>.sh

3. install.sh

Only the first script found is executed.

Examples of valid platform-specific script names:

• install-linux-amd64.sh

• install-linux-arm64.sh

• install-linux.sh

• install-darwin-arm64.sh

• install-darwin.sh

Development convenience with earthly/lunar-scripts

The official earthly/lunar-scripts image automatically executes any install.sh script found in the plugin directory as part of its entrypoint. This is a convenience feature for quick development iteration, but baking dependencies into your image provides faster startup times in production.

To override this behavior, you can change the ENTRYPOINT in your Dockerfile. For example:

ENTRYPOINT ["/bin/bash"]